Montgomery, Madeline C.Oldenburg, Catherine E.Nunn, Amy S.Mena, LeandroAnderson, PeterLiegler, TeriMayer, KennethPatel, RupaAlmonte, AlexiChan, Philip A.2016-08-092016Montgomery, Madeline C., Catherine E. Oldenburg, Amy S. Nunn, Leandro Mena, Peter Anderson, Teri Liegler, Kenneth H. Mayer, Rupa Patel, Alexi Almonte, and Philip A. Chan. 2016. “Adherence to Pre-Exposure Prophylaxis for HIV Prevention in a Clinical Setting.” PLoS ONE 11 (6): e0157742. doi:10.1371/journal.pone.0157742. http://dx.doi.org/10.1371/journal.pone.0157742.1932-6203http://nrs.harvard.edu/urn-3:HUL.InstRepos:27822403Background: The HIV epidemic in the United States (US) disproportionately affects gay, bisexual, and other men who have sex with men (MSM). Pre-exposure prophylaxis (PrEP) using co-formulated tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC) has demonstrated high efficacy in reducing HIV incidence among MSM. However, low adherence was reported in major efficacy trials and may present a substantial barrier to successful PrEP implementation. Rates of adherence to PrEP in “real-world” clinical settings in the US remain largely unknown. Methods: We reviewed demographic and clinical data for the first 50 patients to enroll in a clinical PrEP program in Providence, Rhode Island. We analyzed self-reported drug adherence as well as drug concentrations in dried blood spots (DBS) from patients who attended either a three- or six-month follow-up appointment. We further assessed drug concentrations and the resistance profile of a single patient who seroconverted while taking PrEP. Results: Of the first 50 patients to be prescribed PrEP, 62% attended a follow-up appointment at three months and 38% at six months. Of those who attended an appointment at either time point (70%, n = 35), 92% and 95% reported taking ±4 doses/week at three and six months, respectively. Drug concentrations were performed on a random sample of 20 of the 35 patients who attended a follow-up appointment. TDF levels consistent with ±4 doses/week were found in 90% of these patients. There was a significant correlation between self-reported adherence and drug concentrations (r = 0.49, p = 0.02). One patient who had been prescribed PrEP seroconverted at his three-month follow-up visit. The patient’s drug concentrations were consistent with daily dosing. Population sequencing and ultrasensitive allele-specific PCR detected the M184V mutation, but no other TDF- or FTC-associated mutations, including those present as minor variants. Conclusion: In this clinical PrEP program, adherence was high, and self-reported drug adherence accurately reflected drug concentrations as measured by DBS.en-USBiology and Life SciencesImmunologyVaccination and ImmunizationProphylaxisPre-Exposure ProphylaxisMedicine and Health SciencesPublic and Occupational HealthPreventive MedicinePharmacologyDrug AdherenceMicrobiologyMicrobial ControlAntimicrobial ResistanceMedicine and health sciencesPublic and occupational healthPreventive medicineHIV preventionHealth CarePatientsPeople and PlacesPopulation GroupingsSexual PreferencesMen WHO Have Sex with MenMedical MicrobiologyMicrobial PathogensViral PathogensImmunodeficiency VirusesHIVPathology and Laboratory MedicinePathogensOrganismsVirusesBiology and life sciencesRNA virusesRetrovirusesLentivirusInfectious diseasesViral diseasesHIV infectionsJournal Article2016-08-0910.1371/journal.pone.0157742