<prompt> Which of the following drug used in treating leprosy acts as a bactericidal agent?ClofazimineDapsoneRifampicinEthionamide  <response>: Dapsone, rifampicin and clofazimine are WHO recommended drugs used in the treatment of leprosy. Among these only rifampicin is bactericidal. Rifampin binds to the beta subunit of bacterial DNA-dependent RNA polymerase and thereby inhibits RNA synthesis. It is bactericidal, it penetrates most tissues and into phagocytic cells. Indications: Treatment of tuberculosis along with other antimycobacterial drugs. Used to eliminate meningococcal carriage Leprosy Prophylaxis in contacts of children with Haemophilus influenzae type b disease In combination with a second agent is used to eradicate staphylococcal carriage In serious staphylococcal infections such as osteomyelitis and prosthetic valve endocarditis Ref: Gelber R.H. 2012. Chapter 166. Leprosy. In D.L. Longo, A.S. Fauci, D.L. Kasper, S.L. Hauser, J.L. Jameson, J. Loscalzo Eds, Harrisons Principles of Internal Medicine, 18e. 