12 December 1999

Could additional methadone increase cravings? 'Addiction' thinks so!

Curran HV, Bolton J, Wanigaratne S, Smyth C. 'Additional methadone increases craving for heroin: a double blind, placebo controlled study of chronic opiate users receiving methadone substitution treatment. Addiction 1999 94(5), 665-674

Rather than a useful contribution to the literature this small study confirms much of what is known about methadone behavioural pharmacology. It has one surprising finding of increased cravings in those given a one third extra methadone dose on one day, blind, with a week 'wash-out' period. This finding, being based on surveys of 18 patients and which, although statistically significant (p=0.03), was based on questions of a like nature concerning heroin craving on a small number of cases in a purely subjective area. This finding has been used in the title as though a highly important new finding despite a lack of further statitsical analysis possible and perhaps desirable on such series. The finding is out of keeping with much of what we know of methadone and the methods require closer scrutiny before being accepted. The reviewers had a difficult task as the findings would be considered controversial and rather outlandish by some.

While this is a little pedantic, I would also dispute the part of the title which states these are patients 'receiving methadone substitution treatment'. The text reveals that the patients were indeed on a treatment with a policy of 'reductions' and eventual abstinence rather than 'methadone substitution' which I use synonymously with 'maintenance'. According to the latest UK dependency guidelines, 'methadone substitution treatment' requires an effective dose of 60mg to 120mg with only exceptional cases needing less or more. These patients were not doing particularly well, judging by the frequent reported use of illicit drugs by the group. The authors state that the patients were chosen on the basis that they were on stable doses, but that the clinic had a policy of reductions to abstinence. In this cohort the average dose was 43mg, about half the level found in good quality methadone treatment services generally (and these include some patients on reductions). Hence these patients were either on inappropriate, ineffective 'methadone substitution' as defined by the UK
Guidelines or they were on reduction treatment with evidence of instability. For these reasons any conclusions as delicate as whether additional methadone could affect cravings over a few hours are based on the most shaky grounds and should be received by the academic community only with great caution.

The authors chose not to develop discussion about the most glaring finding of the study which is that a proportion of English addicts seem to be receiving sub-standard and ineffective treatment in publicly funded clinics. Some would see this as scandalous.

Comment by Andrew Byrne ..