Methadone

Methadone is prescribed to heroin addicts as a substitute for heroin. Prescribing methadone as a heroin substitute was the first outpatient treatment that heroin addicts would attend reliably. Since the early studies hundreds more have shown that maintenance treatment with methadone reduces (though it does not eliminate) the use of opiates and criminal behaviour.

Methadone treatment reduces illicit use of herion and criminal actions and lowers the risk of HIV infection mortality and improves social rehabilitation.

The same enthusiasm for methadone is apparent in the United States, where the Institute of Medicine recently published a review that endorsed the effectiveness of this type of maintenance treatment3--a verdict in line with other reviews in the past 10 years.4 5 A further report in 1995 by Robert Newman showed that methadone treatment has gained a solid foothold in Germany.6 All the evidence points, then, to wide acceptance of methadone maintenance treatment.7 Patients who have been legally coerced into methadone treatment show the same changes in behaviour as those who volunteered without legal persuasion.8 Furthermore, people who continue to be treated with methadone--whether in an abstinence-oriented clinic or in one that tolerates continued illicit use of drugs--show a progressive reduction in the rate of convictions.9 The benefits on the rate of transmission of HIV infections are also robust: several studies have shown that seroconversion may be reduced in those receiving methadone maintenance to as little as one sixth of the rate in untreated opiate addicts,10 and the treatment programmes also serve as a platform for delivering medical services to drug users infected with HIV. Recently there has been a dramatic growth in the provision of methadone in Europe.11 In this issue of the BMJ, Sheridan et al (p 272) report that the number of pharmacies prescribing opiates in England and Wales more than doubled between 1988 and 1995,12 and an accompanying article by Strang et al (p 270) points out that methadone is the most commonly prescribed opiate.13

Nevertheless, methadone treatment is not a panacea, and it has always been controversial. Giving an addictive substance to an addict raises objections from many sources. When methadone is prescribed or supplied directly it may create iatrogenic addiction by being sold for illicit use. About a tenth of the prescriptions reported by Strang et al were for tablets, which can be ground up and injected, and a tenth for injectable ampoules.13 It has been suggested that countries such as Britain, where use of methadone is less closely regulated, have more scope for diversion of methadone to people not being prescribed the drug.14 A third paper in this issue supports this suggestion. Cairns et al (p 264) report that deaths in Manchester involving methadone increased from 10 in 1985-90 to 80 in 1990-4.15 Only two fifths of those deaths occured in people who were being prescribed methadone. Another drawback is that methadone is not a treatment for abuse of cocaine. One recent study of 229 patients taking methadone found that their abuse of opiates had decreased with time in treatment, but their use of cocaine continued and did not seem to be related to the length of time in the programme.16

A dose of methadone has no magical effect on the personality, job skills, or support systems of a drug abuser. Programmes that offer little in the way of counselling, employment support, or training in the prevention of relapse are unlikely to make much change in social functioning. Perhaps for this reason a recent study of opiate users in Amsterdam (where methadone is available as a "low threshold" treatment with relatively little ongoing counselling) concluded that methadone in itself had no effect on the extent of drug users' criminal behaviour.17 Methadone programmes attract a highly disadvantaged population, and rehabilitation is a long, difficult process for them, fraught with the danger of relapse.

Methadone is not a miracle cure; it should not be oversold and then be criticised for failing to live up to unrealistic expectations. As an outpatient treatment of opiate abuse methadone is extremely effective. After 30 years our opinion of the treatment may need some modification, but not much. Newman's article about the growth of methadone treatment in Germany6 seemed to strike the right balance: "What is needed today is not further discussion, but a firm commitment to make treatment available on request to every addict willing to accept it. There is no justification for settling for less."6

Supported in part by Grants R18DA06097, R01DA08753, and P5009235 from the National Institute on Drug Abuse.

Adjunct professor of psychiatry Substance Abuse Services, University of California, San Francisco, CA 94110, USA

Resources

• Carnwath, T., Gabbay, M, Perry, M, Benbow, E. W, Roberts, I. S D, Cairns, A. (1997). Fatal methadone overdose. BMJ 315: 55-55
• Robertson, J R, Macleod, J (1996). Methadone treatment. BMJ 313: 1480c-1481
• Merrill, J., Garvey, T., Rosson, C. (1996). Methadone concentrations taken as indicating deaths due to overdose need to be reviewed. BMJ 313: 1481a-1481