Rifampicin, also known as rifampin, is an antibiotic used to treat several types of bacterial infections, including tuberculosis, Mycobacterium avium complex, leprosy, and Legionnaires’ disease.^[2] It is almost always used together with other antibiotics, except when given to prevent Haemophilus influenzae type b and meningococcal disease in people who have been exposed to those bacteria.^[2] Before treating a person for a long period of time, measurements of liver enzymes and blood counts are recommended.^[2] Rifampicin may be given either by mouth or intravenously.^[2]

Common side effects include nausea, vomiting, diarrhea, and loss of appetite.^[2] It often turns urine, sweat, and tears a red or orange color.^[2] Liver problems or allergic reactions may occur.^[2] It is part of the recommended treatment of active tuberculosis during pregnancy, though its safety in pregnancy is not known.^[2] Rifampicin is of the rifamycin group of antibiotics.^[2] It works by stopping the production of RNA by bacteria.^[2]

Rifampicin was discovered in 1965, marketed in Italy in 1968, and approved in the United States in 1971.^[3][4][5] It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system.^[6] It is available as a generic medication.^[2] The wholesale cost in the developing world is about US$3.90 a month.^[7] In the United States a month of treatment is about $120.^[2][8] Rifampicin is made by the soil bacterium Amycolatopsis rifamycinica.^[5]