An overview of systematic reviews of the effectiveness of opiate maintenance therapies: available evidence to inform clinical practice and research

Aim: To summarize the major findings of the five Cochrane reviews on substitution maintenance treatments for opioid dependence. Methods: We conducted a narrative and quantitative summary of systematic review findings. There were 52 studies included in the original reviews (12,075 participants, range 577-5894): methadone maintenance treatment (MMT) was compared with methadone detoxification treatment (MDT), no treatment, different dosages of MMT, buprenorphine maintenance treatment (BMT), heroin maintenance treatment (HMT), and l-α-acetylmethadol (LAAM) maintenance treatment (LMT). Measurements: Outcomes considered were retention in treatment, use of heroin and other drugs during treatment, mortality, criminal activity, and quality of life. Findings: Retention in treatment: MMT is more effective than MDT, no treatment, BMT, LMT, and heroin plus methadone. MMT proved to be less effective than injected heroin alone. High doses of methadone are more effective than medium and low doses. Use of heroin: MMT is more effective than waiting list, less effective than LAAM, and not different from injected heroin. No significant results were available for mortality and criminal activity. Conclusions: These findings confirm that MMT at appropriate doses is the most effective in retaining patients in treatment and suppressing heroin use but show weak evidence of effectiveness toward other relevant outcomes. Future clinical trials should collect data on a broad range of health outcomes and recruit participants from heterogeneous practice settings and social contexts to increase generalizability of results.