Effective use of pre-exposure prophylaxis (PrEP) Among stimulant users with multiple condomless sex partners: a longitudinal study of men who have sex with men in Los Angeles

AIDS Care. 2019 Oct;31(10):1228-1233. doi: 10.1080/09540121.2019.1595523. Epub 2019 Mar 20.


PrEP's potential benefit for men who have sex with men (MSM) who use stimulants may be limited by adherence or prescriber willingness to recommend PrEP due to concerns of non-compliance. Using data from PATH-PrEP, a 48-week study evaluating PrEP for MSM in Los Angeles, we modeled an interaction between stimulant use and condomless sex with multiple partners (CAS-MP) on prevention-effective dried blood spot tenofovir-diphosphate concentrations. At week 4, participants reporting stimulant use and CAS-MP had a decreased odds of prevention-effective adherence compared to non-stimulant use and non-CAS-MP (AOR 0.15, 95% CI 0.04-0.57). From week 4-48, participants reporting stimulant use and CAS-MP had increased odds of prevention-effective adherence (AOR 1.06 per week, 95%CI 1.01-1.12). Participants reporting CAS-MP without stimulant use had no significant change in prevention-effective adherence (AOR 0.99 per week, 95%CI 0.96-1.02). Stimulant use moderated the association of CAS-MP on prevention-effective PrEP adherence over time.

Keywords: MSM; PrEP; adherence; condomless anal sex; stimulant.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenine / analogs & derivatives
  • Adult
  • Anti-Retroviral Agents / administration & dosage*
  • Anti-Retroviral Agents / therapeutic use
  • Central Nervous System Stimulants / therapeutic use*
  • Condoms / statistics & numerical data*
  • HIV Infections / drug therapy
  • HIV Infections / prevention & control*
  • Homosexuality, Male / psychology
  • Homosexuality, Male / statistics & numerical data*
  • Humans
  • Longitudinal Studies
  • Los Angeles
  • Male
  • Medication Adherence*
  • Organophosphates
  • Pre-Exposure Prophylaxis / methods*
  • Sexual Partners*
  • Tenofovir / administration & dosage*
  • Tenofovir / therapeutic use
  • Unsafe Sex


  • Anti-Retroviral Agents
  • Central Nervous System Stimulants
  • Organophosphates
  • tenofovir diphosphate
  • Tenofovir
  • Adenine