Anti-retroviral Therapy, Medications for Opioid Use Disorder, Opioids and HIV Infection - Study 1

Inclusion Criteria: * Meet DSM-5 criteria for moderate to severe opiate use disorder (as determined by DSM-5 checklist) * Opiate use with a positive urine drug screen for heroin or other opiates (other than methadone, buprenorphine, buprenorphine/naloxone) at screening visit * Documented HIV-1 infection with CD4 less than 350 cells/ μL and VL more than 10,000 copies/mL * cART-naïve or or on cART no longer than 3 months if already started * Willingness to receive cART or on cART no longer than 3 months if already started * Willingness to be randomized to either daily methadone, buprenorphine/naloxone or monthly injection of extended-release naltrexone treatment * Ability to understand and complete study procedures * Provision of adequate locator information that lists all contact information a participant agrees that the research staff may use to reach him/her * All participants must be able to comprehend the purpose of the study and to provide informed consent * Is, in the opinion of the study physician, in stable health as determined by pre-study physical examination, medical history, ECG, and laboratory evaluations and is likely to complete the study. * Has a total body weight of more than 50 kg (110 pounds) and a body mass index (BMI) of more than 20 at screening. * Female subjects: Cannot be pregnant, Cannot be lactating, Must be unable to conceive (i.e., surgically sterilized, sterile, or post-menopausal defined as 1 year without bleeding or spotting) OR must agree to u…