Rifampicin, also known as rifampin, is an antibiotic used to treat a several types of bacterial infections. This includes tuberculosis, leprosy, and Legionnaire's disease. It is almost always used along with other antibiotics, except when given to prevent Haemophilus influenzae type b and meningococcal disease in those who have been exposed to those bacteria. Before treating someone for a long period of time, measurement of liver enzymes and blood counts are recommended. It can be given either by mouth or intravenously. Common side effects include nausea, vomiting, diarrhea, and loss of appetite. It often turns urine, sweat, and tears a red or orange color. Liver problems or allergic reactions may occur. It is part of the recommended treatment of active tuberculosis during pregnancy, even though its safety in pregnancy is not known. Rifampicin is of the rifamycin group of antibiotics. It works by stopping the making of RNA by bacteria. Rifampicin was discovered in 1957 and first sold as a medication in 1971. It is on the World Health Organization's List of Essential Medicines, the most important medications needed in a basic health system. It is available as a generic medication. The wholesale cost in the developing world is about 3.90 USD a month. In the United States it is expensive with a month of treatment being about 120 USD. Rifampicin is made from Amycolatopsis rifamycinica.