- Are either: 1) starting a new potent antiretroviral therapy for HIV; 2) enrolling in a potent antiretroviral trial; or 3) currently participating in an ongoing antiretroviral trial or in clinical care and will be changing treatment due to treatment failure. The entry visit for ACTG 736 must occur before starting the treatment or before changing to the new treatment. (This study has been changed to include patients who have changed treatment due to treatment failure and those who are starting a new anti-HIV regimen.)