[3] Rifapentine is in the rifamycin family of medication and works by blocking DNA-dependent RNA polymerase.

[5] Common side effects include allergic reaction, anemia, neutropenia, elevated transaminases,[2] and pyuria.

Examples of drugs that may be affected by rifapentine include warfarin, propranolol, digoxin, protease inhibitors and birth control pills.

In August 2020, the U.S. Food and Drug Administration (FDA) became aware of nitrosamine impurities in certain samples of rifapentine.

[11] The FDA and manufacturers are investigating the origin of these impurities in rifapentine, and the agency is developing testing methods for regulators and industry to detect the 1-cyclopentyl-4-nitrosopiperazine (CPNP).

[11] As of January 2021, the FDA continues to investigate the presence of 1-methyl-4-nitrosopiperazine (MNP) in rifampin or 1-cyclopentyl-4-nitrosopiperazine (CPNP) in rifapentine approved for sale in the US.