Akeega (niraparib tosylate/abiraterone acetate)
Antineoplastic-Poly (ADP-Ribose) polymerase (PARP) inhibitor Oral Tablet
Last reviewed · Source: First Databank (FDB) drug data
Overview
Niraparib tosylate monohydrate and abiraterone acetate, a fixed-combination preparation containing a poly(adenosine diphosphate (ADP)-ribose) polymerase (PARP) inhibitor (niraparib) and a17alpha-hydroxylase/C17,20-lyase (CYP17) inhibitor (abiraterone), is an antineoplastic agent.
Niraparib is an inhibitor of poly(ADP-ribose) polymerase (PARP) enzymes, including PARP-1 and PARP-2, that play a role in DNA repair. In vitro studies have shown that niraparib-induced cytotoxicity may involve inhibition of PARP enzymatic activity and increased formation of PARP-DNA complexes resulting in DNA damage, apoptosis, and cell death. Increased niraparib-induced cytotoxicity was observed in tumor cell lines with or without deficiencies inBRCA 1/2.
Niraparib decreased tumor growth in mouse xenograft models of human cancer cell lines with deficiencies inBRCA 1/2 and in human patient-derived xenograft tumor models with homologous recombination deficiency that had either mutated or wild-type BRCA 1/2.
Androgen-sensitive prostatic carcinoma responds to treatment that decreases androgen levels. Androgen deprivation therapies, such as treatment with gondatropin-releasing-hormone (GnRH) agonists or orchiectomy, decrease androgen production in the testes but do not affect androgen production by the adrenals or in the tumor. Abiraterone acetate is converted in vivo to abiraterone, an androgen biosynthesis inhibitor, that inhibits 17alpha-hydroxylase/C17,20-lyase (CYP17).
This enzyme is expressed in testicular, adrenal, and prostatic tumor tissues and is required for androgen biosynthesis. CYP17 catalyzes 2 sequential reactions: 1) the conversion of pregnenolone and progesterone to their 17alpha-hydroxy derivatives by 17alpha-hydroxylase activity and, 2) the subsequent formation of dehydroepiandrosterone (DHEA) and androstenedione, respectively, by C17,20-lyase activity(DHEA and androstenedione areandrogen precursors of testosterone). Inhibition of CYP17 by abiraterone can also result in increased mineralocorticoid production by the adrenals.
Abiraterone decreased serum testosterone and other androgens in patients in the placebo-controlled clinical trial. It is not necessary to monitor the effect of abiraterone on serum testosterone levels. Changes in serum prostate specific antigen (PSA) levels may be observed but have not been shown to correlate with clinical benefit in individual patients.
In mouse xenograft models of prostate cancer, the combination of niraparib and abiraterone acetate increased anti-tumor activity when compared to either drug alone.
Niraparib exhibits a dose-proportional increase in Cmax and AUC in the dose range of 30-400 mg. Abiraterone demonstrates no major deviation for dose proportionality observed in the dose range of 250-1,000 mg. The bioavailability of niraparib is approximately73%, reaching maximum concentration at 3 hours.
Abiraterone reaches maximum concentration at 1.5 hours. Administration of abiraterone with food results in up to a 10-fold increase in AUC and up to a 17-fold increase in systemicexposurecompared to the fasted state depending on fat content of the meal; administration with food has the potential to result in increased and highly variable exposure. Niraparib is 83% bound to human plasma proteins.
Abiraterone is >99% bound to human plasma proteins (primarily albumin and alpha-1 acid glycoprotein). Niraparib is metabolized by carboxylesterases and has a half-life of approximately 62 hours, after which 48% (range: 33-60%) is recovered in urine and 39% (range: 28-47%) in feces; unchanged niraparib accounts for 11% and 19% of theadministered dose recovered in urine and feces, respectively. Abiraterone acetate is rapidly converted to abiraterone and is subsequently metabolized by cytochrome P450 (CYP) 3A4 and sulfotransferase family 2A member 1 (SULT2A1).
Abiraterone has a half-life of approximately 20 hours. Abiraterone is recovered in feces (88%) and in urine (5%); unchanged abiraterone acetate and abiraterone account for 55% and 22% of administered dose recovered in the feces, respectively. No clinically significant effects on the pharmacokinetics of niraparib or abiraterone are observed based on body weight, age, race/ethnicity, and mild to moderate renal impairment (creatinine clearance 30-90 mL/minute).
Severe renal impairment (creatinine clearance 15-30 mL/minute) has not been studied. Mild hepatic impairment (Child-Pugh class A) has no effect on niraparib exposure but increases abiraterone AUC by 1.1-fold. Moderate hepatic impairment (Child-Pugh class B) increases niraparib AUC by 56% and increases abiraterone AUC by 3.6-fold.
Severe hepatic impairment (Child-Pugh class C) increases abiraterone AUC by 7-fold and fraction of free drug by 2-fold.
USES: This combination medication is used to treat prostate cancer. It contains 2 medications: niraparib and abiraterone. Niraparib works by slowing the growth of cancer cells.
Abiraterone works by decreasing the amount of testosterone the body makes, which helps slow down the growth and spread of prostate cancer.
Generic name: niraparib tosylate/abiraterone acetate
Drug class: Antineoplastic-Poly (ADP-Ribose) polymerase (PARP) inhibitor
Therapeutic class: Antineoplastics
Reference product & biosimilars
No reference, biosimilar or interchangeable associated with this drug.
Today’s intelligence on Akeega
Indications
The following indications are listed for Akeega:
- Metastatic Castration-Resistant Prostate Cancer With Brca Mutation
- Metastatic Castration-Sensitive Prostate Cancer With Brca2 Mutation
Also known as: Brca-Mutated Mcrpc, Brca2 -Mutated Mcspc, Mcr Prostate Cancer With Brca Mutation, Mcs Prostate Cancer With Brca2 Mutation.
Dosing
For adverse reactions, consider interruption of treatment, dosage reduction, or discontinuation. Treatment with niraparib/abiraterone should not be reinitiated until the toxicity has resolved to grade 1 or baseline. If the toxicity is attributed to one component of niraparib/abiraterone, the other component may be continued as a single agent at the current dose until the adverse reaction resolves and niraparib/abiraterone can be resumed.
Niraparib/abiraterone tabletsshould be taken orallyon an empty stomach. Patients should not eat for 2 hours before and 1 hour after taking niraparib/abiraterone. Tablets should be swallowed whole with water. Do not break, crush, or chew tablets.
If a patient misses a dose, instruct them to take the dose as soon as possible on the same day and resume their next dose at the normal schedule the following day.
Store tablets at 20-25degreesC; excursions permitted to 15-30degreesC.
| Drug label | Dosing type | Instructions |
|---|---|---|
| Akeega 50-500 Mg Tablet | Maintenance | Take 2 tablets by oral route once daily. |
| Akeega 100-500 Mg Tablet | Maintenance | Take 2 tablets by oral route once daily. |
No dosing information is available for this tab.
Drug interactions
Niraparib is metabolized by carboxylesterases. In vitro, niraparib is not an inhibitor of cytochrome P450 (CYP) 1A2, 2B6, 2C8, 2C9, 2C19, 2D6, and 3A4. Niraparib is not an inducer of CYP3A4 but is an in vitro inducer of CYP1A2. Niraparib does not inhibit uridine-diphosphate glucuronosyltransferases (UGT) 1A1, 1A4, 1A9, or 2B7. Niraparib is a substrate of breast cancer resistance protein (BRCP) and P-glycoprotein (P-gp). In vitro, niraparib inhibits BRCP and multidrug and toxic compound extrusion (MATE) 1 and 2. Niraparib does not inhibit P-gp, bile salt export pump (BSEP), or multidrug resistance-associated protein (MRP) 2.
Abiraterone acetate is rapidly converted to abiraterone and is subsequently metabolized by CYP3A4 and sulfotransferase family 2A member 1 (SULT2A1). In vitro, abiraterone is a substrate of CYP3A4 and has the potential to inhibit CYP1A2, 2D6, 2C8, and to a lesser extent CYP2C9, 2C19, 3A4/5. Abiraterone acetate and abiraterone are not substrates of P-gp. Abiraterone acetate is a P-gp inhibitor in vitro. In vitro, abiraterone and its major metabolites are inhibitors of organic anion transporter polypeptide (OATP) 1B1.
Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.
Abiraterone/Radium Ra 223
SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.
MECHANISM OF ACTION: The mechanism of this interaction is not known.
CLINICAL EFFECTS: Concurrent use of radium Ra 223 dichloride with abiraterone and prednisolone, prednisone, or methylprednisolone may increase the risk of mortality and fractures.(1-4)
PREDISPOSING FACTORS: None determined.
PATIENT MANAGEMENT: The European Medicines Agency (EMA) states that the use of radium Ra 223 with abiraterone and prednisone/prednisolone is contraindicated. Radium Ra 223 is not recommended to be initiated in the first 5 days following the last dose of abiraterone and prednisone/prednisolone.(2,5) The US manufacturers of radium Ra 223 and abiraterone state that radium Ra 223 is not recommended for use in combination with abiraterone and prednisone/prednisolone or methylprednisolone outside of clinical trials.(3,4) Monitor patients for fractures.
DISCUSSION: In the ERA 223 trial, a randomized, double-blind, placebo-controlled trial of 806 patients with castration-resistant prostate cancer with bone metastasis, treatment with abiraterone and prednisone/prednisolone plus radium Ra 223 was associated with increased incidences of fractures and deaths (28.6% and 38.5%, respectively), compared to treatment with abiraterone and prednisone/prednisolone plus placebo (11.4% and 35.5%, respectively).(6)
Abiraterone/Strong Cyp3a4 Inducers
SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.
MECHANISM OF ACTION: Strong inducers of CYP3A4 may induce the metabolism of abiraterone.(1)
CLINICAL EFFECTS: Concurrent or recent use of a strong inducer of CYP3A4 may result in decreased levels and effectiveness of abiraterone.(1)
PREDISPOSING FACTORS: Induction effects may be more likely with regular use of the inducer for longer than 1-2 weeks.
PATIENT MANAGEMENT: Avoid concurrent use of strong inducers of CYP3A4 with abiraterone.(1) Consider the use of agents with no or minimal induction potential if possible. Monitor patients for decreased response to therapy. If concurrent administration of abiraterone and a strong CYP3A4 inducers is required, increase the dosing frequency of abiraterone from once daily to twice daily during the co-administration period. If the strong inducer is discontinued, reduce the dose of abiraterone back to the previous dose and frequency.(1)
DISCUSSION: In a drug interaction trial, concurrent administration of rifampin, a strong CYP3A4 inducer, decreased abiraterone levels by 55%.(1) Strong inducers of CYP3A4 include: apalutamide, barbiturates, carbamazepine, encorafenib, enzalutamide, fosphenytoin, ivosidenib, lumacaftor, mitotane, phenobarbital, phenytoin, primidone, rifampin, rifapentine, and St. John's wort.(2,3)
Abiraterone; Cabazitaxel; Vincristine/Rifabutin
SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.
MECHANISM OF ACTION: Rifabutin is an inducer of CYP3A4 and may increase the metabolism of abiraterone,(1) cabazitaxel,(2,3) and vincristine.(4)
CLINICAL EFFECTS: Concurrent or recent use of rifabutin may result in decreased levels and effectiveness of abiraterone,(1) cabazitaxel,(3) and vincristine.(4)
PREDISPOSING FACTORS: None determined.
PATIENT MANAGEMENT: Avoid concurrent use of rifabutin with abiraterone,(1) cabazitaxel,(3) and vincristine.(4) Consider the use of agents with no or minimal induction potential if possible. Monitor patients for decreased response to therapy. If concurrent administration of abiraterone and rifabutin is required, increase the dosing frequency of abiraterone from once daily to twice daily during the co-administration period. If rifabutin is discontinued, reduce the dose of abiraterone back to the previous dose and frequency.(1)
DISCUSSION: Abiraterone,(1) cabazitaxel,(2,3) and vincristine (3) are metabolized by CYP3A4. Strong inducers of this isoenzyme are expected to decrease levels of these agents. The US manufacturers of abiraterone(1) and vincristine(4) and the UK manufacturer of cabazitaxel(3) include rifabutin on the list of strong CYP3A4 inducers that should be avoided. In a drug interaction trial, concurrent administration of rifampin, a strong CYP3A4 inducer, decreased abiraterone levels by 55%.(1) In a study in 21 advanced cancer patients, rifampin (600mg) decreased the exposure to cabazitaxel (15mg/m2) by 17%.(2)
Immunosuppressive; Immunomod/Cladribine Onc Inj (10 Mg/5 Ml)
SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.
MECHANISM OF ACTION: Cladribine in combination with immunosuppressives and immune-modulators all suppress the immune system.(1-2)
CLINICAL EFFECTS: Concurrent use of cladribine with immunosuppressive or immune-modulating agents may result in an increased risk of serious infections.(1-2)
PREDISPOSING FACTORS: Incomplete washout of previously prescribed immunosuppressive or immune-modulating medications.
