The most effective and best-studied treatment available in addiction medicine is methadone maintenance treatment (MMT), which leads to a range of benefits for individuals with opioid dependence and society at large.[1] Unfortunately, not all those with opioid dependence benefit from MMT and there is no similar medication available for the treatment of stimulant dependence (particularly crack cocaine or crystal methamphetamine).

The Chronic Addiction Substi­tution Treatment Trials (CAST) are planned as a series of five scientifically rigorous, ethically sound clinical research studies to be conducted in Vancouver to evaluate novel pharmacological strategies for opioid and stimulant dependence. 

As Dr Mela­med and colleagues correctly state, pharmacological treatments are most effective when combined with a full range of psychosocial services such as supportive housing, social supports sufficient to prevent abject poverty, addiction counseling, psychiatric care, and primary medical care, and participants in CAST will receive this full range of services in combin­ation with the study medications. 

Throughout the trial, participants will be able to access these services regardless of whether they continue on the study medications. More importantly, for most of these services, the access will not be limited to the duration of the trials or to those who participate in CAST. For example, over the past year the municipal and provincial governments have announced several new initiatives that will significantly ex­pand access to supportive housing in Vancouver, and while CAST participants will be able to avail of these services, access will not be limited to CAST participants. 

If we insisted, as Dr Melamed and colleagues suggest, that novel medications cannot be evaluated until access to support services is available to all, then we would still be limited to treating hypertension with diuretics while working to ex­pand dietary and exercise programs.

The second misunderstanding within the letter deals with the primary goal of CAST. All the trials are designed with improved health of the participants as the primary outcome. At the same time, it is important to recognize that MMT leads to dra­matic reductions in criminal activity and any other successful substitution treatment is likely to generate similar positive outcomes for society.[2]

Clinical research can be an im­portant vehicle for improving addiction treatment through expanding the range of effective treatment options, highlighting the elements of currently available treatments which can be improved, accessing research-specific funding streams such as the Canadian Institutes of Health Research and facilitating advocacy for those who do not benefit from the present treatment options. We believe it is time those in British Columbia suffering from addiction were offered these benefits.

-David C. Marsh, MD
Co-Chair, Clinical Advisory Committee, CAST

-Michael Krausz, MD
Co-Chair, Clinical Advisory Committee, CAST

References

1. Health Canada. Best practices—Metha­done maintenance treatment. Ottawa: Health Canada, 2002.
2. Sheerin I, Green T, Sellman D, et al. Reduction in crime by drug users on a methadone maintenance therapy programme in New Zealand. NZ Med J 2004;117:U795.