1. A Cross-Biomeasure Study to Optimize Antiretroviral Adherence Estimation.
- Author
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Devanathan AS, Poliseno AJ, White NR, Schauer AP, Sykes C, Weideman AMK, Kilpatrick KW, Hudgens MG, Gay CL, Rosen EP, Dumond JB, Kashuba ADM, and Cottrell ML
- Subjects
- Humans, Male, Adult, Female, Middle Aged, Tandem Mass Spectrometry, Organophosphates pharmacokinetics, Organophosphates blood, Young Adult, Dried Blood Spot Testing methods, Chromatography, Liquid, Adenine analogs & derivatives, Adenine pharmacokinetics, Adenine therapeutic use, Leukocytes, Mononuclear metabolism, Leukocytes, Mononuclear chemistry, HIV Infections drug therapy, Medication Adherence, Anti-HIV Agents pharmacokinetics, Anti-HIV Agents therapeutic use, Anti-HIV Agents blood, Emtricitabine pharmacokinetics, Emtricitabine therapeutic use, Tenofovir pharmacokinetics, Tenofovir therapeutic use, Tenofovir blood
- Abstract
Background: Incomplete adherence to daily tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) reduces effectiveness. Adherence biomeasures (ie, drug concentrations in biological specimen) are more accurate than self-report. TDF/FTC's intracellular active metabolites (tenofovir-diphosphate; TFVdp and FTC-triphosphate; FTCtp) can be quantified in different types of blood samples to estimate adherence. To optimize adherence estimation, we investigated approaches to measure TFVdp and FTCtp in 4 blood matrices., Methods: Twelve HIV-negative, healthy volunteers were enrolled in a single-center, open-label, 3-phase, directly observed therapy study. LC-MS/MS methods quantified TFVdp/FTCtp in dried blood spots, volumetrically accurate microsampling, upper layer packed cells, and peripheral blood mononuclear cells (PBMCs). Noncompartmental analysis estimated half-lives and accumulation ratios. Correlations characterized relationships between clinical variables and exposure. Regression models were fit to determine concentrations associated with <4 and ≥4 doses/week; correct classification percentages were determined., Results: Terminal half-life estimates of 3-4 vs 15-22 days distinguished between moderate-term (FTCtp in all samples; TFVdp in PBMCs) versus long-term (TFVdp in red blood cell-containing matrices) measures. Model-derived thresholds accurately categorized <4 and ≥4 doses/week when including both metabolites for 14- and 28-day dosing periods (81%-91% and 82%-85%, respectively). Within each classification and regression trees analyses containing both moderate- and long-term measures, dried blood spots exhibited highest accuracy to predict stable (74%-94%) and changing (42%-47%) adherence patterns., Conclusions: We demonstrate higher accuracy of moderate-term biomeasures to classify adherence over a 14-day period compared with long-term biomeasures to classify adherence over a 28-day period. Combined moderate- and long-term biomeasures predicted stable and changing adherence patterns, with dried blood spots exhibiting highest accuracy., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)
- Published
- 2025
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