Xofluza (baloxavir marboxil)

No dosing information is available for this tab.

Baloxavir marboxil is administered orally without regard to meals. However, concomitant administration with dairy products; calcium-fortified beverages; or antacids, laxatives, or oral supplements containing polyvalent cations (aluminum, calcium, iron, magnesium, selenium, or zinc) should be avoided. (See Antacids and Other Preparations Containing Polyvalent Cations under Drug Interactions.)

Baloxavir marboxil is commercially available as tablets or as granules for oral suspension that must be suspended in water prior to administration.

No dosing information is available for this tab.

After baloxavir marboxil is converted in vivo to baloxavir, the active metabolite, baloxavir is metabolized principally by uridine diphosphate-glucuronosyltransferase (UGT) 1A3 and, to a minor extent, by cytochrome P-450 (CYP) isoenzyme 3A4.

In vitro studies indicate that baloxavir marboxil and baloxavir do not inhibit CYP isoenzymes 1A2, 2B6, 2C8, 2C9, 2C19, or 2D6 and do not induce CYP isoenzymes 1A2, 2B6, or 3A4.

Baloxavir marboxil and baloxavir are both substrates of P-glycoprotein (P-gp).

In vitro studies indicate that baloxavir marboxil and baloxavir do not inhibit UGT1A1, 1A3, 1A4, 1A6, 1A9, 2B7, or 2B15. In addition, baloxavir does not inhibit organic anion transport polypeptide (OATP) 1B1, OATP1B3, organic cation transporter (OCT) 1, OCT2, organic anion transporter (OAT) 1, OAT3, multidrug and toxin extrusion (MATE) 1, or MATE2K.

Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

Selected Antiviral Agents/Influenza Virus Vaccine Live

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: Amantadine,(1) oseltamivir,(2) rimantadine,(3) zanamivir,(4) and baloxavir,(5) may inactivate the intranasal live influenza virus vaccine, preventing the body from developing an immune response.

CLINICAL EFFECTS: Administration of amantadine,(1) oseltamivir,(2) rimantadine,(3) zanamivir,(4) and baloxavir,(5) may render the intranasal live influenza virus vaccine ineffective.

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: The US manufacturers of amantadine,(1) oseltamivir,(2) rimantadine,(3) zanamivir(4), baloxavir(5), and the intranasal live influenza virus vaccine(6) state that these agents should not be initiated within 2 weeks of the administration of the intranasal live influenza virus vaccine and that the vaccine should not be administered within 48 hours of the discontinuation of these agents. Inactivated influenza vaccine may be used at any time.(1)

DISCUSSION: Because antiviral drugs such as amantadine,(1) oseltamivir,(2) rimantadine,(3) zanamivir,(4) and baloxavir (5) inhibit the replication of live viruses, these agents may interfere with the efficacy of the intranasal live influenza virus vaccine.

There are no severe interactions for this drug.

Moderate Interaction: Assess the risk to the patient and take action as needed.

Baloxavir/Polyvalent Cations

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Aluminum, calcium, iron, magnesium, selenium, and zinc may form chelation compounds with baloxavir.(1)

CLINICAL EFFECTS: Simultaneous administration of products containing aluminum, calcium, iron, magnesium, selenium, and zinc may result in decreased levels of and clinical effects from baloxavir.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Avoid concurrent administration of baloxavir with cation-containing products.(1)

DISCUSSION: A significant decrease in baloxavir exposure was observed when baloxavir was coadministered with calcium, aluminum, magnesium, or iron in monkeys. No studies have been conducted in humans.(1)

*History of hypersensitivity to baloxavir marboxil or any ingredient in the formulation.

There are no contraindication contraindications for this drug.

There are no severe contraindications for this drug.

• No disease contraindications

Adverse effects reported in 1% or more of patients receiving baloxavir marboxil in clinical studies include GI effects (nausea, diarrhea), bronchitis, sinusitis, and headache.

Rare or Very Rare

• Anaphylaxis
• Angioedema
• Bloody diarrhea
• Colitis
• Erythema multiforme
• Facial edema
• Hypersensitivity drug reaction
• Tongue swelling
• Urticaria

More Frequent

• Bronchitis
• Diarrhea
• Headache disorder
• Nausea
• Pharyngitis
• Sinusitis

Rare or Very Rare

• Behavioral disorders
• Black tarry stools
• Delirium
• Hallucinations
• Skin rash
• Voice change
• Vomiting

No enhanced messaging available.

Safety and efficacy of baloxavir marboxil have not been established in pediatric patients younger than 12 years of age.

Safety and efficacy of baloxavir marboxil for the treatment of influenza in adolescents 12 years of age or older weighing 40 kg or more were established in a phase 3, randomized, double-blind, placebo-controlled study. Data from this study indicated that the safety profile of the drug in adolescent patients 12 years of age or older is similar to that reported in adults.

Safety and efficacy of baloxavir marboxil for postexposure prophylaxis of influenza in adolescents 12 years of age or older weighing 40 kg or more is supported by a randomized, double-blind, placebo-controlled trial conducted in Japan that included 12 individuals 12-17 years of age who received the drug for postexposure prophylaxis. Adverse effects reported in these adolescents were similar to those reported in adults in the trial who received the drug.

There are no adequate and well-controlled studies using baloxavir marboxil in pregnant women to inform a drug-associated risk of adverse developmental outcomes.

In animal reproduction studies, no adverse embryofetal effects were observed in rats or rabbits receiving oral baloxavir marboxil in dosages resulting in baloxavir exposures approximately 5 or 7 times, respectively, the systemic baloxavir exposures achieved in humans with the maximum recommended human dosage.

Pregnant women are at increased risk for severe complications from influenza, which may lead to adverse pregnancy and/or fetal outcomes including maternal death, stillbirths, birth defects, preterm delivery, low birthweight, and small size for gestational age.

CDC states that baloxavir marboxil is not recommended for the treatment of influenza in pregnant women because of the lack of safety and efficacy data in such patients. Oseltamivir is the preferred antiviral for the treatment of suspected or confirmed influenza and prevention of influenza in women who are pregnant or up to 2 weeks postpartum.

It is not known whether baloxavir marboxil is distributed into human milk, affects milk production, or has any effects on breast-fed infants. Baloxavir and its metabolites are distributed into milk in rats.

The manufacturer states that the benefits of breast-feeding and the importance of baloxavir marboxil to the woman should be considered along with the potential adverse effects on the breast-fed child from the drug or from the underlying maternal condition.

CDC states that baloxavir marboxil is not recommended for the treatment of influenza in nursing women because of the lack of safety data in such patients.

Safety and efficacy of baloxavir marboxil for the treatment of acute, uncomplicated influenza in adults 65 years of age or older have been established and are supported by a randomized, double-blind, controlled trial that included 209 adults in this age group at high risk of influenza-related complications who were treated with the drug. The median time to improvement of influenza symptoms in patients 65 years of age or older was 70 hours in those treated with baloxavir marboxil compared with 88 hours in those who received placebo. The safety profile of the drug in patients 65 years of age or older was similar to that reported in the overall trial population, with the exception of nausea (reported in 6% of adults 65 years of age or older compared with 1% of those 18-64 years of age).