PATIENT MANAGEMENT: Recommendations for cladribine regarding this interaction differ between regulatory approving agencies. The UK and AU manufacturers of Litak state that concomitant use of other myelosuppressive medicinal products with cladribine is contraindicated.(1-2) The Israeli manufacturer of Litak states that cladribine should not be used concomitantly with other myelosuppressive medicinal products.(3)
DISCUSSION: The risk of severe myelotoxicity and long-lasting immunosuppression is increased in patients with a disease-related bone marrow infiltration or a previous myelosuppressive treatment.(1-3)
Immunosuppressives; Immunomodulators/Efalizumab; Natalizumab
SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.
MECHANISM OF ACTION: Natalizumab,(1-3) efalizumab,(4) immunosuppressives, and immunomodulators all suppress the immune system.
CLINICAL EFFECTS: Concurrent use of natalizumab(1-3) or efalizumab(4) with immunosuppressives or immunomodulators may result in an increased risk of infections, including progressive multifocal leukoencephalopathy (PML), an opportunistic infection caused by the JC virus (JCV).
PREDISPOSING FACTORS: Previous JCV infection, longer duration of natalizumab treatment - especially if greater than 2 years, and prior or concomitant treatment with immunosuppressant medication are all independent risk factors which increase the risk for PML.(1,5) The FDA has estimated PML incidence stratified by risk factors: If anti-JCV antibody positive, no prior immunosuppressant use and natalizumab treatment less than 25 months, incidence <1/1,000. If anti-JCV antibody positive, history of prior immunosuppressant use and natalizumab treatment less than 25 months, incidence 2/1,000 If anti-JCV antibody positive, no prior immunosuppressant use and natalizumab treatment 25-48 months, incidence 4/1,000 If anti-JCV antibody positive, history of prior immunosuppressant use and natalizumab treatment 25-48 months, incidence 11/1,000.
PATIENT MANAGEMENT: The US manufacturer of natalizumab states patients with Crohn's disease should not receive concurrent immunosuppressants, with the exception of limited overlap of corticosteroids, due to the increased risk for PML. For new natalizumab patients currently receiving chronic oral corticosteroids for Crohn's Disease, begin corticosteroid taper when therapeutic response to natalizumab has occurred. If corticosteroids cannot be discontinued within six months of starting natalizumab, discontinue natalizumab.(3) The US manufacturer of natalizumab states that natalizumab should not ordinarily be used in multiple sclerosis patients receiving immunosuppressants or immunomodulators due to the increased risk for PML. Immunosuppressives include, but are not limited to azathioprine, cyclophosphamide, cyclosporine, mercaptopurine, methotrexate, mitoxantrone, mycophenolate, and corticosteroids.(3,6) The UK manufacturer of natalizumab states that concurrent use with immunosuppressives or antineoplastic agents is contraindicated.(1) The Canadian manufacturer of natalizumab states that natalizumab should not be used with immunosuppressive or immunomodulatory agents.(2) The US manufacturer of certolizumab states that concurrent therapy with natalizumab is not recommended.(7)
DISCUSSION: Progressive multifocal leukoencephalopathy has been reported in patients receiving concurrent natalizumab were recently or concomitantly taking immunomodulators or immunosuppressants.(1-5,8,9) In a retrospective cohort study of multiple sclerosis patients newly initiated on a disease-modifying therapy, use of high-efficacy agents (alemtuzumab, natalizumab, or ocrelizumab) resulted in the same risk of overall infections as moderate-efficacy agents, but there was an elevated risk of serious infections (adjusted hazard ratio [aHR] = 1.24, 95% confidence interval (CI) = 1.06-1.44) and UTIs (aHR = 1.21, 95% CI = 1.14-1.30).(10)
Selected Immunosuppressants/Nadofaragene Firadenovec
SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.
MECHANISM OF ACTION: Nadofaragene firadenovec may contain low levels of replication-competent adenovirus.(1)
CLINICAL EFFECTS: Concurrent use of nadofaragene firadenovec in patients receiving immunosuppressive therapy may cause disseminated adenovirus infection.(1)
PREDISPOSING FACTORS: None determined.
PATIENT MANAGEMENT: Individuals who are immunosuppressed or immune-deficient should not receive nadofaragene firadenovec.(1)
DISCUSSION: Nadofaragene firadenovec is a non-replicating adenoviral vector-based gene therapy but may contain low levels of replication-competent adenovirus. Immunocompromised persons, including those receiving immunosuppressant therapy, may be at risk for disseminated adenovirus infection.(1)
Selected Immunosuppressants/Talimogene Laherparepvec
SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.
MECHANISM OF ACTION: Talimogene laherparepvec is a live, attenuated herpes simplex virus.(1)
CLINICAL EFFECTS: Concurrent use of talimogene laherparepvec in patients receiving immunosuppressive therapy may cause a life-threatening disseminated herpetic infection.(1)
PREDISPOSING FACTORS: None determined.
PATIENT MANAGEMENT: Talimogene laherparepvec is contraindicated in immunosuppressed patients.(1) The magnitude of immunocompromise and associated risks due to immunosuppressant drugs should be determined by a physician.
DISCUSSION: Concurrent use of talimogene laherparepvec in patients receiving immunosuppressive therapy may cause a life-threatening disseminated herpetic infection.(1)
Selected Immunosuppressive Agents/Live Vaccines; Live Bcg
SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.
MECHANISM OF ACTION: A variety of disease modifying agents suppress the immune system. Immunocompromised patients may be at increased risk for uninhibited replication after administration of live, attenuated vaccines or intravesicular BCG. Immune response to vaccines may be decreased during periods of immunocompromise.(1)
CLINICAL EFFECTS: The expected serum antibody response may not be obtained and/or the vaccine may result in illness.(1) After instillation of intravesicular BCG, immunosuppression may interfere with local immune response, or increase the severity of mycobacterial infection following inadvertent systemic exposure.(2)
PREDISPOSING FACTORS: Immunosuppressive diseases (e.g. hematologic malignancies, HIV disease), treatments (e.g. radiation) and drugs may all increase the magnitude of immunodeficiency.
PATIENT MANAGEMENT: The Centers for Disease Control(CDC) Advisory Committee on Immunization Practices (ACIP) states that live-virus and live, attenuated vaccines should not be administered to patients who are immunocompromised. The magnitude of immunocompromise and associated risks should be determined by a physician.(1) For patients scheduled to receive chemotherapy, vaccination should ideally precede the initiation of chemotherapy by 14 days. Patients vaccinated while on immunosuppressive therapy or in the 2 weeks prior to starting therapy should be considered unimmunized and should be revaccinated at least 3 months after discontinuation of therapy.(1) Patients who receive anti-B cell therapies should not receive live vaccines for at least 6 months after such therapies due to a prolonged duration of immunosuppression. An exception is the Zoster vaccine, which can be given at least 1 month after receipt of anti-B cell therapies.(1) The US manufacturer of abatacept states live vaccines should not be given during or for up to 3 months after discontinuation of abatacept.(2) The US manufacturer of live BCG for intravesicular treatment of bladder cancer states use is contraindicated in immunosuppressed patients.(3) The US manufacturer of daclizumab states live vaccines are not recommended during and for up to 4 months after discontinuation of treatment.(4) The US manufacturer of guselkumab states that live vaccines should be avoided during treatment with guselkumab.(5) The US manufacturer of inebilizumab-cdon states that live vaccines are not recommended during treatment and after discontinuation until B-cell repletion. Administer all live vaccinations at least 4 weeks prior to initiation of inebilizumab-cdon.(6) The US manufacturer of ocrelizumab states that live vaccines are not recommended during treatment and until B-cell repletion occurs after discontinuation of therapy. Administer all live vaccines at least 4 weeks prior to initiation of ocrelizumab.(7) The US manufacturer of ozanimod states that live vaccines should be avoided during and for up to 3 months after discontinuation of ozanimod.(8) The US manufacturer of siponimod states that live vaccines are not recommended during treatment and for up to 4 weeks after discontinuation of treatment.(9) The US manufacturer of ustekinumab states BCG vaccines should not be given in the year prior to, during, or the year after ustekinumab therapy.(10) The US manufacturer of satralizumab-mwge states that live vaccines are not recommended during treatment and should be administered at least four weeks prior to initiation of satralizumab-mwge.(11) The US manufacturer of ublituximab-xiiy states that live vaccines are not recommended during treatment and until B-cell recovery. Live vaccines should be administered at least 4 weeks prior to initiation of ublituximab-xiiy.(12) The US manufacturer of etrasimod states that live vaccines should be avoided during and for 5 weeks after treatment. Live vaccines should be administered at least 4 weeks prior to initiation of etrasimod.(13) The US manufacturer of emapalumab-lzsg states that live vaccines should not be administered to patients receiving emapalumab-lzsg and for at least 4 weeks after the last dose of emapalumab-lzsg. The safety of immunization with live vaccines during or following emapalumab-lzsg therapy has not been studied.(14) The US manufacturer of sibeprenlimab-szsi states live vaccines should not be given within 30 days prior to initiation or during treatment with sibeprenlimab-szsi.(15)
DISCUSSION: Killed or inactivated vaccines do not pose a danger to immunocompromised patients.(1) Patients with a history of leukemia who are in remission and have not received chemotherapy for at least 3 months are not considered to be immunocompromised.(1)
Severe Interaction: Action is required to reduce the risk of severe adverse interaction.
Abiraterone/Pioglitazone; Repaglinide
SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.
MECHANISM OF ACTION: The mechanism of interaction is not fully understood but may at least partially involve CYP2C8 inhibition by abiraterone, resulting in decreased metabolism of pioglitazone and repaglinide.(1,2)
CLINICAL EFFECTS: Concurrent use of pioglitazone or repaglinide with abiraterone may result in elevated levels and clinical effects of the anti-diabetic agents, including severe hypoglycemia.(1)
PREDISPOSING FACTORS: None determined.
PATIENT MANAGEMENT: Monitor blood glucose in patients with diabetes during and after discontinuation of treatment with abiraterone. Consider dosage adjustment of pioglitazone or repaglinide to minimize the risk of hypoglycemia.(1)
DISCUSSION: Severe hypoglycemia has been reported in diabetic patients receiving pioglitazone or repaglinide concurrently with abiraterone. A review of the FDA Adverse Events Reporting database found 2 reports of hypoglycemia in patients receiving concurrent abiraterone and repaglinide. One patient was hospitalized with life-threatening outcomes, and the other died, though he also had sepsis and cardiac failure. In a study of 16 healthy volunteers, single-dose abiraterone 1,000 mg increased the maximum concentration (Cmax) and area-under-curve (AUC) of single-dose pioglitazone 15 mg by 23% and 46%.(3)
Abiraterone/Spironolactone
SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.
MECHANISM OF ACTION: When used in an androgen-deprived environment created by abiraterone, spironolactone binds to the androgen receptor and acts as an androgen agonist.
CLINICAL EFFECTS: Spironolactone may increase prostate-specific antigen (PSA) levels in metastatic prostate cancer patients on abiraterone.
PREDISPOSING FACTORS: None determined.
PATIENT MANAGEMENT: Concurrent use of spironolactone and abiraterone is not recommended.
DISCUSSION: In a case report, a 67-year-old man with metastatic castration-resistant prostate cancer (mCRPC) on abiraterone for 6 months with good response started spironolactone for heart failure. His PSA rose from 0.004 ng/mL prior to starting spironolactone to 0.93 ng/mL. After spironolactone discontinuation, PSA dropped to 0.38 ng/mL, but subsequently rose again due to disease progression.(3) A 67-year-old man on spironolactone 25 mg daily and a history of prostate cancer experienced bone progression and a rise in PSA. He was started on abiraterone 1,000 mg daily and prednisone 5 mg twice daily, but PSA continued to rise 5 months after starting abiraterone.(3) In a case report, an 86-year-old man on abiraterone for mCRPC started spironolactone and experienced biochemical and radiologic disease progression with PSA rising from 278.7 ng/mL to 792.7 ng/mL. After spironolactone was discontinued, PSA dropped to 334.2 ng/mL.(4) A 57-year-old man with mCRPC on spironolactone failed to respond to abiraterone and prednisone, with PSA rising from 5.97 ng/mL to 8.08 ng/mL. Spironolactone was discontinued and PSA dropped to 2.8 ng/mL after 2 weeks and 0.45 ng/mL after 2 months. After 10 months on abiraterone, the patient experienced disease progression and was switched to enzalutamide. Eight months later, his PSA rose slightly to 0.2 ng/mL. He revealed that he had been taking spironolactone for 3 weeks. Spironolactone was stopped and PSA dropped to 0.14 ng/mL.(5)
Abiraterone/Thioridazine
SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.
