This is a 19-week, multi-center, parallel group study that includes: 1) up to 3 weeks for screening; 2) a 13-week Treatment Phase consisting of a 1-week, single-blind run-in period, when all subjects receive twice daily 15 mg acetazolamide capsules (a medication adherence marker), followed by randomization to either twice daily 10 mg lorcaserin or placebo capsules for the remaining 12 weeks; and 3) a 3-week follow-up period, with scheduled visits during Study Weeks 14 and 16.

This study will use a randomized controlled trial design, in which PCCs will be randomized to receive one of two trainings delivered via MyLearning: a stigma reduction training or an attention control training. Outcome assessments will occur immediately following the training delivery (PCC initial survey), at 3 months following training completion (PCC follow-up survey), and in the 6 months following the training (objective indicators of PCC Opioid Wizard use, waivered clinician prescribing behavior, and waiver status).

This is an open-label, randomized, pilot trial of XR-NTX vs. treatment as usual (TAU) for treatment of opioid and alcohol use disorders in HIV-infected patients, whose goal is to determine the acceptability and feasibility of XR-NTX in HIV practice and inform development of a multi-site comparative effectiveness trial of XR-NTX vs. TAU in HIV clinics. During the study start-up period, we will conduct a survey of HIV provider attitudes toward opioid antagonist therapy at 15 high-volume HIV clinics to assess willingness to prescribe antagonist therapy and inform the site selection process (Aim 1). During pilot study implementation, we will survey HIV-infected patients regarding attitudes toward opioid antagonist therapy (Aim 2), track rate of participant recruitment (Aim 3), and randomize those who have untreated opioid and/or alcohol use disorders to receive XR-NTX vs. TAU (Aim 4). Participants will attend study visits every 4 weeks for 16 weeks. Treatment initiation will be assessed at 4 weeks and retention at 16 weeks (4 XR-NTX injections). Randomization will continue until a maximum of 50 participants or 12 months are reached. Pilot study duration will be a maximum of 17 months (maximum 12 months recruitment + 5 months study participation for those enrolled at the end of the recruitment period). We will assess feasibility of a multi-site trial of XR-NTX vs. TAU by addressing four pilot study specific aims.