CAST REPLIES

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 Substi-tution 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 Mela-med 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
combin-ation 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 ex-pand 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 ex-pand 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 dra-matic 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 im-portant 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-Metha-done 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.