Medical treatments for opioid use disorder in Iran: a randomized, double-blind placebo-controlled comparison of buprenorphine/naloxone and naltrexone maintenance treatment

AimsWith the broad goals of developing a clinical research and training program and disseminating effective opioid use disorder treatments in Iran, this pilot clinical trial compared the effectiveness of oral naltrexone (NTX) and sublingual buprenorphine/naloxone (BNX). DesignTwelve-week single-site, two-group parallel randomized double-blind clinical trial. SettingAn out-patient clinical research program in Tehran, Iran. ParticipantsFollowing medically assisted withdrawal, participants with opioid use disorder were assigned randomly to NTX (n=51) or BNX (n=51). InterventionMedications were administered three times per week, double-blind, double-dummy for 12weeks. All participants received weekly group drug counseling. MeasurementsThe primary outcome was initial duration of opioid abstinence verified by urine toxicology tests. Secondary outcomes included the number of opioid-negative urine tests, treatment retention and proportions with sustained, verified opioid-abstinence for 12weeks. FindingsMean [95% confidence interval (CI)] number of days of initial duration of verified abstinence was 28.8 (20.0-37.5) with BNX and 21.6 (14.4-28.7) with NTX (P=0.205). The mean (95% CI) number of opioid-negative urine tests was 19.7 (17.7-21.6) with BNX and 15.4 (13.1-17.8) with NTX (P=0.049). The mean (95% CI) number of days in treatment was 70.6 (63.6-77.7) with BNX versus 56.5 (47.8-65.3) with NTX (P=0.013). The rate of sustained, 12-week opioid abstinence was 16% (8/51) in the BNX group and 8% (4/51) in the NTX group (P=0.219). ConclusionsAmong patients with opioid use disorder in Iran, sublingual buprenorphine/naloxone was associated with a greater number of opioid-negative urine tests and treatment retention than oral naltrexone, but not significantly greater initial abstinence duration or proportions with sustained abstinence.