MECHANISM OF ACTION: Abiraterone may inhibit the metabolism of thioridazine by CYP2D6.(1)
CLINICAL EFFECTS: Concurrent use of abiraterone may result in elevated levels of and toxicity from thioridazine, including potentially life-threatening cardiac arrhythmias such as torsades de pointes.(1)
PREDISPOSING FACTORS: Patients who are CYP2D6 ultrarapid metabolizers may be affected to a greater extent by CYP2D6 inhibitors. Patients who are CYP2D6 poor metabolizers lack CYP2D6 function and are not affected by CYP2D6 inhibition. The risk of QT prolongation or torsade de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2) The risk of anticholinergic toxicities including cognitive decline, delirium, falls and fractures is increased in geriatric patients using more than one medicine with anticholinergic properties.(3)
PATIENT MANAGEMENT: The US manufacturer of abiraterone states that concurrent use of CYP2D6 substrates with narrow therapeutic indexes such as thioridazine should be avoided. If concurrent use is warranted, consider decreasing the dose of thioridazine.(1) Additionally, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting.
DISCUSSION: Concurrent abiraterone increased the area-under-curve (AUC) and maximum concentration (Cmax) of dextromethorphan (another CYP2D6 substrate) by 2.9-fold and 2.8-fold, respectively.(1)
Immunosuppres;Immunomodul/Selected Multiple Sclerosis Agents
SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.
MECHANISM OF ACTION: Ocrelizumab or ofatumumab in combination with immunosuppressives and immune-modulators all suppress the immune system.(1,2)
CLINICAL EFFECTS: Concurrent use of ocrelizumab or ofatumumab with immunosuppressive or immune-modulating agents may result in an increased risk of serious infections, such as disseminated herpetic infection or progressive multifocal leukoencephalopathy (PML), an opportunistic infection caused by the JC virus (JCV).(1,2)
PREDISPOSING FACTORS: Incomplete washout of previously prescribed immunosuppressive or immune-modulating medications.
PATIENT MANAGEMENT: The ocrelizumab US prescribing information states: - Ocrelizumab and other immune-modulating or immunosuppressive therapies, (including immunosuppressant doses of corticosteroids) are expected to increase the risk of immunosuppression, and the risk of additive immune system effects must be considered if these therapies are coadministered with ocrelizumab. When switching from drugs with prolonged immune effects, such as daclizumab, fingolimod, natalizumab, teriflunomide, or mitoxantrone, the duration and mode of action of these drugs must be considered to avoid unintended additive immunosuppressive effects when initiating ocrelizumab.(1) The ofatumumab US prescribing information states: - Ofatumumab and other immunosuppressive therapies (including systemic corticosteroids) may have the potential for increased immunosuppressive effects and increase the risk of infection. When switching between therapies, the duration and mechanism of action of each therapy should be considered due to the potential for additive immunosuppressive effects. Ofatumumab for MS therapy has not been studied in combination with other MS agents that suppress the immune system.(2)
DISCUSSION: Fatal disseminated herpes zoster and herpes simplex infections and cases of progressive multifocal leukoencephalopathy (PML) have been reported in patients who previously received immunomodulators or immunosuppressants.(1,2) In a retrospective cohort study of multiple sclerosis patients newly initiated on a disease-modifying therapy, use of high-efficacy agents (alemtuzumab, natalizumab, or ocrelizumab) resulted in the same risk of overall infections as moderate-efficacy agents, but there was an elevated risk of serious infections (adjusted hazard ratio [aHR] = 1.24, 95% confidence interval (CI) = 1.06-1.44) and UTIs (aHR = 1.21, 95% CI = 1.14-1.30).(3)
Immunosuppressives; Immunomodulators/Baricitinib
SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.
MECHANISM OF ACTION: Concurrent use of baricitinib with other biologic disease-modifying antirheumatic drugs (DMARDs) or potent immunosuppressants such as azathioprine or cyclosporine may result in additive or synergistic effects on the immune system.
CLINICAL EFFECTS: Concurrent use of baricitinib with other biologic DMARDs or potent immunosuppressants such as azathioprine or cyclosporine may increase the risk of serious infections.(1)
PREDISPOSING FACTORS: None determined.
PATIENT MANAGEMENT: The US manufacturer of baricitinib states that concurrent use of baricitinib with biologic DMARDs or potent immunosuppressants is not recommended.(1)
DISCUSSION: Most patients who developed serious infections while being treated with baricitinib were on concomitant immunosuppressants like methotrexate and corticosteroids. The combination of baricitinib with other biologic DMARDs has not been studied.(1)
Immunosuppressives; Immunomodulators/Cladribine Oral
SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.
MECHANISM OF ACTION: Cladribine in combination with immunosuppressives and immune-modulators all suppress the immune system.(1-2)
CLINICAL EFFECTS: Concurrent use of cladribine with immunosuppressive or immune-modulating agents may result in an increased risk of serious infections, such as disseminated herpetic infection or progressive multifocal leukoencephalopathy (PML), an opportunistic infection caused by the JC virus (JCV).(1-2)
PREDISPOSING FACTORS: Incomplete washout of previously prescribed immunosuppressive or immune-modulating medications.
PATIENT MANAGEMENT: Recommendations for cladribine regarding this interaction differ between regulatory approving agencies. The cladribine US prescribing information states: -Concomitant use with myelosuppressive or other immunosuppressive drugs is not recommended. Acute short-term therapy with corticosteroids can be administered. In patients who have previously been treated with immunomodulatory or immunosuppressive drugs, consider potential additive effect, the mode of action, and duration of effect of the other drugs prior to initiation of cladribine.(1) The cladribine Canadian prescribing information states: -Use of cladribine in immunocompromised patients is contraindicated because of a risk of additive effects on the immune system. Acute short-term therapy with corticosteroids can be administered during cladribine treatment.(2)
DISCUSSION: Fatal disseminated herpes zoster and herpes simplex infections and cases of progressive multifocal leukoencephalopathy (PML) have been reported in patients who previously received immunomodulators or immunosuppressants.(1-2)
Immunosuppressives; Immunomodulators/Deuruxolitinib
SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.
MECHANISM OF ACTION: Deuruxolitinib, immunosuppressives, and immunomodulators all suppress the immune system.(1)
CLINICAL EFFECTS: Concurrent use of deuruxolitinib and potent immunosuppressants may increase the risk of serious infections.(1)
PREDISPOSING FACTORS: None determined.
PATIENT MANAGEMENT: The US manufacturer of deuruxolitinib states that concurrent use of deuruxolitinib with other JAK inhibitors, biologic immunomodulators, cyclosporine or other potent immunosuppressants is not recommended.(1) If concurrent use cannot be avoided, patients should be monitored for signs and symptoms of infection. If a patient develops a serious or opportunistic infection, interrupt deuruxolitinib treatment until the infection is controlled.
DISCUSSION: Serious infections have been reported in patients receiving treatment with deuruxolitinib.(1)
Immunosuppressives; Immunomodulators/Etrasimod
SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.
MECHANISM OF ACTION: Etrasimod causes reversible sequestration of lymphocytes in lymphoid tissues, resulting in a mean 55% decrease in peripheral blood lymphocyte count at 52 weeks.(1) Other immunosuppressives and immune-modulators also suppress the immune system.
CLINICAL EFFECTS: Concurrent use of etrasimod with immunosuppressive or immune-modulating agents may result in an increased risk of serious and fatal infections, such as disseminated herpetic infection, cryptococcal infection, or progressive multifocal leukoencephalopathy (PML).(1)
PREDISPOSING FACTORS: Incomplete washout of previously prescribed immunosuppressive or immune-modulating medications increases the risk of adverse effects.
PATIENT MANAGEMENT: The etrasimod US prescribing information states etrasimod has not been studied in combination with anti-neoplastic, immune-modulating, or immunosuppressive therapies. Concomitant administration of these therapies with etrasimod should be avoided because of the risk of additive immune effects during therapy and in the weeks following administration. Etrasimod's effect on peripheral lymphocytes may persist for up to 5 weeks after discontinuation.(1) When switching from drugs with prolonged immune effects, the half-life and mode of action of these drugs must be considered in order to avoid unintended additive immunosuppressive effects.(1)
DISCUSSION: Fatal disseminated herpes zoster and herpes simplex infections, cryptococcal meningitis, disseminated cryptococcal infections, and cases of progressive multifocal leukoencephalopathy (PML) have been reported in patients treated with other sphingosine-1 phosphate receptor modulators.(1)
Immunosuppressives; Immunomodulators/Filgotinib
SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.
MECHANISM OF ACTION: Concurrent use of filgotinib with other immunosuppressants or immunomodulators including azathioprine, cyclosporine, tacrolimus, biologic disease-modifying antirheumatic drugs (DMARDs), or other Janus kinase (JAK) inhibitors may result in additive or synergistic effects on the immune system.(1)
CLINICAL EFFECTS: Concurrent use of filgotinib with other immunosuppressants or immunomodulators including azathioprine, cyclosporine, tacrolimus, biologic DMARDs, or other JAK inhibitors may increase the risk of serious infections.(1)
PREDISPOSING FACTORS: None determined.
PATIENT MANAGEMENT: The UK manufacturer of filgotinib states that concurrent use of filgotinib with other immunosuppressants or immunomodulators including azathioprine, cyclosporine, tacrolimus, biologic DMARDs, or other JAK inhibitors is not recommended.(1)
DISCUSSION: Serious infections have been reported in patients receiving filgotinib. Caution should be used in patients with a higher incidence of serious infection, including elderly patients aged 75 years and older.(1)
Immunosuppressives; Immunomodulators/Fingolimod
SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.
MECHANISM OF ACTION: Fingolimod in combination with immunosuppressives and immune-modulators all suppress the immune system.(1-3)
CLINICAL EFFECTS: Concurrent use of fingolimod with immunosuppressive or immune-modulating agents may result in an increased risk of serious infections, such as disseminated herpetic infection or progressive multifocal leukoencephalopathy (PML), an opportunistic infection caused by the JC virus (JCV).(1-3)
PREDISPOSING FACTORS: Incomplete washout of previously prescribed immunosuppressive or immune-modulating medications.
PATIENT MANAGEMENT: Recommendations for fingolimod regarding this interaction differ between regulatory approving agencies. The fingolimod US prescribing information states: - Antineoplastic, immune-modulating, or immunosuppressive therapies, (including corticosteroids) are expected to increase the risk of immunosuppression, and the risk of additive immune system effects must be considered if these therapies are coadministered with fingolimod. When switching from drugs with prolonged immune effects, such as natalizumab, teriflunomide or mitoxantrone, the duration and mode of action of these drugs must be considered to avoid unintended additive immunosuppressive effects when initiating fingolimod.(1) The fingolimod Canadian prescribing information states: - Concurrent use with immunosuppressive or immunomodulatory agents is contraindicated due to the risk of additive immune system effects. However, co-administration of a short course of corticosteroids (up to 5 days) did not increase the overall rate of infection in patients participating Phase III clinical trials.(2) The fingolimod UK specific product characteristics states: - Fingolimod is contraindicated in patients currently receiving immunosuppressive therapies or those immunocompromised by prior therapies. When switching patients from another disease modifying therapy to Gilenya, the half-life and mode of action of the other therapy must be considered in order to avoid an additive immune effect whilst at the same time minimizing the risk of disease activation.(3)
DISCUSSION: Fatal disseminated herpes zoster and herpes simplex infections and cases of progressive multifocal leukoencephalopathy (PML) have been reported in patients who previously received immunomodulators or immunosuppressants.(1-3)
Immunosuppressives; Immunomodulators/Inebilizumab
SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.
MECHANISM OF ACTION: Inebilizumab, immunosuppressives, and immunomodulators all suppress the immune system.(1)
CLINICAL EFFECTS: Concurrent use of inebilizumab with immunosuppressive or immunomodulating agents may result in myelosuppression including neutropenia resulting in an increased risk for serious infections.(1)
PREDISPOSING FACTORS: None determined.
PATIENT MANAGEMENT: The US manufacturer of inebilizumab states that the concurrent use of inebilizumab with immunosuppressive agents, including systemic corticosteroids, may increase the risk of infection. If concurrent therapy is warranted, consider the risk of additive immune suppression and monitor based on prescribing information for both agents.(1)
DISCUSSION: Inebilizumab has not been studied in combination with other immunosuppressants. If concurrent therapy is warranted, consider the potential for increased immunosuppressive risks from both agents. The most common infections reported by inebilizumab treated patients in the randomized and open-label clinical trial periods included urinary tract infections (20%), nasopharyngitis (13%), upper respiratory tract infections (8%), and influenza (7%). Although there been no cases of Hepatitis B virus reactivation or progressive multifocal leukoencephalopathy reported in patients taking inebilizumab, these infections have been observed in patients taking other B-cell-depleting antibodies.(1)
Immunosuppressives; Immunomodulators/Ozanimod
SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.
