What is Rifadin?

Rifampicin (INN, BAN) or rifampin (USAN) is a bactericidal antibiotic drug of the rifamycin group.

Rifampicin inhibits bacterial DNA-dependent RNA synthesis by inhibiting bacterial DNA-dependent RNA polymerase. Rifampicin may be abbreviated R, RMP, RA, RF, or RIF (US).

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 Prof. Piero Sensi (1920-2013) and Dr. Maria Teresa Timbal (1925 - 1969) discovered a new bacterium. This new species appeared immediately of great scientific interest since it was producing 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 1959 and was named "rifampicin".

Rifampicin is also known as rifaldazine, RMP, rofact (in Canada), and rifampin in the United States. There are various types of rifamycins from which this is derived, but the rifampicin form, with a 4-methyl-1-piperazinaminyl group, is by far the most clinically effective. Rifampicin can also be derived from rifamycin S.

Rifampicin is an intensely red solid, and the small fraction which reaches body fluids is known for imparting a harmless red-orange color to the urine (and to a lesser extent, also sweat and tears) of users, for a few hours after a dose. Maximal concentrations in the blood are decreased by about a third when the antibiotic is taken with food.