title: Feasibility of a breath test for monitoring adherence to vaginal administration of antiretroviral microbicide gels.
abstract: Adherence to microbicide gel use is critical to optimizing effectiveness in preventing human immunodeficiency virus transmission. The authors hypothesized that ester taggants added to vaginal gels would generate exhaled alcohol and ketone metabolites and provide a "breath test" for vaginal gel use. This 2-arm (vaginal and dermal), randomized, participant-blinded, pilot study tested this hypothesis. On 8 visits, healthy women (n = 8) received intravaginal taggant (2-butyl acetate, 2-pentyl acetate, isopropyl butyrate, or 2-pentyl butyrate; 30 mg) formulated in hydroxyethylcellulose or tenofovir placebo gel. A second group (n = 4) of women received the same formulations administered dermally on the forearm to determine if skin administration might confound the system. Breath samples were collected using bags before and after taggant administration for 1 hour. Samples were measured using a miniature gas chromatograph and/or gas chromatography-mass spectroscopy for ester taggant, alcohol, and ketone concentrations. After vaginal administration, 2-butyl acetate, 2-pentyl acetate, and metabolites were observed in breath, whereas isopropyl butyrate, 2-pentyl butyrate, and metabolites were not. Some women reported self-resolving, mild burning (24/64 visits) with vaginal administration or a "bubblegum" taste (7/64 visits). No taggants or metabolites were detected following dermal application. A "breath test" for adherence to antiretroviral vaginal gel application appears physiologically and technically feasible.
authors: Department of Anesthesiology, University of Florida College of Medicine, Gainesville, FL, USA.
authors: Timothy E
authors: TE
authors: Morey
authors: Scott
authors: S
authors: Wasdo
authors: Judith
authors: J
authors: Wishin
authors: Brian
authors: B
authors: Quinn
authors: Ariane
authors: A
authors: van der Straten
authors: Matthew
authors: M
authors: Booth
authors: Daniel
authors: D
authors: Gonzalez
authors: Hartmut
authors: H
authors: Derendorf
authors: Richard J
authors: RJ
authors: Melker
authors: Donn M
authors: DM
authors: Dennis
mesh_terms: D000085:Acetates / Q000008:administration & dosage* / Q000493:pharmacokinetics; D000225:Adenine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D000279:Administration, Cutaneous; D000282:Administration, Intravaginal; D000293:Adolescent; D000328:Adult; D019380:Anti-HIV Agents / Q000008:administration & dosage*; D001944:Breath Tests; D016903:Drug Monitoring / Q000379:methods*; D005260:Female; D006801:Humans; D008875:Middle Aged; D063065:Organophosphonates / Q000008:administration & dosage*; D010349:Patient Compliance; D000068698:Tenofovir; D014622:Vaginal Creams, Foams, and Jellies / Q000008:administration & dosage; D055815:Young Adult
chemical_list: D000085:Acetates; D019380:Anti-HIV Agents; D063065:Organophosphonates; D014622:Vaginal Creams, Foams, and Jellies; D000068698:Tenofovir; D000225:Adenine