Delivery of TDF/FTC for Pre-exposure Prophylaxis to Prevent HIV-1 Acquisition in Young Adult Men Who Have Sex With Men and Transgender Women of Color Using a Urine Adherence Assay.

BACKGROUND: Pre-exposure prophylaxis (PrEP) for HIV prevention with daily tenofovir and emtricitabine is effective when taken consistently. Currently, there is no objective way to monitor PrEP adherence. Urine has been shown to be highly correlated with plasma tenofovir levels, with urine tenofovir levels >1000 ng/mL demonstrating recent (1-2 days) adherence to PrEP. SETTING: This study was conducted at an urban community health center in Philadelphia, Pennsylvania. METHODS: PrEP was administered to 50 young men who have sex with men and transgender women of color using weekly, biweekly, and/or monthly dispensation schedules. Primary objectives were retention at 48 weeks (in care at week 48 and completing ≥50% of medication pickups) and adherence assessed by urine tenofovir levels. Risk behaviors and sexually transmitted infection diagnoses were also collected. RESULTS: Seventy percent of participants were retained in care at 48 weeks. The proportion of subjects with urine tenofovir consistent with recent adherence was 80, 74.4, 82.4, 82.4, and 69.7% at weeks 4, 12, 24, 36, and 48, respectively. Sixty-one sexually transmitted infections were diagnosed over 231 screenings throughout 48 weeks, with no significant change between the first and second 24-week periods (P = 0.43; 0 seroconversions). At week 48, more than half of subjects reported an increase or no change in condom use, an increase in their ability to discuss HIV with partners, and no change in number of sexual partners from baseline. CONCLUSIONS: These data demonstrate PrEP can be successfully delivered to a high-risk population with high program retention and medication adherence measured by urine tenofovir levels.

A case study of chewed Truvada® for PrEP maintaining protective drug levels as measured by a novel urine tenofovir assay.

Emtricitabine/tenofovir disoproxil fumarate (FTC/TDF; Truvada®) given as pre-exposure prophylaxis (PrEP) successfully blocks HIV when taken once daily prior to potential HIV exposure. A 22-year-old male reported difficulty swallowing FTC/TDF for PrEP and subsequently began chewing the FTC/TDF tablets. Monthly urine samples assessed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) indicated tenofovir levels >1,000 ng/ml, indicative of protection from HIV acquisition, over a 48-week period. Data from observational studies of HIV-positive patients details the successful treatment of HIV using crushed FTC/TDF delivered via feeding and gastronomy tubes while small, randomized trials of healthy volunteers demonstrate bioequivalence between whole and crushed FTC/TDF.