MECHANISM OF ACTION: Ozanimod in combination with immunosuppressives and immune-modulators all suppress the immune system.(1)
CLINICAL EFFECTS: Concurrent use of ozanimod with immunosuppressive or immune-modulating agents may result in an increased risk of serious infections, such as disseminated herpetic infection or progressive multifocal leukoencephalopathy (PML), an opportunistic infection caused by the JC virus (JCV).(1)
PREDISPOSING FACTORS: Incomplete washout of previously prescribed immunosuppressive or immune-modulating medications.
PATIENT MANAGEMENT: The ozanimod US prescribing information state this information regarding this interaction: -Ozanimod has not been studied in combination with anti-neoplastic, immune-modulating, or immunosuppressive therapies. Caution should be used during concomitant administration because of the risk of additive immune effects during therapy and in the week following administration. When switching from drugs with prolonged immune effects, the half-life and mode of action of these drugs must be considered in order to avoid unintended additive immunosuppressive effects. Initiating treatment with ozanimod after alemtuzumab is not recommended. However, ozanimod can generally be started immediately after discontinuation of beta interferon or glatiramer acetate.(1)
DISCUSSION: Fatal disseminated herpes zoster and herpes simplex infections and cases of progressive multifocal leukoencephalopathy (PML) have been reported in patients who previously received immunomodulators or immunosuppressants.(1)
Immunosuppressives; Immunomodulators/Ponesimod
SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.
MECHANISM OF ACTION: Ponesimod in combination with immunosuppressives and immune-modulators all suppress the immune system.(1)
CLINICAL EFFECTS: Concurrent use of ponesimod with immunosuppressive or immune-modulating agents may result in an increased risk of serious infections, such as disseminated herpetic infection, cryptococcal infection, or progressive multifocal leukoencephalopathy (PML), an opportunistic infection caused by the JC virus (JCV).(1)
PREDISPOSING FACTORS: Incomplete washout of previously prescribed immunosuppressive or immune-modulating medications.
PATIENT MANAGEMENT: The ponesimod US prescribing information states ponesimod has not been studied in combination with anti-neoplastic, immune-modulating, or immunosuppressive therapies. Caution should be used during concomitant administration because of the risk of additive immune effects during therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, the half-life and mode of action of these drugs must be considered in order to avoid unintended additive immunosuppressive effects. Initiating treatment with ponesimod after alemtuzumab is not recommended. However, ponesimod can generally be started immediately after discontinuation of beta interferon or glatiramer acetate.(1)
DISCUSSION: Fatal disseminated herpes zoster and herpes simplex infections, cryptococcal meningitis, disseminated cryptococcal infections, and cases of progressive multifocal leukoencephalopathy (PML) have been reported in patients who previously received immunomodulators or immunosuppressants.(1)
Immunosuppressives; Immunomodulators/Ritlecitinib
SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.
MECHANISM OF ACTION: Ritlecitinib, immunosuppressives, and immunomodulators all suppress the immune system.
CLINICAL EFFECTS: Concurrent use of ritlecitinib with immunosuppressives or immunomodulators may result in an increased risk of serious infections.
PREDISPOSING FACTORS: None determined.
PATIENT MANAGEMENT: The US manufacturer of ritlecitinib states that concurrent use of ritlecitinib with other JAK inhibitors, biologic immunomodulators, cyclosporine or other potent immunosuppressants is not recommended.(1)
DISCUSSION: Serious infections have been reported in patients receiving ritlecitinib. Reported infections included appendicitis, COVID-19 infection (including pneumonia), and sepsis. Reports of viral reactivation, including herpes virus reactivation was reported in clinical studies with ritlecitinib.(1)
Immunosuppressives; Immunomodulators/Siponimod
SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.
MECHANISM OF ACTION: Siponimod in combination with immunosuppressives and immune-modulators all suppress the immune system.(1)
CLINICAL EFFECTS: Concurrent use of siponimod with immunosuppressive or immune-modulating agents may result in an increased risk of serious infections, such as disseminated herpetic infection or progressive multifocal leukoencephalopathy (PML), an opportunistic infection caused by the JC virus (JCV).(1)
PREDISPOSING FACTORS: Incomplete washout of previously prescribed immunosuppressive or immune-modulating medications.
PATIENT MANAGEMENT: The siponimod US prescribing information state this information regarding this interaction: -Siponimod has not been studied in combination with anti-neoplastic, immune-modulating, or immunosuppressive therapies. Caution should be used during concomitant administration because of the risk of additive immune effects during therapy and in the week following administration. When switching from drugs with prolonged immune effects, the half-life and mode of action of these drugs must be considered in order to avoid unintended additive immunosuppressive effects. Initiating treatment with siponimod after alemtuzumab is not recommended. However, siponimod can generally be started immediately after discontinuation of beta interferon or glatiramer acetate.(1)
DISCUSSION: Fatal disseminated herpes zoster and herpes simplex infections and cases of progressive multifocal leukoencephalopathy (PML) have been reported in patients who previously received immunomodulators or immunosuppressants.(1)
Immunosuppressives; Immunomodulators/Tofacitinib
SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.
MECHANISM OF ACTION: Concurrent use of tofacitinib and azathioprine, other biologic disease-modifying antirheumatic drugs (DMARDs), or potent immunosuppressants may result in additive or synergistic effects on the immune system.(1)
CLINICAL EFFECTS: Concurrent use of tofacitinib and azathioprine, other biologic DMARDs, or potent immunosuppressants use may increase the risk of serious infections.(1)
PREDISPOSING FACTORS: None determined.
PATIENT MANAGEMENT: Tofacitinib should not be used concurrently with azathioprine, other biologic DMARDs, or cyclosporine.(1) Patient should be monitored for decreases in lymphocytes and neutrophils. Therapy should be adjusted based on the indication. - For all indications: If absolute neutrophil count (ANC) or lymphocyte count is less than 500 cells/mm3, discontinue tofacitinib. - For rheumatoid arthritis or psoriatic arthritis and absolute neutrophil count (ANC) 500 to 1000 cells/mm3: interrupt dosing. When ANC is greater than 1000 cells/mm3, resume Xeljanz 5 mg twice daily or Xeljanz XR 11 mg once daily. - For ulcerative colitis and ANC 500 to 1000 cells/mm3: -If taking Xeljanz 10 mg twice daily, decrease to 5 mg twice daily. When ANC is greater than 1000 cells/mm3, increase to 10 mg twice daily based on clinical response. -If taking Xeljanz 5 mg twice daily, interrupt dosing. When ANC is greater than 1000 cells/mm3, resume 5 mg twice daily. -If taking Xeljanz XR 22 mg once daily, decrease to 11 mg once daily. When ANC is greater than 1000 cells/mm3, increase to 22 mg once daily based on clinical response. -If taking Xeljanz XR 11 mg once daily, interrupt dosing. When ANC is greater than 1000 cells/mm3, resume 11 mg once daily. - For polyarticular course juvenile idiopathic arthritis (pcJIA) and ANC 500 to 1000 cells/mm3: interrupt dosing until ANC is greater than 1000 cells/mm3.(1)
DISCUSSION: Concurrent use of tofacitinib and azathioprine, other biologic DMARDs, or potent immunosuppressants may increase the risk of infection.(1) Serious infections due to bacterial, mycobacterial, invasive fungal, viral, or other opportunistic pathogens have been reported in patients receiving tofacitinib. Some patients presented with disseminated disease and were often taking concomitant immunomodulating agents. In the ulcerative colitis population, a greater risk of serious infections was seen with a higher tofacitinib dose. In 7 placebo-controlled rheumatoid arthritis trials (0-3 months exposure), the overall frequency of infections was 20% in the tofacitinib 5 mg twice daily group and 22% in the tofacitinib 10 mg twice daily group compared to 18% in the placebo group. Serious infections were reported in 11 patients (1.7 events per 100 patient-years) with a rate difference between treatment groups of 1.1 (-0.4, 2.5) events per 100 patient-years for both tofacitinib 5 mg twice daily and 10 mg twice daily. During 0-12 months exposure, serious infections were reported in 34 patients (2.7 events per 100 patient years) in the tofacitinib 5 mg twice daily group and 33 patients (2.7 events per 100 patient years) in the tofacitinib 10 mg twice daily group.(1)
Immunosuppressives; Immunomodulators/Upadacitinib
SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.
MECHANISM OF ACTION: Upadacitinib, immunosuppressives, and immunomodulators all suppress the immune system.
CLINICAL EFFECTS: Concurrent use of upadacitinib with immunosuppressives or immunomodulators may result in an increased risk of serious infections.
PREDISPOSING FACTORS: None determined.
PATIENT MANAGEMENT: The US manufacturer of upadacitinib states that concurrent use of upadacitinib with immunosuppressives or immunomodulators is not recommended.
DISCUSSION: Serious infections have been reported in patients receiving upadacitinib. Reported infections included pneumonia, cellulitis, tuberculosis, multidermatomal herpes zoster, oral/esophageal candidiasis, cryptococcosis. Reports of viral reactivation, including herpes virus reactivation and hepatitis B reactivation, were reported in clinical studies with upadacitinib.(1)
Myelosuppressives; Immunomodulators/Sodium Iodide I 131
SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.
MECHANISM OF ACTION: Sodium iodide I 131 can cause depression of the hematopoetic system. Myelosuppressives and immunomodulators also suppress the immune system.(1)
CLINICAL EFFECTS: Concurrent use of sodium iodide I 131 with agents that cause bone marrow depression, including myelosuppressives or immunomodulators, may result in an enhanced risk of hematologic disorders, including anemia, blood dyscrasias, bone marrow depression, leukopenia, and thrombocytopenia. Bone marrow depression may increase the risk of serious infections and bleeding.(1)
PREDISPOSING FACTORS: None determined.
PATIENT MANAGEMENT: The US manufacturer of sodium iodide I 131 states that concurrent use with bone marrow depressants may enhance the depression of the hematopoetic system caused by large doses of sodium iodide I 131.(1) Sodium iodide I 131 causes a dose-dependent bone marrow suppression, including neutropenia or thrombocytopenia, in the 3 to 5 weeks following administration. Patients may be at increased risk of infections or bleeding during this time. Monitor complete blood counts within one month of therapy. If results indicate leukopenia or thrombocytopenia, dosimetry should be used to determine a safe sodium iodide I 131 activity.(1)
DISCUSSION: Hematologic disorders including death have been reported with sodium iodide I 131. The most common hematologic disorders reported include anemia, blood dyscrasias, bone marrow depression, leukopenia, and thrombocytopenia.(1)
Selected Immunosuppressants/Leflunomide; Teriflunomide
SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.
MECHANISM OF ACTION: Concurrent use of leflunomide or teriflunomide and potent immunosuppressants may result in additive or synergistic effects on the immune system.(1,2) Leflunomide is a prodrug and is converted to its active metabolite teriflunomide.(1)
CLINICAL EFFECTS: Concurrent use of leflunomide or teriflunomide with immunosuppressants may result in an increased risk of serious infections, including opportunistic infections, especially Pneumocystis jiroveci pneumonia, tuberculosis (including extra-pulmonary tuberculosis), and aspergillosis.
PREDISPOSING FACTORS: None determined.
PATIENT MANAGEMENT: If leflunomide or teriflunomide is used concurrently with immunosuppressive agents, chronic CBC monitoring should be performed more frequently, every month instead of every 6 to 8 weeks. If bone marrow suppression or a serious infection occurs, leflunomide or teriflunomide should be stopped and rapid drug elimination procedure should be performed.(1,2)
DISCUSSION: Pancytopenia, agranulocytosis and thrombocytopenia have been reported in patients receiving leflunomide or teriflunomide alone, but most frequently in patients taking concurrent immunosuppressants.(1,2) Severe and potentially fatal infections, including sepsis, have been reported in patients receiving leflunomide or teriflunomide, especially Pneumocystis jiroveci pneumonia and aspergillosis. Tuberculosis has also been reported.(1,2)
Selected Moderate Cyp2d6 Inhibitors/Tamoxifen
SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.
MECHANISM OF ACTION: Inhibitors of CYP2D6 may inhibit the conversion of tamoxifen to endoxifen (an active metabolite of tamoxifen).(1-2) The role of endoxifen in tamoxifen's efficacy has been debated and may involve a minimum concentration level.(3-5)
CLINICAL EFFECTS: Concurrent use of inhibitors of CYP2D6 may decrease the effectiveness of tamoxifen in preventing breast cancer recurrence.
PREDISPOSING FACTORS: Concurrent use of moderate CYP2D6 inhibitors in patients who are CYP2D6 ultrarapid, normal, or intermediate metabolizers should be avoided. Patients who are CYP2D6 poor metabolizers lack CYP2D6 function and are not affected by CYP2D6 inhibition.
