Long-term outcomes after randomization to buprenorphine/naloxone versus methadone in a multi-site trial

AimsTo compare long-term outcomes among participants randomized to buprenorphine or methadone. Design, Setting and ParticipantsFollow-up was conducted in 2011-14 of 1080 opioid-dependent participants entering seven opioid treatment programs in the United States between 2006 and 2009 and randomized (within each program) to receive open-label buprenorphine/naloxone or methadone for up to 24weeks; 795 participants completed in-person interviews (similar to 74% follow-up interview rate) covering on average 4.5years. MeasurementsOutcomes were indicated by mortality and opioid use. Covariates included demographics, site, cocaine use and treatment experiences. FindingsMortality was not different between the two randomized conditions, with 23 (3.6%) of 630 participants randomized to buprenorphine having died versus 26 (5.8%) of 450 participants randomized to methadone. Opioid use at follow-up was higher among participants randomized to buprenorphine relative to methadone [42.8 versus 31.7% positive opioid urine specimens, P<0.01, effect size (h)=0.23 (0.09, 0.38); 5.8days versus 4.4days of past 30-day heroin use, P<0.05, effect size (d)=0.14 (0.00, 0.28)]. Opioid use during the follow-up period by randomization condition was also significant (F-(7,F-39600)=3.16; P<0.001) due mainly to less treatment participation among participants randomized to buprenorphine than methadone. Less opioid use was associated with both buprenorphine and methadone treatment (relative to no treatment); no difference was found between the two treatments. Individuals who are white or used cocaine at baseline responded better to methadone than to buprenorphine. ConclusionsThere are few differences in long-term outcomes between buprenorphine and methadone treatment for opioid dependence, and treatment with each medication is associated with a strong reduction in opioid use.