Substitution therapy for amphetamine users

James Shearer, John Sherman, Alex Wodak and Ingrid van Beek
Drug and Alcohol Review (2002) 21, pp. 179•-185
June 2002

publicationThe illicit use of amphetamines continues to be a growing problem in many countries around the world, yet treatment responses remain in need of further development. This is particularly true with regards to pharmacotherapy for amphetamine dependence. In this Harm Reduction Digest four authors who bring together considerable research and clinical experience in this area describe the nature of amphetamine-related problems and consider the role of amphetamine agonists in substitution therapy for amphetamine dependence.

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While illicit amphetamine consumption and associated problems have increased steadily in many countries (including Australia) during the last decade, there has been a relative dearth of research into effective treatments, particularly for severely dependent users who are most vulnerable to the serious adverse consequences of illicit amphetamine use. It is likely that amphetamine-related harms disproportionately accrue to a minority of severely dependent amphetamine users, yet their relatively small numbers and treatment resistance may have resulted in this group being overlooked as a public health policy priority. Several forms of substitution therapies that aim to replace harmful illicit drug use with safer, legal pharmaceutical maintenance have been demonstrated to be safe and effective treatments for drug dependence.

Although there is limited scientific evidence to support safety and efficacy, substitution therapy for amphetamine users has won a degree of clinical acceptance in the United Kingdom. Research into the rationale, safety and efficacy of substitution therapy for amphetamine dependence is at an early stage and is limited by the relatively few trials of generally observational nature, small numbers of patients and lack of controlled findings. However, the evidence to date consistently supports an expansion of efforts to evaluate this intervention. The natural history of amphetamine use and dependence involves a complex interplay of biological, psychological and social factors. Further controlled investigation of substitution therapy in combination with psychosocial interventions for severely dependent amphetamine users is indicated to assess the safety and efficacy (and later the cost-effectiveness) of this intervention in improving outcomes for selected amphetamine users.

Conclusion

At the beginning of the new millennium, amphetamine use is more prevalent and less easily controlled than ever before. Technological, cultural, social and economic change has driven a recent relentless worldwide expansion of amphetamine use. An incomplete understanding of the natural history of problematic amphetamine use and the more obvious short-term harms associated with heroin use may have delayed a comprehensive public health response to widespread amphetamine use. The advent of polydrug use has refocused public health attention towards effective treatments for amphetamine users, particularly dependent and injecting users.

The efficacy of substitution therapy is not known, even though the practice appears to have gained a degree of clinical acceptance at least in the United Kingdom. The literature is not extensive and controlled trials are few. There is a strong and growing case for rigorous evaluation of substitution therapies combined with tailored psychosocial interventions to achieve improved outcomes for amphetamine users.