Rifampicin, also known as rifampin, is an ansamycin antibiotic used to treat several types of bacterial infections, including tuberculosis (TB), Mycobacterium avium complex, leprosy, and Legionnaires’ disease. It is almost always used together with other antibiotics with two notable exceptions: when given as a "preferred treatment that is strongly recommended" for latent TB infection; and when used as post-exposure prophylaxis to prevent Haemophilus influenzae type b and meningococcal disease in people who have been exposed to those bacteria. Before treating a person for a long period of time, measurements of liver enzymes and blood counts are recommended. Rifampicin may 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,  though its safety in pregnancy is not known. Rifampicin is of the rifamycin group of antibiotics. It works by decreasing the production of RNA by bacteria.Rifampicin was discovered in 1965, marketed in Italy in 1968, and approved in the United States in 1971. It is on the World Health Organizations List of Essential Medicines. The World Health Organization classifies rifampicin as critically important for human medicine. It is available as a generic medication. Rifampicin is made by the soil bacterium Amycolatopsis rifamycinica. Medical uses
Mycobacteria
Rifampicin is used for the treatment of tuberculosis in combination with other antibiotics, such as pyrazinamide, isoniazid, and ethambutol.
Use in biotechnology
Rifampicin inhibits bacterial RNA polymerase, thus it is commonly used to inhibit the synthesis of host bacterial proteins during recombinant protein expression in bacteria. RNA encoding for the recombinant gene is usually transcribed from DNA by a viral T7 RNA polymerase, which is not affected by rifampicin. History
In 1957, a soil sample from a pine forest on the French Riviera was brought for analysis to the Lepetit Pharmaceuticals research lab in Milan, Italy. There, a research group headed by Piero Sensi and Maria Teresa Timbal discovered a new bacterium. This new species produced a new class of molecules with antibiotic activity. Because Sensi, Timbal and the researchers were particularly fond of the French crime story Rififi (about a jewel heist and rival gangs), they decided to call these compounds rifamycins. After two years of attempts to obtain more stable semisynthetic products, a new molecule with high efficacy and good tolerability was produced in 1965 and was named rifampicin.Rifampicin was first sold in Italy in 1968 and was approved by the FDA in 1971. Society and culture
Cancer-causing impurities
In August 2020, the U.S. Food and Drug Administration (FDA) became aware of nitrosamine impurities in certain samples of rifampin. The FDA and manufacturers are investigating the origin of these impurities in rifampin, and the agency is developing testing methods for regulators and industry to detect the 1-methyl-4-nitrosopiperazine (MNP).