Background: Dependent heroin users are characterised by the persistence of use in spite of the difficulties they experience with health, law, social achievements and personal relationships. The present review will consider maintenance treatment in which the patients enter programs of pharmacological administration tailored to achieve patient stabilisation. Many medications have been used for this purpose such as: Methadone, Buprenorphine and LAAM. The present review will focus on maintenance treatment through the prescription of heroin.
Objectives: To assess the efficacy and acceptability of heroin maintenance versus methadone or other substitution treatments for opioid dependence, in retaining patients in treatment; reducing the use of illicit substances and improving health and social functioning.
Search strategy: The Cochrane Central Register of Trials (CENTRAL) issue 4, 2002; MEDLINE (on Silver Platter) 1966-2002; EMBASE (on OVID) 1980-2000 and CINAHL till 2000 were searched. There was no language or publication year restrictions. Many researchers were contacted for information.
Selection criteria: Randomised controlled trials of heroin (alone or combined with methadone) maintenance treatment compared with any other pharmacological treatments.
Data collection and analysis: The trials were independently assessed for inclusion and methodological quality by the reviewers. Data were extracted independently and double checked. Studies were not pooled together because of heterogeneity.
Main results: 2400 references were obtained and 20 studies were eligible, 4 met the inclusion criteria for a total of 577 patients. The studies included could not be analysed cumulatively because of heterogeneity of interventions and outcomes considered. Two studies compared injected heroin to oral methadone for 1 year (270 patients) but considered different outcomes; one study compared injected heroin and methadone to oral methadone for 6 months (51 patients); and one compared inhaled heroin and methadone to oral methadone for 1 year (235 patients). Retention in treatment: in two studies there was no statistical difference between groups; one study (N=90) had a RR=2.49 (95% CI 1.51-4.10) in favour of heroin; one study (N=235) had a RR 0.79 (95%CI 0.68-0.90) in favour of methadone. Relapse to illegal heroin use, based on self report: in one study the proportion of people still using heroin were 64% in the heroin group, 59% methadone group; in the other study the RR was 0.33 (95%CI 0.15-0.72) in favour of heroin. The remaining studies did not provide the data. Criminal offence: one of the two studies which provided details about this showed the potential of heroin prescription in reducing the risk of being charged RR 0.32 (95% CI 0.14-0.78). Social functioning: the two studies reporting this outcome did not show statistical difference between intervention groups. The two most recent studies considered criminal offence and social functioning as part of a multidomain outcome measure and showed higher improvement among those treated with heroin plus methadone over those on methadone only.
Reviewer's conclusions: No definitive conclusions about the overall effectiveness of heroin prescription is possible because of non-comparability of the experimental studies available to be included in this review. Results favouring heroin treatment come from studies conducted in countries where the treatment system is comprehensive and easy accessible Methadone Maintenance Treatment at effective dosages is available. In those studies heroin prescription was addressed to patients who had failed previous methadone treatments.