Buprenorphine vs. Methadone for Opioid Use Disorders: Long-term Outcomes
- Most long-term follow-up studies of individuals with opioid use disorder are based on participants recruited from methadone maintenance treatment (MET), and results have generally shown positive outcomes in reduced opioid use and mortality.
- Currently, however, only very limited information is available on the long-term outcomes of participants started on buprenorphine (BUP) treatment, particularly relative to those receiving MET treatment.
This study, NIDA Clinical Trials Network protocol CTN-0050, is a long-term follow-up of patients from CTN-0027, Starting Treatment with Agonist Replacement Therapy (START), aimed at comparing outcomes over a period of 60 months among participants randomized to buprenorphine (BUP) or methadone (MET).
Findings revealed no difference in mortality between the two groups, with 23 (3.6%) of 630 participants on BUP having died, versus 26 (5.8%) of 450 randomized to MET. Opioid use at follow-up was higher among participants randomized to BUP relative to MET (42.8% to 31.7% positive opioid urine; 5.8 days vs. 4.4 days of past 30-day heroin use).
Opioid use over the duration of the follow-up period by randomized condition was also significant, mostly due to less treatment participation among those randomized to BUP compared to MET. Less opioid use was associated with both buprenorphine and methadone treatment (relative to no treatment), with no difference found. Individuals who were white or used cocaine at baseline responded better to methadone than to buprenorphine.
Conclusions: There 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. This study, the first to follow opioid dependent individuals randomized to two opioid maintenance treatments prospectively over 5 or more years, is instructive about longer term outcomes and poses a challenge to the field to enhance retention in the opioid maintenance treatment.
Many individuals with opioid use disorder cycle in and out of maintenance treatment, and this study confirms they show better outcomes when retained instead.Efforts are needed, especially in the context of the current opioid epidemic, to improve both BUP and MET treatment retention.