title: Pre-exposure Prophylaxis Adherence Measured by Plasma Drug Level in MTN-001: Comparison Between Vaginal Gel and Oral Tablets in Two Geographic Regions.
abstract: Despite strong evidence that daily oral pre-exposure prophylaxis (PrEP) reduces HIV risk, effectiveness across studies has varied. Inconsistent adherence constitutes one explanation. Efforts to examine adherence are limited when they rely on self-reported measures. We examined recent adherence as measured by plasma tenofovir (TFV) concentration in participants of MTN-001, a phase 2 cross-over trial comparing oral tablet and vaginal gel formulations of TFV among 144 HIV-uninfected women at sites in the United States (U.S.) and sub-Saharan Africa (SSA). Adherence to daily product use was higher in the U.S. than in the SSA sites. Within region, however, adherence was similar between products. In the U.S., gel adherence was higher among married women, and lower among women using male condoms and injectable contraceptives. At the SSA sites, gel adherence was lower for younger women. Inconsistent adherence points to challenges in use of daily PrEP, even during a trial of short duration.
authors.affiliation: Women's Global Health Imperative, RTI International, 351 California Street, Suite 500, San Francisco, CA, 94104, USA. aminnis@rti.org.|School of Public Health, University of California, Berkeley, USA. aminnis@rti.org.
authors.forename: Alexandra M
authors.initials: AM
authors.lastname: Minnis
authors.affiliation: Women's Global Health Imperative, RTI International, 351 California Street, Suite 500, San Francisco, CA, 94104, USA.|Center for AIDS Prevention Studies (CAPS) Department of Medicine, University of California San Francisco, San Francisco, CA, USA.
authors.forename: Ariane
authors.initials: A
authors.lastname: van der Straten
authors.affiliation: Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Parichat
authors.initials: P
authors.lastname: Salee
authors.affiliation: School of Medicine, The Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Craig W
authors.initials: CW
authors.lastname: Hendrix
mesh_terms: D000284:Administration, Oral; D000287:Administration, Topical; D000293:Adolescent; D000328:Adult; D017954:Africa South of the Sahara; D019380:Anti-HIV Agents / Q000008:administration & dosage*; D018592:Cross-Over Studies; D005260:Female; D015658:HIV Infections / Q000517:prevention & control*; D006801:Humans; D055118:Medication Adherence; D008875:Middle Aged; D010342:Patient Acceptance of Health Care / Q000523:psychology / Q000706:statistics & numerical data*; D057240:Patient Preference / Q000523:psychology / Q000706:statistics & numerical data*; D065129:Pre-Exposure Prophylaxis; D013607:Tablets / Q000008:administration & dosage*; D000068698:Tenofovir / Q000008:administration & dosage / Q000097:blood*; D014481:United States; D014622:Vaginal Creams, Foams, and Jellies / Q000008:administration & dosage*; D055815:Young Adult
chemical_list: D019380:Anti-HIV Agents; D013607:Tablets; D014622:Vaginal Creams, Foams, and Jellies; D000068698:Tenofovir
keywords: Biomarker; HIV prevention; Medication adherence; Pre-exposure prophylaxis