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. It is almost always used together with other antibiotics with two notable exceptions when given as a second-line treatment for latent TB and 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.