Rifapentine
Rifapentine (Priftin)
Rifapentine
(rih-fah- PEN-teen)
Pregnancy Category: C Priftin (Rx)

Classification: Antituberculosis drug

Action/Kinetics: Similar activity to rifampin. Inhibits DNA-dependent RNA polymerase in susceptible strains of Mycobacterium tuberculosis, but not in mammalian cells. Is bactericidal against both intracellular and extracellular organisms. Food increases amount absorbed. Maximum levels: 5-6 hr. Steady state conditions: 10 days after 600 mg/day. Metabolized to the active 25-desacetyl rifapentine. Both the parent drug and active metabolite are significantly bound to plasma proteins. t 1/2: 13.2 hr for parent drug, 13.4 hr for active metabolite. Excreted in the feces (70%) and the urine (17%).

Uses: Treatment of pulmonary tuberculosis. Must be used with at least one other antituberculosis drug.

Contraindications: Hypersensitivity to other rifamycins (e.g., rifampin or rifabutin). Lactation.

Special Concerns: Experience is limited in HIV-infected clients. Organisms resistant to other rifamycins are likely to be resistant to rifapentine. Use with caution in clients with abnormal liver tests or liver disease. Safety and efficacy have not been determined in children less than 12 years of age.

Side Effects: Side effects listed occurred in 1% or more of clients and were seen when rifapentine was used in combination with other antituberculosis drugs (e.g., isoniazid, pyrazinamide, ethambutol). GI: N&V;, dyspepsia, diarrhea, hemoptysis. CNS: Anorexia, headache, dizziness. GU: Pyuria, proteinuria, hematuria, urinary casts. Dermatologic: Rash, acne, maculopapular rash. Hematologic: Neutropenia, lymphopenia, anemia, leukopenia, thrombocytosis. Miscellaneous: Hyperuricemia (probably due to pyrizinamide), hypertension, pruritus, arthralgia, pain, red coloration of body tissues and fluids.

Laboratory Test Alterations: ALT, AST. Inhibition of standard microbiological assays for serum folate and vitamin B ₁₂.

Drug Interactions: Cytochrome P450 / Rifapentine is an inducer of certain cytochromes P450 reduced activity of a number of drugs (See Rifampin). Dosage adjustment may be required Indinavir / Three-fold in clearance of indinavir.

How Supplied: Tablets: 150 mg

Dosage
?Tablets Tuberculosis, intensive phase.
600 mg (four 150 mg tablets) twice weekly with an interval of 72 hr or more between doses continued for 2 months.
Tuberculosis, continuation phase
Continue rifapentine therapy once weekly for 4 months in combination with isoniazid or another antituberculosis drug. If the client is still sputum-smear- or culture-positive, if resistant organisms are present, or if the client is HIV-positive, follow ATS/CDC treatment guidelines.