PATIENT MANAGEMENT: Although data on this interaction are conflicting, it may be prudent to use alternatives to CYP2D6 inhibitors when possible in patients taking tamoxifen. The US manufacturer of tamoxifen states that the impact on the efficacy of tamoxifen by strong CYP2D6 inhibitors is uncertain and makes no recommendation regarding coadministration with inhibitors of CYP2D6.(12) The manufacturer of paroxetine (a strong CYP2D6 inhibitor) states that alternative agents with little or no CYP2D6 inhibition should be considered.(13) The National Comprehensive Cancer Network's breast cancer guidelines advises caution when coadministering strong CYP2D6 inhibitors with tamoxifen.(14) NCCN states when prescribing a selective serotonin reuptake inhibitor (SSRI), it is reasonable to avoid SSRIs that are strong and moderate CYP2D6 inhibitors, particularly fluoxetine and paroxetine, if an appropriate alternative exists.(14) Cancer Care Ontario breast cancer guidelines state concurrent use of moderate CYP2D6 inhibitors should be approached with caution and alternative options should be considered.(15) The European Society of Medical Oncology (ESMO) clinical practice guidelines for early breast cancer states patients on tamoxifen should be advised to avoid concurrent use of strong and moderate CYP2D6 inhibitors. Consider alternatives to tamoxifen if CYP2D6 inhibitors cannot be replaced with alternative agents.(16) If concurrent therapy is warranted, the risks versus benefits should be discussed with the patient. Rolapitant, a moderate CYP2D6 inhibitor, effects on CYP2D6 are expected to last at least 28 days after administration.(17)
DISCUSSION: Some studies have suggested that administration of fluoxetine, paroxetine, and quinidine with tamoxifen or a CYP2D6 poor metabolizer phenotype may result in a decrease in the formation of endoxifen (an active metabolite of tamoxifen) and a shorter time to breast cancer recurrence.(1-2,9) A retrospective study of 630 breast cancer patients found an increasing risk of breast cancer mortality with increasing durations of coadministration of tamoxifen and paroxetine. In the adjusted analysis, absolute increases of 25%, 50%, and 75% in the proportion of time of overlapping use of tamoxifen with paroxetine was associated with 24%, 54%, and 91% increase in the risk of death from breast cancer, respectively.(18) The CYP2D6 genotype of the patient may have a role in the effects of this interaction. Patients with wild-type CYP2D6 genotype may be affected to a greater extent by this interaction. Patients with a variant CYP2D6 genotype may have lower baseline levels of endoxifen and may be affected to a lesser extent by this interaction.(6-10) In a retrospective review, 1,325 patients treated with tamoxifen for breast cancer were classified as being poor 2D6 metabolizers (lacking functional CYP2D6 enzymes), intermediate metabolizers (heterozygous alleles), or extensive metabolizers (possessing 2 functional alleles). After a mean follow-up period of 6.3 years, the recurrence rates were 14.9%, 20.9%, and 29.0%, in extensive metabolizers, intermediate metabolizers, and poor metabolizers, respectively.(11) In October of 2006, the Advisory Committee Pharmaceutical Science, Clinical Pharmacology Subcommittee of the US Food and Drug Administration recommended that the US tamoxifen labeling be updated to include information about the increased risk of breast cancer recurrence in poor CYP2D6 metabolizers (either by genotype or drug interaction).(19-20) The labeling changes were never made due to ongoing uncertainty about the effects of CYP2D6 genotypes on tamoxifen efficacy. In contrast to the above information, two studies have shown no relationship between CYP2D6 genotype and breast cancer outcome.(21-23) As well, a number of studies found no association between use of CYP2D6 inhibitors and/or antidepressants in patients on tamoxifen and breast cancer recurrence,(24-28) though the studies were limited by problematic selection of CYP2D6 inhibitors and short follow-up. A single dose of rolapitant increased dextromethorphan, a CYP2D6 substrate, about 3-fold on days 8 and day 22 following administration. Dextromethorphan levels remained elevated by 2.3-fold on day 28 after single dose rolapitant. The inhibitory effects of rolapitant on CYP2D6 are expected to persist beyond 28 days.(17) Moderate inhibitors of CYP2D6 include abiraterone, asunaprevir, berotralstat, capivasertib, cinacalcet, duloxetine, eliglustat, levomepromazine, mirabegron, moclobemide, rolapitant, and tipranavir/ritonavir.(29-30)
Selected Myelosuppressive Agents/Clozapine
SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.
MECHANISM OF ACTION: Clozapine and other myelosuppressive agents may be associated with neutropenia or agranulocytosis.(2)
CLINICAL EFFECTS: Moderate neutropenia, even if due to combination therapy, may require abrupt discontinuation of clozapine resulting in decompensation of the patient's psychiatric disorder (e.g. schizophrenia). The disease treated by the myelosuppressive agent may be compromised if myelosuppression requires dose reduction, delay, or discontinuation of the myelosuppressive agent. Undetected severe neutropenia or agranulocytosis may be fatal.
PREDISPOSING FACTORS: Low white blood counts prior to initiation of the myelosuppressive agent may increase risk for clinically significant neutropenia.
PATIENT MANAGEMENT: If a patient stabilized on clozapine therapy requires treatment with a myelosuppressive agent, the clozapine prescriber should consult with prescriber of the myelosuppressive agent (e.g. oncologist) to discuss treatment and monitoring options.(2) More frequent absolute neutrophil count (ANC) monitoring or treatment alternatives secondary to neutropenic episodes may need to be considered. The U.S. Food and Drug Administration (FDA) recommends that prescribers monitor patients' ANC according to the monitoring frequencies described in the prescribing information. Severe neutropenia remains a serious, potentially fatal risk that is greatest in the first several months of clozapine treatment. ANC monitoring can help identify neutropenia early to allow for timely intervention.(1-2) Australia, Canada, and U.K.: Clozapine is only available through a restricted distribution system which requires documentation of the ANC prior to dispensing. For most clozapine patients, clozapine treatment must be interrupted for a suspected clozapine-induced ANC < 1000 cells/microliter. For patients with benign ethnic neutropenia (BEN), treatment must be interrupted for suspected clozapine-induced neutropenia < 500 cells/microliter.(2)
DISCUSSION: Concurrent use of clozapine and selected myelosuppressive agents may require more frequent ANC monitoring or consideration of treatment alternatives secondary to neutropenic episodes. Agents linked to this interaction generally have > 5% risk for neutropenia and/or warnings describing risk for myelosuppression in manufacturer prescribing information.(3-26)
Selected Myelosuppressive Agents/Deferiprone
SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.
MECHANISM OF ACTION: Concurrent use of deferiprone with other drugs known to be associated with neutropenia or agranulocytosis may increase the frequency or risk for severe toxicity.(1)
CLINICAL EFFECTS: Concurrent use of deferiprone and myelosuppressive agents may result in severe neutropenia or agranulocytosis, which may be fatal.
PREDISPOSING FACTORS: Agranulocytosis may be less common in patients receiving deferiprone for thalassemia, and more common in patients treated for other systemic iron overload conditions (e.g. myelodysplastic syndromes, sickle cell disease).(2,3) Inadequate monitoring appears to increase the risk for severe outcomes. Manufacturer post market surveillance found that in all fatal cases of agranulocytosis reported between 1999 and 2005, data on weekly white blood count (WBC) monitoring was missing. In three fatal cases, deferiprone was continued for two to seven days after the detection of neutropenia or agranulocytosis.(2)
PATIENT MANAGEMENT: If possible, discontinue one of the drugs associated with risk for neutropenia or agranulocytosis. If alternative therapy is not available, documentation and adherence to the deferiprone monitoring protocol is essential. Baseline absolute neutrophil count (ANC) must be at least 1,500/uL prior to starting deferiprone. Monitor ANC weekly during therapy. If infection develops, interrupt deferiprone therapy and monitor ANC more frequently. If ANC is less than 1,500/uL but greater than 500/uL, discontinue deferiprone and any other drugs possibly associated with neutropenia. Initiate ANC and platelet counts daily until recovery (i.e. ANC at least 1,500/uL). If ANC is less than 500/uL, discontinue deferiprone, evaluate patient and hospitalize if appropriate. Do not resume deferiprone unless potential benefits outweigh potential risks.(1)
DISCUSSION: Drugs linked to this monograph have an FDA Boxed Warning for risk of neutropenia, agranulocytosis, or pancytopenia, or have > 5% risk for neutropenia and/or warnings describing risk for myelosuppression in manufacturer prescribing information.(1-25) In pooled clinical studies submitted to the FDA, 6.1% of deferiprone patients met criteria for neutropenia and 1.7% of patients developed agranulocytosis.(1) The time to onset of agranulocytosis was highly variable with a range of 65 days to 9.2 years (median, 161 days).(3)
Selected Myelosuppressive Agents/Dipyrone
SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.
MECHANISM OF ACTION: Concurrent use of dipyrone with other drugs known to be associated with neutropenia or agranulocytosis may increase the frequency or risk for severe toxicity.(1-29)
CLINICAL EFFECTS: Concurrent use of dipyrone with agents that cause bone marrow depression, including myelosuppressives, may result in an enhanced risk of hematologic disorders, including anemia, blood dyscrasias, bone marrow depression, leukopenia, and thrombocytopenia. Bone marrow depression may increase the risk of serious infections and bleeding. Undetected severe neutropenia or agranulocytosis may be fatal.(1-29)
PREDISPOSING FACTORS: None determined.
PATIENT MANAGEMENT: Concurrent use of dipyrone and myelosuppressive agents should be avoided. The European Medicines Agency states dipyrone is contraindicated in patients with a prior medical history of dipyrone-induced agranulocytosis (or from other pyrazolones/pyrazolidines), impaired bone marrow function or diseases of the hematopoietic system.(3) International labeling for dipyrone and methotrexate state that co-administration may increase the hematotoxicity of methotrexate, especially in elderly patients, and therefore should be avoided.(1-2) The European Medicines Agency advises if agranulocytosis is suspected with dipyrone, a complete blood count (including differential blood count) should be performed immediately, and treatment must be stopped while waiting for the results. If confirmed, treatment must not be reintroduced.(1-3)
DISCUSSION: A retrospective cohort study analyzed new users of dipyrone (n=444,972), non-steroidal anti-inflammatory drugs (n=3,814,367) which served as a reference cohort, and opioids-paracetamol (n=3,129,221) which was the negative control. During continuous treatment over a median of 37-40 days, 26 cases of hospitalized agranulocytosis occurred. With the assumption that agranulocytosis onset was 7 days prior to admission, the hazard ratio of agranulocytosis associated with dipyrone was 4.40 [0.90-21.57] compared to NSAIDs and 2.45 [0.68-8.83] compared to opioid-paracetamol. HR of neutropenia from dipyrone was 2.98 [1.57-5.65] compared to NSAIDs and not statistically significant compared to opioids-paracetamol. In a sensitivity analysis assuming that the onset of agranulocytosis was the date of hospitalization, the HR of dipyrone-induced agranulocytosis was 7.20 [95% confidence interval: 1.92-26.99] compared to NSAIDs and 3.31 [1.17-9.34] compared to opioids-paracetamol. Agranulocytosis was very rare but more than 4 times more common with dipyrone than other analgesics.(4) In a review of 1,448 reports of agranulocytosis attributed to dipyrone, patients with fatal outcomes were older and more often had also received methotrexate compared to those with non-fatal outcomes (odds ratio: 5.18; 95% confidence interval: 3.06-8.78).(5) Agents linked to this interaction generally have > 5% risk for neutropenia and/or warnings describing risk for myelosuppression in manufacturer prescribing information.(2,6-26)
Slt Immunosuppress; Immunomodulator/Ropeginterferon Alfa-2B
SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.
MECHANISM OF ACTION: Ropeginterferon alfa-2b and immunosuppressives both suppress the immune system.
CLINICAL EFFECTS: Concurrent use of ropeginterferon alfa-2b with immunosuppressives may result in an increased risk of serious infections.
PREDISPOSING FACTORS: None determined.
PATIENT MANAGEMENT: Avoid concurrent use of myelosuppressive agents.(1-2) If concurrent use cannot be avoided, monitor for effects of excessive immunosuppression.
DISCUSSION: In clinical trials, 20% of patients experienced leukopenia. Interferon alfa products may cause fatal or life-threatening infections.(1-2)
Strong & Moderate Cyp2d6 Inhibitors/Eliglustat
SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.
