Decreasing intravenous cocaine use in opiate users treated with prescribed heroin

Providing maintenance treatment for heroin users who also use cocaine presents special problems. Poly-drug use is prevalent among clients in the Swiss Program for the Medical Prescription of Heroin (1994-1996).

A formative evaluation examines whether cocaine use was associated with a higher drop-out rate from treatment, and how cocaine use changed among those who remained in treatment. Frequency of cocaine use before and during treatment was measured by self-report every six months and by urinalysis every two months.

There was no significant difference between the drop-out rates for cocaine users vs. non-users (n = 995). A significant reduction in cocaine use over an 18-month period from 84 to 48% was found for a sample of clients (n = 266). Overall retention in programme was high and also the prevalence of factors associated with cocaine use such as criminality, prostitution, and contact with drug scene decreased.

The results suggest that prescribed heroin maintenance provides a treatment context that may help reduce consumption of other illicit drugs such as cocaine.