This is a double blind, double-dummy, placebo controlled, randomized trial of a 48-week course of implant naltrexone vs. oral naltrexone, each arm with drug counseling every two weeks, for 200 HIV+ patients who are in early remission from opioid dependence, and who are interested in relapse prevention treatment medication, and starting their first episode of antiretroviral therapy at the Botkin Infectious Disease Hospital in St. Petersburg or the Leningrad Regional AIDS Center. Early remission was chosen because relapse risk is the highest at this point, thus maximizing the chances for detecting a naltrexone effect. The first antiretroviral therapy treatment episode was chosen because it is feasible (relatively few opioid addicted Russians have been treated with antiretroviral therapy), and because the virus is less likely to have developed secondary resistance.