Rifampicin is an antibiotic that works by interfering with the way a bacteria's DNA makes RNA. As such, it works against a wide range of bacterial infections. Ironically, the active ingredient was isolated from soil bacteria. It is commonly used to treat tuberculosis and latent meningitis.
However, if rifampicin is not used properly on a daily basis, drug resistance develops very quickly. As such, it is almost always used together with other antibiotics. It is one of the only drugs that is effective against MRSA.
It's main side effect is liver damage as the same mechanism that kills bacteria also increases the production of certain liver enzymes increasing the metabolism of the organ. As such, patients on the drug are routinely given liver function tests. It is also not recommended for women on the pill as it interferes with hormone regulation and can result in unintended pregnancy.
in addition, due to it's effect on the liver, it often increases the immediate effect of other medications while simultaneously shortening the amount of time they are effective.