About Rifampicin Rifamycin derivative, Antituberculosis antibiotic. Mechanism of Action of Rifampicin Rifampicin is primarily bactericidal and has some bacteriostatic properties also. It acts by inhibiting DNA dependent RNA polymerase and thus stopping the expression of bacterial genes.M.tuberculosis requires DNA dependent RNA polymerase enzyme for the synthesis of RNA and protein. Without this enzyme bacteria cannot reproduce and they die. Indications for Rifampicin 1. Leprosy 2. Tuberculosis 3. Prophylaxis of meningococcal carriers 4. Prophylaxis of H. influenzae Interactions for Rifampicin Rifampicin by inducing the hepatic microsomal enzymes may reduce the efficacy of the following drugs: Acetaminophen, oral anticoagulants, barbiturates, benzodiazepines, chloramphenicol, clofibrate. Oral contraceptives, corticosteroids, cyclosporine, digitoxin, disopyramide, beta blockers oestrogens, hydantoins, mexiletine, quinidine, sulfones, sulphonylureas, theophylline, verapamil