Also found in: Dictionary, Wikipedia.
Pharmacologic class: Rifamycin derivative
Therapeutic class: Antimycobacterial
Pregnancy risk category B
Inhibits RNA synthesis by blocking RNA transcription in susceptible organisms (mycobacteria and some gram-positive and gram-negative bacteria)
Capsules: 150 mg
Indications and dosages
➣ To prevent disseminated Mycobacterium avium intracellulare complex in patients with advanced human immunodeficiency virus (HIV) infection
Adults: 300 mg P.O. daily as a single dose or in two divided doses
• Prophylaxis and treatment of M. avium intracellulare in children
• Hypersensitivity to drug
• Active tuberculosis
Use cautiously in:
• severe hepatic disease
• pregnant or breastfeeding patients.
• Give in divided doses twice daily with food to reduce GI upset.
CNS: headache, asthenia, weakness
CV: pressure sensation in chest
EENT: uveitis; discolored tears, saliva, or sputum
GI: nausea, vomiting, diarrhea, dyspepsia, abdominal pain, eructation, flatulence, discolored feces, anorexia
GU: discolored urine
Hematologic: eosinophilia, neutropenia, leukopenia, thrombocytopenia Musculoskeletal: joint pain, myalgia
Skin: rash, discolored skin or sweat
Other: abnormal taste, fever, flulike symptoms
Drug-drug. Clarithromycin, itraconazole, saquinavir: reduced blood levels and efficacy of these drugs
Delavirdine: decreased delavirdine blood level, increased rifabutin blood level
Drugs metabolized by liver (such as zidovudine): altered blood levels of these drugs
Hormonal contraceptives: decreased contraceptive efficacy
Indinavir, nelfinavir, ritonavir: increased rifabutin blood level
Drug-diagnostic tests. Alanine aminotransferase, aspartate aminotransferase, eosinophils: increased levels
Neutrophils, platelets, white blood cells: decreased counts
Drug-food. High-fat foods: delayed drug absorption
• Monitor CBC with white cell differential. Watch for signs and symptoms of blood dyscrasias.
• Assess nutritional status.
• Closely monitor vital signs and temperature. Stay alert for dyspnea and flulike symptoms.
• Advise patient to take twice daily with food (but not high-fat food) if GI upset occurs. To further minimize GI upset, teach him to eat small, frequent servings of healthy food and drink plenty of fluids.
• Instruct patient to take exactly as prescribed, even after symptoms subside.
☞ Tell patient to immediately report easy bruising or bleeding.
• Tell patient drug may turn tears, urine, and other body fluids reddish or brownish orange. Instruct him not to wear contact lenses during therapy because drug may stain them permanently.
• Inform patient that drug occasionally causes eye inflammation. Instruct him to report symptoms promptly.
• Caution patient to avoid driving and other hazardous activities until effects of drug are known.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, and foods mentioned above.