For which patients or under which circumstances do you recommend a 9-month over a 6-month course of isoniazid for treatment of LTBI?  

The preferred regimens now for the treatment of latent TB infection are shorter rifamycin-based regimens. We have options of 3 months of isoniazid and rifapentine given once weekly, or 4 months of rifampin given daily, or 3 months of isoniazid and rifampin given daily. Isoniazid-only regimens are n...