"23. It might be claimed that this approach [drug injection rooms] is incompatible with the obligations to prevent the abuse of drugs, derived from article 38 of the 1961 Convention and article 20 of the 1971 Convention. It should not be forgotten, however, that the same provisions create an obligation to treat, rehabilitate and reintegrate drug addicts, whose implementation depends largely on the interpretation by the Parties of the terms in question. If, for example, the purpose of treatment is not only to cure a pathology, but also to reduce the suffering associated with it (like in severe-pain management), then reducing IV drug abusers exposure to pathogen agents often associated with their abuse patterns (like those causing HIV-AIDS, or hepatitis B) should perhaps be considered as treatment. In this light, even supplying a drug addict with the drug he depends on could be seen as a sort of rehabilitation and social reintegration, assuming that once his drug requirements are taken care of, he will not need to involve himself in criminal activities to finance his dependence."

Source

"Flexibility of Treaty Provisions as Regards Harm Reduction Approaches," Legal Affairs Section UNDCP (Vienna, Austria: International Narcotics Control Board, September 30, 2002), p. 5.