Rifabutin

Generic Name: rifabutin

Rifamycin Antimycobacterial [EPC]Over-the-Counter (OTC)

Brand Names:

Rifabutin

DESCRIPTION Rifabutin Capsules for oral administration contain 150 mg of the rifamycin antimycobacterial agent rifabutin, USP, per capsule along with the inactive ingredients, microcrystalline cellulose, sodium lauryl sulfate, colloidal silicon dioxide, magnesium stearate. The hard gelatin capsule contains titanium dioxide, red iron oxide, gelatin, sodium lauryl sulfate and purified water.

Overview

DESCRIPTION Rifabutin Capsules for oral administration contain 150 mg of the rifamycin antimycobacterial agent rifabutin, USP, per capsule along with the inactive ingredients, microcrystalline cellulose, sodium lauryl sulfate, colloidal silicon dioxide, magnesium stearate. The hard gelatin capsule contains titanium dioxide, red iron oxide, gelatin, sodium lauryl sulfate and purified water.

Uses

INDICATIONS & USAGE Rifabutin Capsules are indicated for the prevention of disseminated Mycobacterium avium complex (MAC) disease in patients with advanced HIV infection.

Dosage

DOSAGE & ADMINISTRATION It is recommended that Rifabutin Capsules be administered at a dose of 300 mg once daily. For those patients with propensity to nausea, vomiting, or other gastrointestinal upset, administration of Rifabutin at doses of 150 mg twice daily taken with food may be useful. For patients with severe renal impairment (creatinine clearance less than 30 mL/min), consider reducing the dose of Rifabutin by 50%, if toxicity is suspected. No dosage adjustment is required for patients with mild to moderate renal impairment. Reduction of the dose of Rifabutin may also be needed for patients receiving concomitant treatment with certain other drugs (see PRECAUTIONS- Drug Interactions) . Mild hepatic impairment does not require a dose modification.

Side Effects

ADVERSE REACTIONS Adverse Reactions from Clinical Trials Rifabutin Capsules were generally well tolerated in the controlled clinical trials. Discontinuation of therapy due to an adverse event was required in 16% of patients receiving Rifabutin, compared to 8% of patients receiving placebo in these trials. Primary reasons for discontinuation of Rifabutin were rash (4% of treated patients), gastrointestinal intolerance (3%), and neutropenia (2%). The following table enumerates adverse experiences that occurred at a frequency of 1% or greater, among the patients treated with Rifabutin in studies 023 and 027.

Interactions

DRUG INTERACTIONS Effect of Rifabutin on the Pharmacokinetics of Other Drugs Rifabutin induces CYP3A enzymes and therefore may reduce the plasma concentrations of drugs metabolized by those enzymes. This effect may reduce the efficacy of standard doses of such drugs, which include itraconazole, clarithromycin, and saquinavir. Effect of Other Drugs on Rifabutin Pharmacokinetics Some drugs that inhibit CYP3A may significantly increase the plasma concentration of rifabutin. Therefore, carefully monitor for rifabutin associated adverse events in those patients also receiving CYP3A inhibitors, which include fluconazole and clarithromycin. In some cases, the dosage of Rifabutin may need to be reduced when it is coadministered with CYP3A inhibitors.

Warnings

WARNINGS Tuberculosis Rifabutin Capsules must not be administered for MAC prophylaxis to patients with active tuberculosis. Patients who develop complaints consistent with active tuberculosis while on prophylaxis with Rifabutin should be evaluated immediately, so that those with active disease may be given an effective combination regimen of anti-tuberculosis medications. Administration of Rifabutin as a single agent to patients with active tuberculosis is likely to lead to the development of tuberculosis that is resistant both to Rifabutin and to rifampin. There is no evidence that Rifabutin is an effective prophylaxis against M. tuberculosis . Patients requiring prophylaxis against both M. tuberculosis and Mycobacterium avium complex may be given isoniazid and Rifabutin concurrently. CONTRAINDICATIONS Rifabutin Capsules are contraindicated in patients who have had clinically significant hypersensitivity to rifabutin or to any other rifamycins.

Pregnancy

PREGNANCY Rifabutin should be used in pregnant women only if the potential benefit justifies the potential risk to the fetus. There are no adequate and well-controlled studies in pregnant or breastfeeding women. Reproduction studies have been carried out in rats and rabbits given rifabutin using dose levels up to 200 mg/kg (about 6 to 13 times the recommended human daily dose based on body surface area comparisons). No teratogenicity was observed in either species.

Storage

HOW SUPPLIED Rifabutin Capsules, USP are supplied as hard gelatin capsule shell with maroon colored cap and body, imprinted with black ink as 041 on cap and Novitium 150 mg (150 mg under Novitium) on body, filled with red-violet powder, each containing 150 mg of Rifabutin, USP.

Frequently Asked Questions

What is Rifabutin used for?

INDICATIONS & USAGE Rifabutin Capsules are indicated for the prevention of disseminated Mycobacterium avium complex (MAC) disease in patients with advanced HIV infection.

What are the side effects of Rifabutin?

ADVERSE REACTIONS Adverse Reactions from Clinical Trials Rifabutin Capsules were generally well tolerated in the controlled clinical trials. Discontinuation of therapy due to an adverse event was required in 16% of patients receiving Rifabutin, compared to 8% of patients receiving placebo in these trials. Primary reasons for discontinuation of Rifabutin were rash (4% of treated patients), gastrointestinal intolerance (3%), and neutropenia (2%). The following table enumerates adverse experiences that occurred at a frequency of 1% or greater, among the patients treated with Rifabutin in studies 023 and 027.

Can I take Rifabutin during pregnancy?

PREGNANCY Rifabutin should be used in pregnant women only if the potential benefit justifies the potential risk to the fetus. There are no adequate and well-controlled studies in pregnant or breastfeeding women. Reproduction studies have been carried out in rats and rabbits given rifabutin using dose levels up to 200 mg/kg (about 6 to 13 times the recommended human daily dose based on body surface area comparisons). No teratogenicity was observed in either species.

What are the important warnings for Rifabutin?

WARNINGS Tuberculosis Rifabutin Capsules must not be administered for MAC prophylaxis to patients with active tuberculosis. Patients who develop complaints consistent with active tuberculosis while on prophylaxis with Rifabutin should be evaluated immediately, so that those with active disease may be given an effective combination regimen of anti-tuberculosis medications. Administration of Rifabutin as a single agent to patients with active tuberculosis is likely to lead to the development of tuberculosis that is resistant both to Rifabutin and to rifampin. There is no evidence that Rifabutin is an effective prophylaxis against M. tuberculosis . Patients requiring prophylaxis against both M. tuberculosis and Mycobacterium avium complex may be given isoniazid and Rifabutin concurrently. CONTRAINDICATIONS Rifabutin Capsules are contraindicated in patients who have had clinically significant hypersensitivity to rifabutin or to any other rifamycins.

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Medical Disclaimer

This drug information is for educational purposes only and should not replace professional medical advice. Drug information is sourced from the FDA National Drug Code Directory and Structured Product Labeling. Always consult with a healthcare provider before starting, stopping, or changing any medication.