"In particular, Russian law forbids substitution therapy for opioid dependence with methadone or buprenorphine. Naltrexone is the only specific pharmacotherapy that is currently approved for use in the Russian Federation and is available as an oral tablet in extended-release formulations."

Source

Krupitsky, Evgeny, Zvartau, Edwin, and Woody, George, "Use of Naltrexone to Treat Opioid Addiction in a Country in Which Methadone and Buprenorphine Are Not Available," Current Psychiatry Reports, 2010 October; 12(5): 448–453. doi:10.1007/s11920-010-0135-5.
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