MECHANISM OF ACTION: Strong inhibitors of CYP2D6 may inhibit the metabolism of eliglustat. If the patient is also taking an inhibitor of CYP3A4, eliglustat metabolism can be further inhibited.(1)
CLINICAL EFFECTS: Concurrent use of an agent that is a strong or moderate inhibitor of CYP2D6 may result in elevated levels of and clinical effects of eliglustat, including prolongation of the PR, QTc, and/or QRS intervals, which may result in life-threatening cardiac arrhythmias.(1)
PREDISPOSING FACTORS: If the patient has hepatic impairment, is also taking an inhibitor of CYP3A4 and/or is an extensive or intermediate metabolizer of CYP2D6, eliglustat metabolism can be further inhibited.(1) The risk of QT prolongation or torsades de pointes may be increased in patients with cardiovascular disease (e.g. heart failure, myocardial infarction, history of torsades de pointes, congenital long QT syndrome), hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, female gender, or advanced age.(2) Concurrent use of more than one drug known to cause QT prolongation or higher systemic concentrations of either QT prolonging drug are additional risk factors for torsades de pointes. Factors which may increase systemic drug concentrations include rapid infusion of an intravenous dose or impaired metabolism or elimination of the drug (e.g. coadministration with an agent which inhibits its metabolism or elimination, genetic impairment in drug metabolism or elimination, and/or renal/hepatic dysfunction).(2)
PATIENT MANAGEMENT: The dosage of eliglustat with strong or moderate inhibitors of CYP2D6 in both extensive and intermediate CYP2D6 metabolizers should be limited to 84 mg daily.(1) The dosage of eliglustat with strong or moderate inhibitors of CYP2D6 in poor CYP2D6 metabolizers should be continued at 84 mg once daily.(1) The concurrent use of eliglustat with strong inhibitors of CYP3A4 concomitantly with strong or moderate inhibitors of CYP2D6 is contraindicated.(1) The concurrent use of eliglustat with moderate inhibitors of CYP3A4 concomitantly with strong or moderate inhibitors of CYP2D6 in poor metabolizers of CYP2D6 should be avoided and is contraindicated in extensive and intermediate metabolizers of CYP2D6.(1) If concurrent therapy is warranted, consider obtaining serum calcium, magnesium, and potassium levels and monitoring ECG at baseline and at regular intervals. Correct any electrolyte abnormalities. Instruct patients to report any irregular heartbeat, dizziness, or fainting. Rolapitant, a moderate CYP2D6 inhibitor, effects on CYP2D6 are expected to last at least 28 days after administration.(5)
DISCUSSION: Paroxetine (30 mg daily), a strong inhibitor of CYP2D6, increased eliglustat (84 mg BID) maximum concentration (Cmax) and area-under-curve (AUC) by 7-fold and 8.4-fold, respectively, in extensive metabolizers. Physiologically-based pharmacokinetic (PKPB) models suggested paroxetine would increase eliglustat Cmax and AUC by 2.1-fold and 2.3-fold, respectively, in intermediate metabolizers. PKPB models suggested ketoconazole may increase the Cmax and AUC of eliglustat (84 mg daily) by 4.3-fold and 6.2-fold, respectively, in poor metabolizers.(1) PKPB models suggested terbinafine, a moderate inhibitor of CYP2D6, would increase eliglustat Cmax and AUC by 3.8-fold and 4.5-fold, respectively, in extensive metabolizers and by 1.6-fold and 1.6-fold, respectively in intermediate metabolizers. PKPB models suggest that concurrent eliglustat (84 mg BID), paroxetine (a strong inhibitor of CYP2D6), and ketoconazole would increase eliglustat Cmax and AUC by 16.7-fold and 24.2-fold, respectively, in extensive metabolizers. In intermediate metabolizers, eliglustat Cmax and AUC would be expected to increase 7.5-fold and 9.8-fold, respectively.(1) PKPB models suggest that concurrent eliglustat (84 mg BID), terbinafine (a moderate inhibitor of CYP2D6), and ketoconazole would increase eliglustat Cmax and AUC by 10.2-fold and 13.6-fold, respectively, in extensive metabolizers. In intermediate metabolizers, eliglustat Cmax and AUC would be expected to increase 4.2-fold and 5-fold, respectively.(1) A single dose of rolapitant increased dextromethorphan, a CYP2D6 substrate, about 3-fold on days 8 and day 22 following administration. Dextromethorphan levels remained elevated by 2.3-fold on day 28 after single dose rolapitant. The inhibitory effects of rolapitant on CYP2D6 are expected to persist beyond 28 days.(5) Strong inhibitors of CYP2D6 include: bupropion, dacomitinib, fluoxetine, hydroquinidine, paroxetine, quinidine, and terbinafine.(1,3,4) Moderate inhibitors of CYP2D6 include: abiraterone, asunaprevir, capivasertib, cinacalcet, duloxetine, escitalopram, levomepromazine, levomethadone, mirabegron, moclobemide, and rolapitant.(1,3,4)
Moderate Interaction: Assess the risk to the patient and take action as needed.
Immunosuppressives; Immunomodulators/Cladribine Oncology Inj
SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.
MECHANISM OF ACTION: Cladribine in combination with immunosuppressives and immune-modulators all suppress the immune system.(1-4)
CLINICAL EFFECTS: Concurrent use of cladribine with immunosuppressive or immune-modulating agents may result in an increased risk of serious infections.(1-4)
PREDISPOSING FACTORS: Incomplete washout of previously prescribed immunosuppressive or immune-modulating medications.
PATIENT MANAGEMENT: Recommendations for cladribine regarding this interaction differ between regulatory approving agencies. The cladribine US, UK, and Australian prescribing information state: -Caution should be exercised if cladribine injection is administered before, after, or in conjunction with other drugs known to cause immunosuppression or myelosuppression.(1-3) The cladribine Canadian prescribing information states: -Proceed carefully in patients with severe bone marrow impairment of any etiology since further suppression of bone marrow function should be anticipated.(4)
DISCUSSION: Severe bone marrow suppression, including neutropenia, anemia and thrombocytopenia, has been commonly observed in patients treated with cladribine injection, especially at high doses.(1-4)
Immunosuppressives; Immunomodulators/Covid-19 Vaccines
SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.
MECHANISM OF ACTION: Immunosuppressants and immunomodulators may prevent the immune system from properly responding to the COVID-19 vaccine.(1-3)
CLINICAL EFFECTS: Administration of a COVID-19 vaccine with immunosuppressants or immunomodulators may interfere with vaccine-induced immune response and impair the efficacy of the vaccine. However, patients should be offered and given a COVID-19 vaccine even if the use and timing of immunosuppressive agents cannot be adjusted.(1-3)
PREDISPOSING FACTORS: None determined.
PATIENT MANAGEMENT: The Centers for Disease Control and Prevention (CDC),(1) Infectious Diseases Society of America (IDSA),(2) and the American College of Rheumatology (ACR)(3) have published guidances for COVID-19 vaccination in patients on immunosuppressants. The CDC states that all immunocompromised patients over 6 months of age should receive at least 1 dose of COVID-19 vaccine if eligible. See the CDC's Interim Clinical Considerations for Use of COVID-19 Vaccines for specific recommendations based on age, vaccination history, and vaccine manufacturer.(1) The CDC advises planning for vaccination at least 2 weeks before starting or resuming immunosuppressive therapy.(1) IDSA recommends timing COVID-19 vaccination at least 2 weeks before starting or at least 3 months after completing immunosuppressive therapy.(2) The ACR states that in general, immunosuppressants and immunomodulators should be held for 1-2 weeks after each vaccine dose.(3) Patients should be offered and given a COVID-19 vaccine even if the use and timing of immunosuppressive agents cannot be adjusted, though the immune response will likely be blunted. COVID-19 vaccines should not be delayed in patients taking immunosuppressive therapies.(1-2) See below for specific recommendations for certain agents. B-cell depleting agents, including rituximab: The CDC states that the utility of B-cell quantification to guide clinical care is not known and is not recommended. Patients who receive B-cell depleting therapy on a continuing basis should receive COVID-19 vaccines about 4 weeks before the next scheduled dose. For patients who received 1 or more doses of COVID-19 vaccine during treatment with B-cell-depleting therapies that were administered over a limited period (e.g., as part of a treatment regimen for certain malignancies), revaccination may be considered according to the current CDC recommendations for unvaccinated patients. The suggested interval to start revaccination is about 6 months after completion of the B-cell-depleting therapy.(1) IDSA recommends waiting for at least 3-6 months after the last infusion of B-cell depleting therapy before administering COVID-19 vaccines.(2) The ACR recommends consulting with the rheumatologist to determine optimal timing of COVID-19 vaccination. Measuring CD19 B cells may be considered to determine need for a booster vaccine dose. If B cell levels are not measured, a supplemental vaccine dose 2-4 weeks before the next scheduled dose of rituximab is recommended.(3) Recipients of hematopoietic cell transplant or CAR-T-cell therapy who received one or more doses of COVID-19 vaccine prior to or during treatment should undergo revaccination following the current CDC recommendations for unvaccinated patients. Revaccination should start at least 3 months (12 weeks) after transplant or CAR-T-cell therapy.(1,2) The CDC includes abatacept, cyclophosphamide, and TNF-alpha and cytokine inhibitors in their general recommendation to hold therapy for at least 2 weeks following vaccination (1) while the ACR provides different recommendations:(3) *Abatacept: - Subcutaneous abatacept should be withheld for 1-2 weeks after each vaccine dose, as disease activity allows. - For intravenous abatacept, time administration so that vaccination will occur 1 week before the next abatacept infusion. *Cyclophosphamide: When feasible, administer cyclophosphamide 1 week after each COVID-19 vaccine dose. *TNF-alpha inhibitors and cytokine inhibitors: The ACR was not able to reach consensus on whether to modify dosing or timing of these agents with COVID-19 vaccination.
DISCUSSION: IDSA recommendations are based on cohort and case control studies in immunocompromised patients that found low to modest vaccine effectiveness (37-61%) but lower risks of COVID-19 association hospitalization, COVID-19 related mortality, and critical illness.(2) The ACR convened a COVID-19 Vaccine Guidance Task Force to provide guidance on optimal use of COVID-19 vaccines in rheumatology patients. These recommendations are based on limited clinical evidence of COVID-19 vaccines in patients without rheumatic and musculoskeletal disorders and evidence of other vaccines in this patient population.(3) The ACR recommendation for rituximab is based on studies of humoral immunity following receipt of other vaccines. These studies have uncertain generalizability to vaccination against COVID-19, as it is unknown if efficacy is attributable to induction of host T cells versus B cell (antibody-based) immunity.(3) The ACR recommendation for mycophenolate is based on preexisting data of mycophenolate on non-COVID-19 vaccine immunogenicity. Emerging data suggests that mycophenolate may impair SARS-CoV-2 vaccine response in rheumatic and musculoskeletal disease and transplant patients.(3) The ACR recommendation for methotrexate is based on data from influenza vaccines and pneumococcal vaccines with methotrexate.(3) The ACR recommendation for JAK inhibitors is based on concerns related to the effects of JAK inhibitors on interferon signaling that may result in a diminished vaccine response.(3) The ACR recommendation for subcutaneous abatacept is based on several studies suggesting a negative effect of abatacept on vaccine immunogenicity. The first vaccine dose primes naive T cells, naive T cell priming is inhibited by CTLA-4, and abatacept is a CTLA-4Ig construct. CTLA-4 should not inhibit boosts of already primed T cells at the time of the second vaccine dose.(3)
Immunosuppressives; Immunomodulators/Sarilumab
SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.
MECHANISM OF ACTION: Sarilumab, immunosuppressives, and immunomodulators all suppress the immune system.(1)
CLINICAL EFFECTS: Concurrent use of sarilumab with immunosuppressive or immunomodulating agents may result in an increased risk for serious infections.(1)
PREDISPOSING FACTORS: None determined.
PATIENT MANAGEMENT: The US manufacturer of sarilumab recommends caution because the concurrent use of sarilumab with immunosuppressive agents may increase the risk of infection. If concurrent therapy is warranted, consider the risk of additive immune suppression and monitor based on prescribing information for both agents.(1)
DISCUSSION: Sarilumab was studied as monotherapy and in combination with methotrexate or conventional disease modifying antirheumatic drugs (DMARDs) in rheumatoid arthritis studies. Sarilumab has not been studied with biological DMARDs and concurrent use should be avoided. If concurrent therapy is warranted, consider the potential for increased immunosuppressive risks from both agents.(1) The most common infections reported by sarilumab treated patients in the clinical trial periods included pneumonia and cellulitis. Serious bacterial, mycobacterial, fungal, and viral infections were observed in patients receiving sarilumab. Cases of tuberculosis, candidiasis, and pneumocystis with sarilumab have been reported.(1)
Immunosuppressives; Immunomodulators/Tocilizumab
SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.
MECHANISM OF ACTION: Tocilizumab, immunosuppressives, and immunomodulators all suppress the immune system.(1)
CLINICAL EFFECTS: Concurrent use of tocilizumab with immunosuppressive or immunomodulating agents may result in an increased risk for serious infections.(1)
PREDISPOSING FACTORS: None determined.
PATIENT MANAGEMENT: The US manufacturer of tocilizumab recommends caution because the concurrent use of tocilizumab with immunosuppressive agents may increase the risk of infection. If concurrent therapy is warranted, consider the risk of additive immune suppression and monitor based on prescribing information for both agents.(1)
DISCUSSION: Tocilizumab was studied as monotherapy and in combination with methotrexate, non-biologic DMARDs or corticosteroids, depending on the indication. Tocilizumab has not been studied with biological DMARDs and concurrent use should be avoided. If concurrent therapy is warranted, consider the potential for increased immunosuppressive risks from both agents.(1) The most common infections reported by tocilizumab treated patients in the clinical trial periods included pneumonia, urinary tract infection, cellulitis, herpes zoster, gastroenteritis, diverticulitis, sepsis and bacterial arthritis. Serious bacterial, mycobacterial, fungal, and viral infections were observed in patients receiving tocilizumab. Cases of tuberculosis, cryptococcus, aspergillosis, candidiasis, and pneumocystosis have been reported.(1)
Immunosuppressives; Immunomodulators/Ublituximab
SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.
