International Drug Conventions and Heroin-Assisted Treatment
"Many countries believe (erroneously) that the international drug conventions prohibit the use of heroin in medical treatment. Furthermore, the International Narcotics Control Board (INCB) has exerted great pressure on countries to cease prescribing heroin for any medical purpose. Nevertheless, a few countries, including the UK, Belgium, the Netherlands, Iceland, Malta, Canada and Switzerland, continue to use heroin (diamorphine) for general medical purposes, mostly in hospital settings (usually for severe pain relief). Until recently, however, Britain was the only country that allowed doctors to prescribe heroin for the treatment of drug dependence."
Stimson, Gerry V., and Nicky Metrebian, Centre for Research on Drugs and Health Behavior, "Prescribing Heroin: What is the Evidence?" (London, England: Rowntree Foundation, 2003), p. 4.