No one knows when to start antiretroviral drugs in people with HIV and tuberculosis. Delaying ARVs is often done, for fear of drug toxicity and interactions, as well as immune reconstitution syndrome (dangerous worsening of the inflammatory response to TB as the immune system recovers). Of course, that means the HIV gets to continue its nasty replicative business, chemically unopposed.
Blanc et al may have settled the question. They randomized 661 people in Cambodia with HIV-AIDS (CD4 < 200, with half < 25) and newly diagnosed tuberculosis to receive antiretroviral treatment beginning at 2 weeks, or 8 weeks (CAMELIA trial). They followed them for ~2 years.
Those starting ARVs earlier had a hazard ratio of 0.62 for dying (18% vs. 27% in the later-initiation group). This was despite a significantly higher rate of immune reconstitution syndrome (IRIS) in the early-treatment group (hazard ratio 2.5). Both groups responded well to ARV treatment, with CD4 counts climbing to > 114 in more than half, and an undetectable viral load at one year in 97% of the patients.
Blanc F-X et al. Earlier versus Later Start of Antiretroviral Therapy in HIV-Infected Adults with Tuberculosis. N Engl J Med 2011;365:1471-1481.