title: Viagra, methamphetamine, and HIV risk: results from a probability sample of MSM, San Francisco.
abstract: OBJECTIVE
  To determine the prevalence and factors of Viagra use in combination with crystal methamphetamine and its association with HIV risk behavior in a probability sample of men who have sex with men (MSM).
  
  
  METHODS
  A cross-sectional, random-digit dial telephone survey of MSM in San Francisco conducted between June 2002 and January 2003.
  
  
  RESULTS
  Of the 1976 MSM, 13.5% used Viagra alone, 7.1% used methamphetamine without Viagra, 9.6% used Viagra with a mood-altering substance (excluding methamphetamine), and 5.1% used Viagra with methamphetamine. Of the MSM using Viagra with methamphetamine, 57% were HIV-infected and 24% of these men reported serodiscordant unprotected insertive intercourse. Viagra used with methamphetamine was independently associated with a higher risk of serodiscordant unprotected insertive intercourse, serodiscordant unprotected receptive intercourse, and a recent diagnosis of a sexually transmitted disease.
  
  
  CONCLUSIONS
  MSM who use Viagra with crystal methamphetamine have high prevalence rates of HIV and engage in HIV risk behaviors.
authors.affiliation: San Francisco Department of Public Health, San Francisco, California, USA. hilary.spindler@gmail.com
authors.forename: Hilary H
authors.initials: HH
authors.lastname: Spindler
authors.forename: Susan
authors.initials: S
authors.lastname: Scheer
authors.forename: Sanny Y
authors.initials: SY
authors.lastname: Chen
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Klausner
authors.forename: Mitchell H
authors.initials: MH
authors.lastname: Katz
authors.forename: Linda A
authors.initials: LA
authors.lastname: Valleroy
authors.forename: Sandra K
authors.initials: SK
authors.lastname: Schwarcz
mesh_terms: D000328:Adult; D015658:HIV Infections / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control*; D018451:Homosexuality, Male; D006801:Humans; D008297:Male; D008694:Methamphetamine; D008875:Middle Aged; D010879:Piperazines; D015995:Prevalence; D011687:Purines; D012307:Risk Factors; D012309:Risk-Taking; D012494:Sampling Studies; D012495:San Francisco / Q000453:epidemiology; D000068677:Sildenafil Citrate; D013450:Sulfones
chemical_list: D010879:Piperazines; D011687:Purines; D013450:Sulfones; D008694:Methamphetamine; D000068677:Sildenafil Citrate