Rifapentine

A to Z Drug Facts

 Action Inhibits DNA-dependent RNA polymerase in susceptible strains of Mycobacterium tuberculosis. Bactericidal for intracellular and extracellular M. tuberculosis organisms.

 Indications Treatment of pulmonary tuberculosis in conjunction with ³ 1 other antituberculosis drug to which the isolate is susceptible.

 Contraindications Hypersensitivity to any of the rifamycins (rifabutin, rifampin).

 Route/Dosage

ADULTS: PO Intensive phase: 600 mg twice weekly (with an interval of ³ 3 days) for 2 months. Continuation phase: 600 mg once weekly for 4 months. CHILDREN ³ 12 YR: PO Dosing should be similar to adult dosing.

 Interactions

Amitriptyline, azole antifungal agents, barbiturates, buspirone, chloramphenicol, clarithromycin, clofibrate, clozapine, oral contraceptives, corticosteroids, cyclosporine, dapsone, delavirdine, diazepam, digitalis glycosides, disopyramide, doxycycline, erythromycin, fluconazole, fluoroquinolones, haloperidol, indinavir, itraconazole, ketoconazole, levothyroxine, losartan, methadone, mexiletine, morphine, nelfinavir, nifedipine, nortriptyline, ondansetron, phenytoin, progestins, quinidine, quinine, ritonavir, saquinavir, sildenafil, sulfonylureas, tacrolimus, tamoxifen, theophylline, tocainide, toremifene, tricyclic antidepressants, troleandomycin, verapamil, warfarin, zidovudine, zolpidem: Has same interaction potential as rifampin. Potent inducer of hepatic drug metabolizing enzymes. Reduced levels and efficacy of target drugs may occur. Ketoconazole: May reduce rifapentine plasma levels, decreasing the therapeutic effects.

 Lab Test Interferences May alter microbiological assays for folate and vitamin B₁₂.

 Adverse Reactions

CV: Hypertension. CNS: Headache; dizziness. DERM: Rash; acne; pruritus. GI: Nausea; vomiting; dyspepsia; diarrhea; hemoptysis. GU: Pyuria; proteinuria; hematuria; urinary casts. HEMA: Neutropenia; lymphopenia; anemia; leukopenia; thrombocytosis. HEPA: Increased AST and ALT; hepatitis. OTHER: Anorexia; arthralgia; pain; hyperuricemia.

 Precautions

Pregnancy: Category C. Lactation: Undetermined. Children: Safety and efficacy in children < 12 yr not established. Body fluids: May produce a reddish-orange discoloration of the feces, urine, saliva, sweat, sputum, tears, and other body fluids. Contact lenses may become permanently discolored. Monitoring: Conduct baseline measurements of hepatic enzymes, bilirubin, CBC, and platelet counts. Question patients monthly concerning symptoms of adverse reactions. Follow up on abnormalities, including laboratory tests. Pseudomembranous colitis: Should be considered in patients in whom diarrhea develops.

 Administration/Storage

• Administer pyridoxine (vitamin B₆) concomitantly in patients who are malnourished, adolescent, and predisposed to neuropathy.
• If GI upset occurs or is anticipated, give drug with food.
• Store at room temperature. Protect from heat and humidity.

 Assessment/Interventions

• Obtain patient history, including drug history, history of noncompliance, and any known allergies.
• Assess for diarrhea with blood or pus, which may be a symptom of pseudomembranous colitis. Symptoms may occur after anti-infective treatment is completed.
• Avoid administration to pregnant or nursing women.
• Obtain baseline CBC, hepatic enzyme, and platelet counts.

 Patient/Family Education

• Provide patient information pamphlet.
• Instruct patient to take drug only as prescribed and for the full course of therapy.
• Inform patient that body fluids may turn reddish color, including urine, sweat, sputum, and tears, and that contact lenses may be permanently stained.
• Advise patient to take with food if prone to nausea, vomiting, or GI upset.
• Instruct patient to notify physician if any of the following symptoms are noted: Fever; anorexia; malaise; nausea; vomiting; dark urine; yellowed skin or eyes; pain or swelling of joints.
• Advise patients who are using oral contraceptives to use a nonhormonal form of contraception during therapy.

Books@Ovid
Copyright © 2003 Facts and Comparisons
David S. Tatro
A to Z Drug Facts