title: Emergence of methadone as a street drug in St. Petersburg, Russia.
abstract: BACKGROUND
  The syndemic of opioid addiction, HIV, hepatitis, tuberculosis, imprisonment, and overdose in Russia has been worsened by the illegality of opioid substitution therapy. As part of on-going serial studies, we sought to explore the influence of opioid availability on aspects of the syndemic as it has affected the city of St. Petersburg.
  
  
  METHODS
  We employed a sequential approach in which quantitative data collection and statistical analysis were followed by a qualitative phase. Quantitative data were obtained in 2013-2014 from a respondent-driven sample (RDS) of people who inject drugs (PWID). Individuals recruited by RDS were tested for antibodies to HIV and interviewed about drug use and injection practices, sociodemographics, health status, and access to medical care. Subsequently, we collected in-depth qualitative data on methadone use, knowledge, and market availability from PWID recruited at nine different locations within St. Petersburg.
  
  
  RESULTS
  Analysis of interview data from the sample revealed the percentage of PWID injecting methadone in the 30 days prior to interview increased from 3.6% in 2010 to 53.3% in 2012-2013. Injection of only methadone, as compared to injecting only heroin or both drugs, was associated with less frequent injection and reduced HIV-related injected risk, especially a lower rate of injecting with a previously used syringe. In-depth questioning of methadone injectors corroborated the finding from serial quantitative surveys of PWID that methadone's black market availability is a recent phenomenon. Spatial analysis revealed widespread methadone availability but no concentration in any specific districts of the city.
  
  
  CONCLUSIONS
  Despite the prohibition of substitution therapy and demonization of methadone, the drug has emerged to rival heroin as the most commonly available opioid in St. Petersburg. Ironically, its use is associated with reduced injection-related HIV risk even when its use is illegal.
authors.affiliation: Center for Interdisciplinary Research on AIDS and Department of the Epidemiology of Microbial Disease, Yale University School of Public Health, New Haven, CT, USA. Electronic address: robert.heimer@yale.edu.
authors.forename: Robert
authors.initials: R
authors.lastname: Heimer
authors.affiliation: NGOStellit, St. Petersburg, Russia.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Lyubimova
authors.affiliation: Center for Interdisciplinary Research on AIDS and Department of the Epidemiology of Microbial Disease, Yale University School of Public Health, New Haven, CT, USA.
authors.forename: Russell
authors.initials: R
authors.lastname: Barbour
authors.affiliation: NGOStellit, St. Petersburg, Russia.
authors.forename: Olga S
authors.initials: OS
authors.lastname: Levina
mesh_terms: D000328:Adult; D003625:Data Collection; D005260:Female; D006556:Heroin Dependence / Q000453:epidemiology*; D006801:Humans; D013287:Illicit Drugs; D008297:Male; D008691:Methadone / Q000008:administration & dosage* / Q000009:adverse effects; D058850:Opiate Substitution Treatment; D009293:Opioid-Related Disorders / Q000453:epidemiology*; D012426:Russia / Q000453:epidemiology; D015819:Substance Abuse, Intravenous / Q000453:epidemiology*
chemical_list: D013287:Illicit Drugs; D008691:Methadone
keywords: Black markets; HIV risk; Heroin; Methadone; Russia