Ethambutol Hcl (ethambutol HCl)

In patients with impaired renal function, doses and/or frequency of administration of ethambutol hydrochloride should be modified in response to the degree of renal impairment. Some clinicians suggest that if the creatinine clearance is 70-100 mL/minute, dosage of ethambutol hydrochloride should not exceed 15 mg/kg daily, and if the creatinine clearance is less than 70 mL/minute, dosage should be further reduced. Other clinicians have suggested that the usual dose be administered every 24-36 hours in patients with creatinine clearances of 10-50 mL/minute and every 48 hours in patients with creatinine clearances less than 10 mL/minute.

Ethambutol hydrochloride is administered orally.

There is no enhanced messaging for this drug.

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

Antibiotics/Fecal Microbiota

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: Fecal microbiota is a suspension of live bacteria, which may be compromised by concurrent use of antibiotics.(1)

CLINICAL EFFECTS: Antibiotics may decrease the effectiveness of fecal microbiota.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Antibiotics should not be used concurrently with fecal microbiota. Antibacterial treatment should be completed for 24 to 72 hours before initiating treatment with fecal microbiota. Do not use antibiotics for up to 8 weeks after fecal microbiota.(1)

DISCUSSION: Antibiotics may compromise the effectiveness of fecal microbiota.

Antibiotics/Fecal Microbiota Spores

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: Fecal microbiota spores is a suspension of live bacterial spores, which may be compromised by concurrent use of antibiotics.(1)

CLINICAL EFFECTS: Antibiotics may decrease the effectiveness of fecal microbiota spores.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Antibiotics should not be used concurrently with fecal microbiota spores. Antibacterial treatment should be completed for 2 to 4 days before initiating treatment with fecal microbiota spores.(1)

DISCUSSION: Antibiotics may compromise the effectiveness of fecal microbiota spores.

Antimicrobials/Live Typhoid Vaccine

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 antimicrobial may be active against the organism in the live-vaccine. Antimicrobial therapy may prevent the vaccine organism from replicating enough to trigger an immune response.(1)

CLINICAL EFFECTS: Vaccination may be ineffective.

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Do not give oral typhoid vaccine until 72 hours after the last dose of antimicrobial. If possible, to optimize vaccine effectiveness, do not start antibacterial drugs for 72 hours after the last dose of oral typhoid vaccine. A longer interval should be considered for long-acting antimicrobials, such as azithromycin.(3)

DISCUSSION: Because antimicrobial therapy may prevent sufficient vaccine-organism replication to generate an immune response, the manufacturer of live-attenuated typhoid vaccine and the Centers for Disease Control (CDC) state that the vaccine should not be administered to patients receiving antimicrobial therapy.(1-3)

Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

Selected Antimycobacterials/Live Bcg

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: Bacillus Calmette-Guerin (BCG) is a live, attenuated strain of Mycobacterium bovis (M.bovis) used to induce a granulomatous response in the treatment of localized bladder cancer and as a vaccine to prevent tuberculosis.(1-2) Co-treatment with antibacterial agents active against M.bovis may lead to an attenuation of the immune response associated with BCG administration.(1-2)

CLINICAL EFFECTS: The effectiveness of chemotherapy may be impaired, or the vaccine may be ineffective. Agents linked to this monograph may have activity against M.bovis: amikacin, capreomycin, ciprofloxacin, clofazimine, cycloserine, ethambutol, ethionamide, gatifloxacin, isoniazid, kanamycin, levofloxacin, moxifloxacin, ofloxacin, rifabutin, rifampin, rifapentine, and streptomycin.

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Intravesical instillation of BCG should be postponed during treatment with antibacterials which may decrease effectiveness.(2) Administration of BCG vaccine to patients receiving antibiotic therapy should only be done under close medical supervision.(1) If a patient develops a systemic BCG infection due to intravesicular or vaccine administration, treatment with multiple antimycobacterial agents may be required.

DISCUSSION: Because antibiotic therapy may prevent sufficient vaccine-organism replication to generate an immune response, the manufacturer of BCG vaccine states that administration of BCG vaccine to patients receiving antibiotic therapy should only be done under close medical supervision.(1) Pyrazinamide is not included in this interaction as BCG is not sensitive to pyrazinamide.(2)

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

Ethambutol/Aluminum Hydroxide

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

MECHANISM OF ACTION: Aluminum hydroxide may bind to ethambutol in the gastrointestinal tract, preventing its absorption.

CLINICAL EFFECTS: Simultaneous administration of an aluminum hydroxide-containing antacid may decrease levels and effectiveness of ethambutol.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: The US manufacturer of ethambutol recommends that the administration times of ethambutol and aluminum hydroxide-containing antacids be separated by 4 hours.(1)

DISCUSSION: In a study in 13 tuberculosis patients, simultaneous administration of ethambutol with aluminum hydroxide decreased the area-under-curve (AUC) and urinary excretion of ethambutol by 20% and 13%, respectively.(1,2) In a study in 14 healthy subjects, simultaneous administration of ethambutol with an aluminum-magnesium antacid, ethambutol AUC and maximum concentration (Cmax) decreased by 10% and 29%, respectively.(3)

There is no enhanced messaging for this drug.

There are no contraindication contraindications for this drug.

• Kidney disease with reduction in glomerular filtration rate (GFr)
• Optic neuritis

• Cataracts
• Diabetic retinopathy
• Gout

There is no enhanced messaging for this drug.

Less Frequent

• Acute gouty arthritis
• Hyperuricemia

Rare or Very Rare

• Allergic dermatitis
• Anaphylaxis
• Drug fever
• Drug-induced hepatitis
• Erythema multiforme
• Hypersensitivity drug reaction
• Leukopenia
• Neutropenic disorder
• Optic neuritis
• Peripheral neuropathy
• Pruritus of skin
• Pulmonary infiltrates
• Reduced visual acuity
• Skin rash
• Thrombocytopenic disorder

Less Frequent

• Abdominal pain with cramps
• Acute cognitive impairment
• Anorexia
• Headache disorder
• Nausea
• Vomiting

Rare or Very Rare

• Dizziness

No enhanced messaging available.

No enhanced messaging available.

Ethambutol has caused teratogenic effects in animals when used in high doses. Although safe use of the drugs during pregnancy has not been definitely established, ethambutol (combined with isoniazid or with isoniazid and rifampin) has been used to treat clinical tuberculosis in pregnant women and has not been reported to date to cause adverse effects on the fetus The manufacturer states that ethambutol should be used during pregnancy only when the potential benefits justify the possible risks to the fetus. The ATS, CDC, and IDSA state that ethambutol is considered safe for use in pregnant women.

No enhanced messaging available.

No enhanced messaging available.