Isoniazid for HIV-TB Coinfection Could Spur MDR-TB, Study Says

The antibiotic isoniazid, which is used to prevent the progression of active tuberculosis in HIV-positive people, could facilitate the development multi-drug resistant TB, according to a study scheduled to be published in the May 2 edition of the Proceedings of the National Academy of Sciences, SciDev.net reports. The World Health Organization recommends isoniazid for people living with both HIV and TB to prevent latent TB from becoming active. Ted Cohen of the Harvard School of Public Health and colleagues developed a mathematical model that predicted isoniazid use would reduce TB prevalence and mortality for several years but also would accelerate the development of MDR-TB. Cohen said the drug should be used in combination with methods to detect and treat MDR-TB (Ngandwe, SciDev.net, 4/20). "We're not saying isoniazid preventive therapy policies are ill-advised, but we think they need to be coupled with an understanding that large-scale IPT programs should be ready to diagnose and treat individuals with drug-resistant TB as part of the programs," Cohen said. NIH supported the research (Harvard School of Public Health release, 4/17).