Concomitant use of cocaine and HIV pre-exposure prophylaxis (PrEP) raises important clinical questions around adherence, retention in care, and renal toxicity.
We assessed the associations of confirmed cocaine use with PrEP adherence (both ascertained through objective measures), care engagement, and renal function in the iPrEx open-label extension. Cocaine use was measured in scalp hair samples and categorized as light (500–3000 pg/mg) and moderate to heavy (>3000 pg/mg). PrEP adherence in the first 3 months was measured through plasma tenofovir concentrations. Disengagement from PrEP care was defined as a gap in follow-up greater than 4 months. Serum creatinine was assessed at baseline and quarterly visits.
Of the 400 participants included in this analysis, 90% were men who have sex with men, 10% transgender women, 74% Hispanic/Latino; 21% tested positive for cocaine use in the last 3 months. In adjusted analysis, light cocaine use [adjusted odds ratio 2.10 (95% confidence interval: 1.07 to 4.14)] and moderate to heavy use [adjusted odds ratio 2.32 (1.08 to 5.00)] were associated with greater odds of having plasma tenofovir concentrations below the level of quantitation. Participants with moderate to heavy use had a nearly 3-fold higher rate of disengagement from PrEP care compared with nonusers (adjusted hazard ratio 2.90 [1.48 to 5.66]). We found no statistically or clinically significant differences in creatinine clearance and serum creatinine between participants who tested positive for cocaine and those who did not.
Cocaine use decreases PrEP adherence and care engagement. Comprehensive approaches are needed to reduce cocaine use and enhance engagement along the PrEP care continuum.
aDepartment of Psychiatry, Weill Institute for Neurosciences, University of California, San Francisco, CA;
bDivision of Research, Kaiser Permanente Northern California, Oakland, CA;
cDepartment of Biostatistics and Epidemiology, University of California, San Francisco, CA;
dDepartment of Health Services, University of Washington, Seattle, WA;
eDepartment of Medicine, University of California, San Francisco, CA;
fInvestigaciones Medicas en Salud, Lima, Peru; and
gDepartment of Public Health Sciences, University of Miami, FL.
Correspondence to: Jose Carlo Hojilla, RN, PhD, Department of Psychiatry, Weill Institute for Neurosciences, University of California, 401 Parnassus Avenue, San Francisco, CA 94143 (e-mail: email@example.com).
Supported by the National Institute on Drug Abuse (NIDA R36 DA041906 and T32 DA007250). iPrEx OLE was funded by the National Institute of Allergy and Infectious Diseases (NIAID U01 AI064002 and R01 AI118575). Hair collection was funded by NIAID R01 AI098472. Gilead Sciences donated tenofovir disoproxil fumarate and emtricitabine to the parent study but provided no other financial support and had no role in data interpretation or manuscript development.
Presented in part at the HIV Research for Prevention Conference; October 2018; Madrid, Spain.
D.V.G. has received fees from Gilead Sciences. R.M.G. has received research funding from ViiV Healthcare. The remaining authors have no conflicts of interest to disclose.
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Received September 26, 2018
Accepted December 21, 2018