Comparison of methadone and buprenorphine for opiate detoxification (LEEDS trial) : a randomised controlled trial

Background: Many opiate users require prescribed medication to help them achieve abstinence, commonly taking the form of a detoxification regime. In UK prisons, drug users are nearly universally treated for their opiate use by primary care clinicians, and once released access GP services where 40% of practices now treat drug users. There is a paucity of evidence evaluating methadone and buprenorphine (the two most commonly prescribed agents in the UK) for opiate detoxification. Aim: To evaluate whether buprenorphine or methadone help to achieve drug abstinence at completion of a reducing regimen for heroin users presenting to UK prison health care for detoxification. Design: Open-label, pragmatic, randomised controlled trial in three prison primary healthcare departments in the north of England. Method: Prisoners (n = 306) using illicit opiates were recruited and given daily sublingual buprenorphine or oral methadone, in the context of routine care, over a standard reduced regimen of not more than 20 days. The primary outcome measure was abstinence from illicit opiates at 8 days post detoxification, as indicated by urine test (self-report/clinical notes where urine sample was not feasible). Secondary outcomes were also recorded. Results: Abstinence was ascertained for 73.7% at 8 days post detoxification (urine sample = 52.6%, self report = 15.2%, clinical notes = 5.9%). There was no statistically significant difference in the odds of achieving abstinence between methadone and buprenorphine (odds ratio [OR] = 1.69; 95% confidence interval [CI] = 0.81 to 3.51; P = 0.163). Abstinence was associated solely with whether or not the participant was still in prison at that time (15.22 times the odds; 95%CI = 4.19 to 55.28). The strongest association for lasting abstinence was abstinence at an earlier time point. Conclusion: There is equal clinical effectiveness between methadone and buprenorphine in achieving abstinence from opiates at 8 days post detoxification within prison.