Rifapentine

Rifapentine (RPT), sold under the brand name Priftin, is an antibiotic used in the treatment of tuberculosis. In active tuberculosis it is used together with other antituberculosis medications. In latent tuberculosis it is typically used with isoniazid. It is taken by mouth. Rifapentine (RPT), sold under the brand name Priftin, is an antibiotic used in the treatment of tuberculosis. In active tuberculosis it is used together with other antituberculosis medications. In latent tuberculosis it is typically used with isoniazid. It is taken by mouth. Common side effects include low neutrophil counts in the blood, elevated liver enzymes, and white blood cells in the urine. Serious side effects may include liver problems or Clostridium difficile associated diarrhea. It is unclear if use during pregnancy is safe. Rifapentine is in the rifamycin family of medication and works by blocking DNA-dependent RNA polymerase. Rifapentine was approved for medical use in the United States in 1998. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. In the United States it costs $100–200 per month. In many areas of the world it is not easy to get as of 2015. A review of alternative regimens for prevention of active tuberculosis in HIV-negative individuals with latent TB found that a weekly, directly observed regimen of rifapentine with isoniazid for three months was as effective as a daily, self -administered regimen of isoniazid for nine months. But the rifapentine-isoniazid regimen had higher rates of treatment completion and lower rates of hepatotoxicity. However, the rate of treatment-limiting adverse events was higher in the rifapentine-isoniazid regimen. Rifapentine has been assigned a Pregnancy Category C by the FDA. Rifapentine in pregnant women has not been studied, but animal reproduction studies have resulted in fetal harm and were teratogenic. If rifapentine and rifampin are used together in pregnancy, coagulation should be monitored due to a possible increased risk of maternal postpartum hemorrhage and infant bleeding. Common side effects are hyperuricemia, pyuria, hematuria, urinary tract infection, proteinuria, neutropenia, anemia, and hypoglycemia. Rifapentine should be avoided in patients with an allergy to the rifamycin class of drugs. This drug class includes rifampicin and rifabutin. Rifapentine induces metabolism by CYP3A4, CYP2C8 and CYP2C9 enzymes. It may be necessary to adjust the dosage of drugs metabolized by these enzymes if they are taken with rifapentine. Examples of drugs that may be affected by rifapentine include warfarin, propranolol, digoxin, protease inhibitors and oral contraceptives. The chemical structure of rifapentine is similar to that of rifamycin, with the notable substitution of a methyl group for a cyclopentane (C5H9) group.