title: Pharmacologic Considerations for Preexposure Prophylaxis in Transgender Women.
abstract: Studies of tenofovir disoproxil fumarate (TDF)-emtricitabine (FTC)-based preexposure prophylaxis (PrEP) have not focused on transgendered women who are at disproportionate risk of HIV acquisition. Concerns exist for drug interactions between cross-sex therapy (estradiol, progestins, and spironolactone) with tenofovir disoproxil fumarate-emtricitabine. This review assessed the experimental and theoretical risk for such drug interactions. It was found that none of these medications are implicated as major perpetrators of drug interactions, and the classes use different metabolic pathways for clearance, suggesting a low likelihood for interactions in either direction. Subanalyses of transgender women in Preexposure Prophylaxis Initiative suggested PrEP efficacy if adherence was high. Nevertheless, several research gaps were identified, particularly the need for controlled interaction studies in transgendered women, including effects on renal clearance, intracellular tenofovir diphosphate and emtricitabine triphosphate in target cells, as well as hormone effects on HIV susceptibility and immunity. PrEP should continue to be offered to transgender women while additional research is planned or pending.
authors.affiliation: *Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado-AMC, Aurora, CO; †Children's Hospital Colorado, University of Colorado-AMC, Aurora, CO; ‡University of Colorado School of Medicine, University of Colorado-AMC, Aurora, CO; and §Division of Infectious Diseases, School of Medicine, University of Colorado-AMC, Aurora, CO.
authors.forename: Peter L
authors.initials: PL
authors.lastname: Anderson
authors.forename: Daniel
authors.initials: D
authors.lastname: Reirden
authors.forename: Jose
authors.initials: J
authors.lastname: Castillo-Mancilla
mesh_terms: D019380:Anti-HIV Agents / Q000494:pharmacology*; D019033:Delivery of Health Care, Integrated; D037001:Directive Counseling; D000068679:Emtricitabine / Q000494:pharmacology*; D005260:Female; D015658:HIV Infections / Q000517:prevention & control* / Q000635:transmission; D054624:Health Status Disparities; D006801:Humans; D008297:Male; D065129:Pre-Exposure Prophylaxis / Q000379:methods; D000068698:Tenofovir / Q000494:pharmacology*; D063106:Transgender Persons; D016903:Drug Monitoring
chemical_list: D019380:Anti-HIV Agents; D000068698:Tenofovir; D000068679:Emtricitabine