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Rifabutin
Rifabutin (Mycobutin)
Rifabutin
(rif-ah-BYOU-tin)
Pregnancy Category: B
Mycobutin
(Rx)
Classification:
Antitubercular drug
Action/Kinetics:
Inhibits DNA-dependent RNA polymerase in susceptible strains of Escherichia coli and Bacillus subtilis. Rapidly absorbed from the GI tract. Peak plasma levels after a single dose: 3.3 hr. Mean terminal t1/2: 45 hr. About 85% is bound to plasma proteins. High-fat meals slow the rate, but not the extent, of absorption. About 30% of a dose is excreted in the feces and 53% in the urine, primarily as metabolites. The 25-O-desacetyl metabolite is equal in activity to rifabutin.
Uses:
Prevention of disseminated Mycobacterium avium complex (MAC) disease in clients with advanced HIV infection.
Contraindications:
Hypersensitivity to rifabutin or other rifamycins (e.g., rifampin). Use in active tuberculosis. Lactation.
Special Concerns:
Safety and efficacy have not been determined in children, although the drug has been used in HIV-positive children.
Side Effects:
GI: Anorexia, abdominal pain, diarrhea, dyspepsia, eructation, flatulence, N&V;, taste perversion. Respiratory: Chest pain, chest pressure or pain with dyspnea. CNS: Insomnia, seizures paresthesia, aphasia, confusion. Musculoskeletal: Asthenia, myalgia, arthralgia, myositis. Body as a whole: Fever, headache, generalized pain, flu-like syndrome. Dermatologic: Rash, skin discoloration. Hematologic: Neutropenia, leukopenia, anemia, eosinophilia, thrombocytopenia. Miscellaneous: Discolored urine, nonspecific T wave changes on ECG, hepatitis, hemolysis, uveitis.
Laboratory Test Alterations:
AST, ALT, alkaline phosphatase.
Overdose Management:
Symptoms: Worsening of side effects. Treatment: Gastric lavage followed by instillation into the stomach of an activated charcoal slurry.
Drug Interactions:
Although less potent than rifampin, rifabutin induces liver enzymes and may be expected to have similar interactions as does rifampin.
- AZT / AZT steady-state plasma levels after repeated rifabutin dosing
- Oral contraceptives / May OC effectiveness
How Supplied:
Capsule: 150 mg
Dosage
•Capsules
Prophylaxis of MAC disease in clients with advanced HIV infection.
Adults: 300 mg/day.
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