MECHANISM OF ACTION: Ublituximab, immunosuppressives, and immunomodulators all suppress the immune system.(1)
CLINICAL EFFECTS: Concurrent use of ublituximab with immunosuppressive or immunomodulating agents may result in an increased risk for serious infections.(1)
PREDISPOSING FACTORS: Incomplete washout of previously prescribed immunosuppressive or immune-modulating medications.
PATIENT MANAGEMENT: The US manufacturer of ublituximab recommends caution because the concurrent use of ublituximab with immunomodulating or immunosuppressive agents, including immunosuppressant doses of corticosteroids, may increase the risk of infection.(1) If concurrent therapy is warranted, consider the risk of additive immune suppression and monitor based on prescribing information for both agents. When switching from agents with immune effects, the half-life and mechanism of action of these drugs must be taken into consideration in order to prevent additive immunosuppressive effects.(1)
DISCUSSION: The most common infections reported by ublituximab-treated patients in the clinical trial periods included upper respiratory tract infections and urinary tract infections. Serious, including life-threatening or fatal, bacterial and viral infections were observed in patients receiving ublituximab.(1) Serious and/or fatal bacterial, fungal, and new or reactivated viral infections have been associated with other anti-CD20 B-cell depleting therapies. There were no cases of progressive multifocal leukoencephalopathy (PML) reported during the clinical trials; however, there have been reports of PML during or following completion of other anti-CD20 B-cell depleting therapies.(1)
Immunosuppressives; Immunomodulators/Ustekinumab
SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.
MECHANISM OF ACTION: Ustekinumab, immunosuppressives, and immunomodulators all suppress the immune system.(1)
CLINICAL EFFECTS: Concurrent use of ustekinumab with immunosuppressive or immunomodulating agents may result in an increased risk for serious infections.(1)
PREDISPOSING FACTORS: None determined.
PATIENT MANAGEMENT: The US manufacturer of ustekinumab recommends caution because the concurrent use of ustekinumab with immunosuppressive agents may increase the risk of infection. If concurrent therapy is warranted, consider the risk of additive immune suppression and monitor based on prescribing information for both agents.(1)
DISCUSSION: Ustekinumab has not been studied in combination with other immunosuppressants in psoriasis studies. In psoriatic arthritis studies, concomitant methotrexate use did not appear to influence the safety or efficacy of ustekinumab. In Crohn's disease and ulcerative colitis studies, concomitant use of immunosuppressants or corticosteroids did not appear to influence the safety or efficacy of ustekinumab. If concurrent therapy is warranted, consider the potential for increased immunosuppressive risks from both agents.(1) The most common infections reported by ustekinumab treated patients in the clinical trial periods included nasopharyngitis(8%) and upper respiratory tract infection(5%). Serious bacterial, mycobacterial, fungal, and viral infections were observed in patients receiving ustekinumab. Cases of interstitial pneumonia, eosinophilic pneumonia, and cryptogenic organizing pneumonia resulting in respiratory failure or prolonged hospitalization have been reported in patients receiving ustekinumab.(1)
Moderate Cyp2d6 Inhibitors/Brexpiprazole
SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.
MECHANISM OF ACTION: CYP2D6 inhibitors may inhibit the metabolism of brexpiprazole.(1)
CLINICAL EFFECTS: Concurrent administration of a moderate CYP2D6 inhibitor may result in elevated levels of and toxicity from brexpiprazole.(1)
PREDISPOSING FACTORS: This interaction is expected to be more severe in patients who are receiving concomitant treatment with a strong or moderate CYP3A4 inhibitor in addition to treatment with a CYP2D6 inhibitor. Concurrent use of strong CYP2D6 and CYP3A4 inhibitors is expected to increase brexpiprazole levels 5.1-fold in extensive metabolizers of CYP2D6.(1)
PATIENT MANAGEMENT: The US manufacturer of brexpiprazole recommends the following dose adjustments for patients who are receiving a moderate CYP2D6 inhibitor: - in patients with schizophrenia or major depressive disorder who are taking a moderate CYP2D6 inhibitor AND who are receiving a strong or moderate inhibitor of CYP3A4, decrease the dose to one-fourth the usual dose. - no empiric dosage adjustment is recommended for patients receiving moderate CYP2D6 inhibitors without a strong or moderate inhibitor of CYP3A4. The dose of brexpiprazole should be adjusted to its original level if the CYP2D6 inhibitor is discontinued.(1) Rolapitant, a moderate CYP2D6 inhibitor, effects on CYP2D6 are expected to last at least 28 days after administration.(2)
DISCUSSION: Coadministration of quinidine, a strong inhibitor of CYP2D6, increased the area-under-curve (AUC) of brexpiprazole approximately 2-fold.(1) A single dose of rolapitant increased dextromethorphan, a CYP2D6 substrate, about 3-fold on days 8 and day 22 following administration. Dextromethorphan levels remained elevated by 2.3-fold on day 28 after single dose rolapitant. The inhibitory effects of rolapitant on CYP2D6 are expected to persist beyond 28 days.(2) Moderate CYP2D6 inhibitors linked to this monograph include: abiraterone, asunaprevir, capivasertib, cinacalcet, duloxetine, eliglustat, escitalopram, levomepromazine, mirabegron, moclobemide, and rolapitant.
Moderate Cyp2d6 Inhibitors/Oliceridine
SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.
MECHANISM OF ACTION: Oliceridine is metabolized equally by CYP2D6 and CYP3A4. Oliceridine metabolism may be inhibited by inhibitors of CYP2D6 or CYP3A4.(1)
CLINICAL EFFECTS: The concurrent administration of a strong or moderate CYP2D6 or strong or moderate CYP3A4 inhibitor may result in elevated levels of and toxicity from oliceridine including profound sedation, respiratory depression, coma, and/or death.(1)
PREDISPOSING FACTORS: Inhibition of both CYP2D6 and CYP3A4 pathways may result in a greater increase in the levels of and toxcity of oliceridine.(1)
PATIENT MANAGEMENT: Caution should be used when administering oliceridine to patients taking strong or moderate inhibitors of CYP2D6 or CYP3A4. Dosage adjustments should be made if warranted. Closely monitor these patients for respiratory depression and sedation at frequent intervals and evaluate subsequent doses based on response. If concomitant use of a strong or moderate CYP2D6 or CYP3A4 inhibitor is necessary, less frequent dosing of oliceridine may be required. If a strong or moderate CYP2D6 or CYP3A4 inhibitor is discontinued, increase of the oliceridine dosage may be necessary. Monitor for signs of opioid withdrawal. Patients receiving concurrent therapy with both a strong or moderate CYP3A4 inhibitor and CYP2D6 inhibitors may be at greater risk of adverse effects. Patient who are CYP2D6 normal metabolizers taking a CYP2D6 inhibitor and a strong CYP3A4 inhibitor may require less frequent dosing of oliceridine.(1) Respiratory depression can occur at any time during opioid therapy, especially during therapy initiation and following dosage increases. The risk of opioid-related overdose or overdose-related death is increased with higher opioid doses, and this risk persists over the course of therapy. Consider these risks when using concurrently with other agents that may cause CNS depression.(2) Discuss opioid reversal agents (e.g., naloxone, nalmefene) with all patients when prescribing or renewing an opioid analgesic or medicine to treat opioid use disorder (OUD). Consider prescribing an opioid reversal agent (e.g., naloxone, nalmefene) to patients prescribed medicines to treat OUD or opioid analgesics who are at increased risk of opioid overdose (such as those taking CNS depressants) and when a patient has household members/close contacts at risk for accidental overdose. Discuss the options for obtaining an opioid reversal agent (e.g., prescription, over-the-counter, or as part of a community-based program).(3)
DISCUSSION: In a study of four healthy subjects who are CYP2D6 poor metabolizers, itraconazole (200 mg daily for 5 days) increased the area-under-curve (AUC) of single-dose oliceridine (0.25 mg) by 80%.(1) In a study of subjects who were not CYP2D6 poor metabolizers, ketoconazole (200 mg for 2 doses 10 hours apart) did not affect the pharmacokinetics of oliceridine.(1) Moderate CYP2D6 inhibitors include: abiraterone, asunaprevir, capivasertib, cinacalcet, duloxetine, eliglustat, escitalopram, lorcaserin, levomepromazine, mirabegron, moclobemide, and rolapitant.(4)
Selected Cyp2d6 Inhibitors/Metoprolol
SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.
MECHANISM OF ACTION: CYP2D6 inhibitors may inhibit the metabolism of metoprolol.(1,2)
CLINICAL EFFECTS: Concurrent use of CYP2D6 inhibitors may result in elevated levels of and toxicity from metoprolol.(1,2)
PREDISPOSING FACTORS: The interaction may be more severe in patients who are ultrarapid metabolizers of CYP2D6,(1,2) elderly,(3) and on higher doses of beta-blockers.(3)
PATIENT MANAGEMENT: Monitor patients receiving concurrent therapy with metoprolol and inhibitors of CYP2D6. The dosage of metoprolol may need to be adjusted.(1,2) The effects of rolapitant, a moderate CYP2D6 inhibitor, on CYP2D6 are expected to last at least 28 days after administration.(4)
DISCUSSION: In a case report, a patient maintained on metoprolol developed bradycardia following the addition of bupropion.(5) In a study in 20 healthy females, diphenhydramine increased the AUC of metoprolol by 21%. Heart rate reduction increased 29%.(6) In a randomized study in 16 healthy subjects, diphenhydramine decreased metoprolol oral and nonrenal clearance by 2-fold in extensive 2D6 metabolizers. In extensive 2D6 metabolizers, metoprolol-induced effects on heart rate, systolic blood pressure, and aortic blood flow peak velocity were all increased. There were no effects of diphenhydramine in poor metabolizers.(7) Fluoxetine has been shown to inhibit metoprolol metabolism in vitro.(8) There is a case report of severe bradycardia following the addition of fluoxetine to metoprolol.(9) In a 3-way, randomized, cross-over study in healthy subjects, paroxetine (20 mg daily) increased the area-under-curve (AUC) of both S- and R-metoprolol by 3-fold, and 4-fold, respectively, regardless of whether the formulation of metoprolol was immediate release or extended release. Concurrent paroxetine also significantly decreased heart rate and blood pressure when compared to metoprolol alone.(10) In an open-label, randomized, cross-over study in 10 healthy subjects, paroxetine increased the AUC of S-metoprolol and R-metoprolol from an immediate release formulation (50 mg)by 4-fold and 5-fold, respectively. Paroxetine increased the AUC of S-metoprolol and R-metoprolol from an extended release formulation (100 mg) by 3-fold and 4-fold, respectively.(11) In a study in patients with acute myocardial infarction and depression, paroxetine (20 mg daily) increased the AUC of metoprolol 3-fold. Mean heart rate was significantly lower following the addition of paroxetine to metoprolol. Two patients experienced bradycardia and severe orthostatic hypotension.(12) In an open trial in 8 healthy males, paroxetine (20 mg daily) increased the AUC of S-metoprolol and R-metoprolol by 4-fold and 7-fold, respectively.(13) There are case reports of complete atrioventricular block(14) and bradycardia(15) with concurrent metoprolol and paroxetine. A systematic review and meta-analysis of CYP2D6 interactions between metoprolol and either paroxetine or fluoxetine reviewed 9 articles including 4 primary and 2 observational studies as well as 3 case reports. Experimental studies noted paroxetine increased the AUC of metoprolol 3-fold to 5-fold and significantly decreased blood pressure and heart rate. Paroxetine and fluoxetine have shown equipotent inhibitor capacity on CYP2D6. The metabolite, norfluoxetine, is also an inhibitor of CYP2D6.(16) A retrospective cohort study evaluated morbidity in patients on a beta-blocker primarily metabolized by CYP2D6 (e.g., nebivolol, metoprolol, carvedilol, propranolol, labetalol) and started on a strong or moderate CYP2D6-inhibiting antidepressant (e.g., fluoxetine, paroxetine, bupropion, duloxetine). Use of such an antidepressant with a beta-blocker was associated with an increased risk of hospitalization or ED visit due to an adverse hemodynamic event (HR 1.53, 95% CI 1.03-2.81, p=0.04).(3) CYP2D6 inhibitors include: abiraterone, bupropion, celecoxib, cinacalcet, citalopram, dacomitinib, dimenhydrinate, diphenhydramine, duloxetine, escitalopram, fedratinib, fluoxetine, hydroxychloroquine, imatinib, lorcaserin, osilodrostat, paroxetine, ranitidine, ranolazine, rolapitant, and sertraline. One or more of the drug pairs linked to this monograph have been included in a list of interactions that could be considered for classification as "non-interruptive" in EHR systems. This DDI subset was vetted by an expert panel commissioned by the U.S. Office of the National Coordinator (ONC) for Health Information Technology.
