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Methadone maintenance interventions


Methadone has been around as a morphine-like opioid for about 50 years, and since the 1960s has been used as a type of legal opioid substitution therapy. This is a difficult area, and the question perennially seems to be 'why bother?'. A systematic review has sought to try and answer this difficult question.


A thorough search strategy sought out papers examining people with a diagnosis of opiate-dependent substance abuse without any concurrent psychiatric diagnosis. Experimental designs in which methadone maintenance was compared to control - heroin-dependent individuals not on methadone maintenance, and those having a pre-post design. Outcomes were illicit opiate use (by drug analysis and self-reporting), HIV risk behaviour, and various assessments of criminal behaviour.

Eleven studies were found, and it was demonstrated that different trial designs made no difference to outcomes. The results were presented in a highly statistical way, but they did display sufficient results to show the percentage of patients in the methadone maintenance programmes who decreased risk behaviours, and to compute a notional number needed to treat. These are shown in the Figure.

Figure: The percentage of individuals seeking treatment and remaining in a methadone maintenance programme who would demonstrate a reduction in various types of behaviour. Numbers at the end of the bars are the computed numbers needed to treat for one individual to benefit who would not benefit without treatment

For instance, illicit opiate use was reduced by 67% by methadone maintenance, with a NNT of 2.9. For drug-related criminal behaviour, 85% would be expected to reduce this, with a NNT of 1.4.


This is a very difficult study to follow. It does not give much information on trial design, and, for instance, gives only information on those people who stayed in the studies for six to 12 months and we are not given drop-out rates. The results may be applicable only to those opiate-dependent individuals who both seek treatment and remain in treatment. What we have here, though, is an important benchmark against which future treatments, like intravenous anaesthetic withdrawal, could be compared, and proper studies designed.


  1. LA Marsch. The efficacy of methadone maintenance interventions in reducing illicit opiate use, HIV risk behaviour and criminality: a meta-analysis. Addiction 1998 93: 515-32.
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