A Cochrane review [Abstract] 1 included 31 studies with a total of 5 430 subjects. There is high quality of evidence that buprenorphine was superior to placebo medication in retention of participants in treatment at all doses examined. There is moderate quality of evidence that high-dose buprenorphine (HASH(0x2fd8c80) 16 mg) was more effective than placebo in suppressing illicit opioid use measured by urinanalysis (SMD -1.17; 95% CI -1.85 to -0.4; 3 trials, n=729). Low-dose and medium-dose buprenorphine did not suppress illicit opioid use measured by urinanalysis better than placebo. Buprenorphine given in flexible doses appeared less effective than methadone in retaining patient in treatment (RR=0.83; 95% CI: 0.72 to 0.95, 5 trials, n=788). For those retained in treatment, no difference was observed in suppression of opioid use as measured by urinalysis (SMD -0.11; 95% CI -0.23 to 0.02; 8 studies, n=1027). There was no difference between medium-dose buprenorphine (7 - 15 mg) and medium-dose methadone (40 - 85 mg) in retention or in suppression of illicit opioid use as measured by urines, (SMD 0.25; 95% CI -0.08 to 0.58; 4 trials, n=476). Similarly, there was no difference between high-dose buprenorphine (HASH(0x2fd8c80) 16 mg) and high-dose methadone (HASH(0x2fd8c80) 85 mg) in retention or suppression of self-reported heroin use.
Another Cochrane review[Abstract]2 included 6 studies with a total of 607 subjects. There was no difference between methadone and buprenorphine in self reported opioid use (RR 0.37, 95% CI 0.08 to 1.63) or opioid positive urine drug tests (RR 0.81, 95% CI 0.56 to 1.18) in 2 trials. There was low quality evidence from 3 studies of no difference in retention between buprenorphine and methadone maintenance treatment (RR 0.69, 95% CI 0.39 to 1.22).
Comment: The quality of evidence is downgraded by study quality (unclear allocation concealment in majority of trials).
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