Classifications: antituberculosis agent; antibiotic; Therapeutic: antibiotic; antituberculosis
Pregnancy Category: B
150 mg capsules
Semisynthetic bacteriostatic antibiotic. Mode of action may be to inhibit DNA-dependent RNA polymerase in susceptible bacterial
cells but not in human cells.
Effective against Mycobacterium avium complex (MAC) (or M. avium-intracellulare) and many strains of M. tuberculosis.
The prevention of disseminated Mycobacterium avium complex (MAC) disease in patients with advanced HIV infection.
Hypersensitivity to rifabutin or any other rifamycins; lactation.
Pregnancy (category B); older adults.
Route & Dosage
|Prevention of MAC
Adult: PO 300 mg q.d., may give 150 mg b.i.d. if nausea is a problem
Child: PO 75 mg q.d.
- Give as usual dose of 300 mg/d or in two divided doses of 150 mg with food if needed to reduce GI upset.
- Store at room temperature, 15°30° C (59°86° F), unless otherwise directed.
Adverse Effects (≥1%)CNS: Headache. GI: Abdominal pain, dyspepsia, nausea, taste perversion, increased liver enzymes. Hematologic: Thrombocytopenia
, eosinophilia, leukopenia
, neutropenia. Skin:
Rash. Other: Turns urine, feces, saliva, sputum, perspiration, and tears orange. Soft contact lenses may be permanently discolored.
May decrease levels of benzodiazepines
, beta blockers
, clofibrate, dapsone, narcotics
, cyclosporine, quinidine, oral contraceptives
, ketoconazole, fluconazole, barbiturates
, resulting in therapeutic failure.
1220% of oral dose reaches the systemic circulation. Peak:
23 h. Distribution:
85% protein bound. Widely distributed, high concentrations in the lungs, liver, spleen, eyes, and kidney. Crosses placenta,
distributed into breast milk. Metabolism:
In the liver. Causes induction of hepatic
Approximately 53% of dose is excreted in urine as metabolites, 30% is excreted in feces. Half-Life:
1696 h (average 45 h).
Assessment & Drug Effects
- Monitor patients for S&S of active TB. Report immediately.
- Lab tests: Monitor periodic blood work for neutropenia and thrombocytopenia.
- Evaluate patients on concurrent oral hypoglycemic therapy for loss of glycemic control.
- Review patient's complete drug regimen because dosage adjustment of a significant number of drugs may be needed when rifabutin
is added to regimen.
Patient & Family Education
- Learn S&S of TB and MAC (e.g., persistent fever, progressive weight loss, anorexia, night sweats, diarrhea) and notify physician
if any of these develop.
- Notify physician of following: Muscle or joint pain, eye pain or other discomfort, chest pain with dyspnea, rash, or a flu-like
- Be aware that urine, feces, saliva, sputum, perspiration, tears, and skin may be colored brown-orange. Soft contact lens
may be permanently discolored.
- Rifabutin may reduce the activity of a wide variety of drugs. Provide a complete and accurate list of concurrent drugs to
the physician for evaluation.