Selected Cyp2d6 Inhibitors/Propranolol
SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.
MECHANISM OF ACTION: CYP2D6 inhibitors may inhibit the metabolism of propranolol.(1)
CLINICAL EFFECTS: Concurrent use of CYP2D6 inhibitors may result in elevated levels of and toxicity from propranolol, including hypotension and bradycardia.(1)
PREDISPOSING FACTORS: None determined.
PATIENT MANAGEMENT: Monitor patients receiving concurrent therapy with propranolol and CYP2D6 inhibitors. The dosage of propranolol may need to be adjusted.(1)
DISCUSSION: In a pharmacokinetic study in 16 healthy volunteers, concurrent use of quinidine 200 mg (a CYP2D6 inhibitor) increased the area-under-curve (AUC) of propranolol by 2.29-fold.(2) In a pharmacokinetic study in 6 healthy subjects, concurrent use of quinidine increased propranolol AUC 2-fold.(3) A retrospective review of concurrent use of propranolol and antidepressants evaluated the risk of hospitalization or emergency room visit within 30 days of concurrent prescription. In patients receiving antidepressants with moderate to strong CYP2D6 inhibitory effects, patient were an increased risk compared to patients receiving no antidepressants (Hazard Ratio (HR) = 1.53; 95% CI 1.03-2.81 vs. HR = 1.24; 95% CI 0.82-1.88).(4) Case reports of bradycardia and cardiac adverse effects have been reported with concurrent use of propranolol and the antidepressants fluoxetine and paroxetine (strong CYP2D6 inhibitors).(5) Strong CYP2D6 inhibitors include: bupropion, dacomitinib, fluoxetine, mavorixafor, and paroxetine. Moderate CYP2D6 inhibitors include: abiraterone, asunaprevir, berotralstat, capivasertib, cinacalcet, duloxetine, eliglustat, escitalopram, levomepromazine, lorcaserin, mirabegron, moclobemide, quinine, ranolazine, and rolapitant. Weak CYP2D6 inhibitors include: desvenlafaxine, diphenhydramine, dimenhydrinate, dronabinol, fedratinib, hydroxychloroquine, imatinib, osilodrostat, ranitidine, and sertraline.(6)
Selected Moderate To Strong Cyp2d6 Inhibitors/Tramadol
SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.
MECHANISM OF ACTION: Abiraterone, asunaprevir, berotralstat, bupropion, cinacalcet, dacomitinib, dronedarone, duloxetine, eliglustat, fluoxetine, hydroquinidine, levomepromazine, levomethadone, lorcaserin, mirabegron, paroxetine, quinidine, rolapitant, oral terbinafine, and tipranavir are moderate or strong inhibitors of CYP2D6 and may decrease conversion of tramadol to its more active O-demethylated metabolite (M1).(1-6) M1 is up to 6 times more potent than tramadol in producing analgesia.(1)
CLINICAL EFFECTS: Tramadol analgesic efficacy may be decreased due to lower mu-opioid receptor mediated analgesia.(1,9,10) Higher concentrations of tramadol may be associated with increased inhibition of norepinephrine and serotonin reuptake, increasing risk for seizures and serotonin syndrome.(1) Symptoms of serotonin syndrome may include tremor, agitation, diaphoresis, hyperreflexia, clonus, tachycardia, hyperthermia, and muscle rigidity.(7)
PREDISPOSING FACTORS: Risk for seizure may be increased with tramadol doses above the recommended range, in patients with metabolic disorders, alcohol or drug withdrawal, infection of the central nervous system, or with a history of seizures or head trauma.(1) Treatment with multiple medications which increase serotonin levels, or with medications which inhibit the metabolism of serotonin increasing drugs are risk factors for serotonin syndrome.(1,7) Patients with CYP2D6 ultrarapid, normal, and intermediate metabolizer phenotypes may be affected to a greater extent by CYP2D6 inhibitors. For patients on strong CYP2D6 inhibitors, the predicted phenotype is a CYP2D6 poor metabolizer.(14) Patients who are CYP2D6 poor metabolizers lack CYP2D6 function and are not affected by CYP2D6 inhibition.(14)
PATIENT MANAGEMENT: If a CYP2D6 inhibitor is started in a patient stabilized on long term tramadol therapy, monitor for loss of analgesic efficacy. When initiating tramadol in a patient stabilized on a moderate or strong CYP2D6 inhibitor, anticipate lower analgesic efficacy. Hospitalized patients may need added doses of rescue analgesics to achieve adequate pain control.(9,10) To decrease risk for serotonin syndrome, consider change to an alternative analgesic for patients taking other serotonin increasing drugs in addition to concomitant tramadol and a CYP2D6 inhibitor. If a CYP2D6 inhibitor is discontinued, consider lowering the dose of tramadol until patient achieves stable drug effects. The effects of rolapitant, a moderate CYP2D6 inhibitor, on CYP2D6 are expected to last at least 28 days after administration.(12)
DISCUSSION: Tramadol and its M1 metabolite both contribute to analgesic efficacy. Tramadol inhibits the reuptake of norepinephrine and serotonin with minimal opioid receptor binding. The M1 metabolite has 200 times greater binding affinity for the mu-opioid receptor than tramadol and is 6 times more potent in producing analgesia.(1) CYP2D6 converts tramadol to M1.(1,8) A prospective study evaluated the impact of 2D6 genotype on tramadol analgesia after abdominal surgery. Rescue doses of opioids were required in 47% of poor metabolizers (PM) versus 22% of extensive metabolizers (EM) of 2D6.(9) A follow-up study included 2D6 EM patients who received concomitant treatment with 2D6 inhibitors. Levels of the M1 metabolite were decreased by 80-90% compared with EM patients not taking 2D6 inhibitors. The authors noted some EM patients were converted to the PM phenotype.(10) In both studies, higher M1 levels were associated with greater analgesic efficacy and decreased need for rescue opioid treatment.(9,10) A study in 12 healthy volunteers found that a single dose of tramadol (50 mg) given to patients on terbinafine (a strong CYP2D6 inhibitor) resulted in tramadol AUC and Cmax that were 2.1-fold and 1.5-fold higher, respectively, than tramadol given alone. The AUC and Cmax of M1 were decreased by 64 % and 78 %, respectively.(13) A single dose of rolapitant increased dextromethorphan, a CYP2D6 substrate, about 3-fold on days 8 and day 22 following administration. Dextromethorphan levels remained elevated by 2.3-fold on day 28 after single dose rolapitant. The inhibitory effects of rolapitant on CYP2D6 are expected to persist beyond 28 days.(12)
Contraindications
*None.
- Child-pugh class B hepatic impairment
- Child-pugh class C hepatic impairment
- Anemia
- Disease of liver
- Hypokalemia
- Neutropenic disorder
- Pregnancy
- Thrombocytopenic disorder
- Acute myocardial infarction
- Cardiac arrhythmia
- Chronic heart failure
- Hypertension
Adverse reactions
The most common adverse reactions of niraparib/abiraterone (>=10% of patients) reported in clinical studies, including laboratory abnormalities, are decreased hemoglobin, decreased lymphocytes, decreased white blood cells, musculoskeletal pain, fatigue, decreased platelets, increased alkaline phosphatase, constipation, hypertension, nausea, decreased neutrophils, increased creatinine, increased potassium, decreased potassium, increased AST, increased ALT, edema, dyspnea, decreased appetite, vomiting, dizziness, COVID-19, headache, abdominal pain, hemorrhage, urinary tract infection, cough, insomnia, increased bilirubin, weight decreased, arrhythmia, fall, and pyrexia.
More Frequent
- Abnormal hepatic function tests
- Abnormal hepatic function tests
- Accidental fall
- Anemia
- Anemia
- Cardiac arrhythmia
- Fracture
- Hypertension
- Hypertension
- Hypokalemia
- Hypomagnesemia
- Increased alanine transaminase
- Increased aspartate transaminase
- Leukopenia
- Lymphopenia
- Neutropenic disorder
- Thrombocytopenic disorder
Less Frequent
- Atrial fibrillation
- Hyperbilirubinemia
- Hypokalemia
- Increased alanine transaminase
- Increased aspartate transaminase
- Kidney disease with reduction in glomerular filtration rate (GFr)
Rare or Very Rare
- Acute hepatic failure
- Acute myeloid leukemia
- Acute myocardial infarction
- Adrenocortical insufficiency
- Anaphylaxis
- Anaphylaxis
- Cardiomegaly
- Cardiomyopathy
- Heart failure
- Hepatitis
- Hypersensitivity drug reaction
- Hypertensive crisis
- Hypoglycemic disorder
- Interstitial pneumonitis
- Interstitial pneumonitis
- Myelodysplastic syndrome
- Myocardial ischemia
- Pancytopenia
- Posterior reversible encephalopathy syndrome
- Renal failure
- Rhabdomyolysis
More Frequent
- Abdominal distension
- Acute abdominal pain
- Anorexia
- Arthralgia
- Arthralgia
- Back pain
- Body fluid retention
- Bruising
- Constipation
- Cough
- Cough
- Diarrhea
- Diarrhea
- Dizziness
- Dysgeusia
- Dyspepsia
- Dyspepsia
- Dyspnea
- Dyspnea
- Edema
- Fatigue
- Fatigue
- Fever
- Flushing
- General weakness
- Headache disorder
- Headache disorder
- Hematuria
- Hypercholesterolemia
- Hyperglycemia
- Hyperglycemia
- Hypertriglyceridemia
- Increased urinary frequency
- Insomnia
- Insomnia
- Lymphopenia
- Musculoskeletal pain
- Myalgia
- Nausea
- Nausea
- Nocturia
- Palpitations
- Pharyngitis
- Pharyngitis
- Skin rash
- Skin rash
- Stomatitis
- Symptoms of anxiety
- Upper respiratory infection
- Urinary tract infection
- Urinary tract infection
- Vomiting
- Vomiting
- Xerostomia
Less Frequent
- Bronchitis
- Chest pain
- Conjunctivitis
- Depression
- Epistaxis
- Increased pulse rate
- Peripheral edema
- Tachycardia
- Weight loss
Rare or Very Rare
- Acute cognitive impairment
- Hallucinations
- Memory impairment
- Myopathy
- Skin photosensitivity
Precautions
No enhanced messaging available.
Safety and effectiveness of niraparib/abiraterone in pediatric patients have not been established.
The safety and efficacy of niraparib/abiraterone have not been established in females. There are no human data on the use of niraparib/abiraterone in pregnant women. Based on findings from animal studies and the mechanism of action, niraparib/abiraterone can cause fetal harm and potential loss of pregnancy. Niraparib has the potential to cause teratogenicity and/or embryo-fetal death since niraparib is genotoxic and targets actively dividing cells in animals and patients (e.g., bone marrow). In animal reproduction studies, oral administration of abiraterone acetate to pregnant rats during organogenesis (gestational days 6-17) caused adverse developmental effects at maternal exposures approximately >=0.03 times the human exposure (AUC) at the recommended dose. Findings included embryo-fetal lethality (increased postimplantation loss and resorptions and decreased number of live fetuses), fetal developmental delay, and urogenital effects (bilateral ureter dilation) at dosages >=10 mg/kg/day, decreased fetal anogenital distance at >=30 mg/kg/day, and decreased fetal body weight at 100 mg/kg/day, which represents approximately 0.03, 0.1, and 0.3 times the AUC of patients receiving 1,000 mg of abiraterone acetate, respectively.
The safety and efficacy of niraparib/abiraterone have not been established in females. There is no information available on the presence of niraparib or abiraterone in human milk, or on the effects of these drugson the breast-fed child or milk production.
The manufacturer makes no specific dosage recommendations for geriatric patients.
Of the 113 patients with BRCAgene alteration(s) who received niraparib/abiraterone in the MAGNITUDE trial, 34.5% of patients were less than 65 years of age, 38.9% of patients were 65 to 74 years, and 26.5% were 75 years and older. There was an insufficient number of patients withBRCA gene alteration(s) treated with niraparib/abiraterone in the MAGNITUDE trial to accurately characterize efficacy or safety by age.
ICD codes
| Code | Type | Description |
|---|---|---|
| Metastatic castration-resistant prostate cancer with BRCA mutation | ||
| C61 | ICD10CM | Malignant neoplasm of prostate |
| Z19.2 | ICD10CM | Hormone resistant malignancy status |
| Metastatic castration-sensitive prostate cancer with BRCa2 mutation | ||
| C61 | ICD10CM | Malignant neoplasm of prostate |
| Z19.1 | ICD10CM | Hormone sensitive malignancy status |
ICD code information from First Databank (FDB).
Formulary status
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Last reviewed · Source: First Databank (FDB) drug data
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