Drug for multidrug resistant TB approved Share This: UPI 1/1/2013 1:37:31 AM WASHINGTON, Dec. 31 (UPI) -- The U.S. Food and Drug Administration approved Sirturo, part of combination therapy to treat adults with multidrug resistant tuberculosis, officials say. Dr. Edward Cox, director of the Office of Antimicrobial Products in the FDA's Center for Drug Evaluation and Research, said multidrug resistant TB occurs when M. tuberculosis becomes resistant to isonazid and rifampin, two powerful drugs most commonly used to treat TB. Sirturo, or bedaquilinem, is the first drug approved to treat multidrug resistant TB and should be used in combination with other drugs used to treat TB. Sirturo works by inhibiting an enzyme needed by M. tuberculosis to replicate and spread throughout the body, Cox explained. "Multidrug resistant tuberculosis poses a serious health threat throughout the world, and Sirturo provides much-needed treatment for patients who have don't have other therapeutic options available," Cox said in a statement. "However, because the drug also carries some significant risks, doctors should make sure they use it appropriately and only in patients who don't have other treatment options." Sirturo was approved under the FDA's accelerated approval program, which allows the agency to approve a drug to treat a serious disease based on clinical data showing the drug has an effect on a surrogate endpoint that is reasonably likely to predict a clinical benefit to patients, Cox said. Additional studies will be conducted to confirm the drug's clinical benefit and safe use.