Trial reportPloS one2014
Strong relationship between oral dose and tenofovir hair levels in a randomized trial: hair as a potential adherence measure for pre-exposure prophylaxis (PrEP).
Trial report in PloS one, 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to 5 registered trials, which are not on this map. Cited by 117 papers, 2 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
A Phase 1 Pharmacokinetic Study of Varying Dosing Patterns on Tenofovir Concentrations in Hair
URBAN ARCH (3/5) Uganda Cohort TB Preventive Therapy for HIV-infected Alcohol Users in Uganda: an Evaluation of Safety Tolerability and Adherence
A Comparative Effectiveness Demonstration Project for Linkage and Retention in PrEP Care for Men Who Have Sex With Men (PCA)
Therapeutic Drug Monitoring of Corticosteroids/β2-agonists in Hair in Asthmatic Patients: an Open-label Feasibility Study
Integrating PrEP Into Family Planning Services at Title X Clinics in the Southeastern US
Who cites it
117 citing papers in PubMed, 2 syntheses or guidelines pooled it.
- Adherence and HIV Protection Thresholds for Emtricitabine and Tenofovir Disoproxil Fumarate Preexposure Prophylaxis among Cisgender Women: A Systematic Review.Current HIV/AIDS reports · 2024Pooled it
- Antiretroviral Concentration in Hair as a Measure for Antiretroviral Medication Adherence: A Systematic Review of Global Literature.AIDS and behavior · 2020Pooled it
- Point-of-Care Urine Tenofovir Drug-Level Feedback Counseling Improves Long-Term Pre-exposure Prophylaxis Adherence for US Men Who Have Sex With Men in Pilot RCT.Clinical infectious diseases : an official publication of the Infectious Diseases Society of America · 2026Trial
- Weekly Text Messages to Support Adherence to Oral Pre-Exposure Prophylaxis (PrEP) Among Gay, Bisexual, and Other Cisgender Men Who Have Sex With Men (MSM) and Transgender Women: Pilot Randomized Controlled Trial Nested in PrEP Brasil Study.Journal of medical Internet research · 2025Trial
- Drug Concentrations in Hair and Dried Blood Spots as Preexposure Prophylaxis Adherence Metrics During Pregnancy and Postpartum.The Journal of infectious diseases · 2024Trial
- Impact of a point-of-care urine tenofovir assay on adherence to HIV pre-exposure prophylaxis among women in Kenya: a randomised pilot trial.The lancet. HIV · 2024Trial
- PrEPare for Work: A Pilot Randomized Controlled Trial of an Intervention to Optimize HIV PrEP Outcomes Among Male Sex Workers.AIDS and behavior · 2023Trial
- Safety and pharmacokinetics of islatravir subdermal implant for HIV-1 pre-exposure prophylaxis: a randomized, placebo-controlled phase 1 trial.Nature medicine · 2021Trial
- TransPrEP: Results from the Pilot Study of a Social Network-Based Intervention to Support PrEP Adherence Among Transgender Women in Lima, Peru.AIDS and behavior · 2021Trial
- Urine Tenofovir Concentrations Correlate With Plasma and Relate to Tenofovir Disoproxil Fumarate Adherence: A Randomized, Directly Observed Pharmacokinetic Trial (TARGET Study).Clinical infectious diseases : an official publication of the Infectious Diseases Society of America · 2020Trial
- Short- and Long-Term Pharmacologic Measures of HIV Pre-exposure Prophylaxis Use Among High-Risk Men Who Have Sex With Men in HPTN 067/ADAPT.Journal of acquired immune deficiency syndromes (1999) · 2019Trial
- Trial
- Pre-exposure Prophylaxis With Tenofovir Disoproxil Fumarate/Emtricitabine and Kidney Tubular Dysfunction in HIV-Uninfected Individuals.Journal of acquired immune deficiency syndromes (1999) · 2018Trial
- Intracellular Tenofovir-Diphosphate and Emtricitabine-Triphosphate in Dried Blood Spots following Directly Observed Therapy.Antimicrobial agents and chemotherapy · 2018Trial
- Comparing pharmacologic measures of tenofovir exposure in a U.S. pre-exposure prophylaxis randomized trial.PloS one · 2018Trial
- Trial
- Divergent adherence estimates with pharmacokinetic and behavioural measures in the MTN-003 (VOICE) study.Journal of the International AIDS Society · 2016Trial
- Behavioral intervention improves treatment outcomes among HIV-infected individuals who have delayed, declined, or discontinued antiretroviral therapy: a randomized controlled trial of a novel intervention.AIDS and behavior · 2015Trial
- Comparing the novel method of assessing PrEP adherence/exposure using hair samples to other pharmacologic and traditional measures.Journal of acquired immune deficiency syndromes (1999) · 2015Trial
- Patterns and correlates of PrEP drug detection among MSM and transgender women in the Global iPrEx Study.Journal of acquired immune deficiency syndromes (1999) · 2014Trial
57 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
12 authors.
Funding
Abstract
backgroundPre-exposure prophylaxis (PrEP) trials using tenofovir-based regimens have demonstrated that high levels of adherence are required to evaluate efficacy; the incorporation of objective biomarkers of adherence in trial design has been essential to interpretation, given the inaccuracy of self-report. Antiretroviral measurements in scalp hair have been useful as a marker of long-term exposure in the HIV treatment setting, and hair samples are relatively easy and inexpensive to collect, transport, and store for analysis. To evaluate the relationship between dose and tenofovir concentrations in hair, we examined the dose proportionality of tenofovir in hair in healthy, HIV-uninfected adults.
methodsA phase I, crossover pharmacokinetic study was performed in 24 HIV-negative adults receiving directly-observed oral tenofovir tablets administered 2, 4, and 7 doses/week for 6 weeks, with a ≥3-week break between periods. Small samples of hair were collected after each six-week period and analyzed for tenofovir concentrations. Geometric-mean-ratios compared levels between each pair of dosing conditions. Intensive plasma pharmacokinetic studies were performed during the daily-dosing period to calculate areas-under-the-time-concentration curves (AUCs).
resultsOver 90% of doses were observed per protocol. Median tenofovir concentrations in hair increased monotonically with dose. A log-linear relationship was seen between dose and hair levels, with an estimated 76% (95% CI 60-93%) increase in hair level per 2-fold dose increase. Tenofovir plasma AUCs modestly predicted drug concentrations in hair.
conclusionsThis study found a strong linear relationship between frequency of dosing and tenofovir levels in scalp hair. The analysis of quantitative drug levels in hair has the potential to improve adherence measurement in the PrEP field and may be helpful in determining exposure thresholds for protection and explaining failures in PrEP trials. Hair measures for adherence monitoring may also facilitate adherence measurement in real-world settings and merit further investigation in upcoming PrEP implementation studies and programs.
trial registrationClinicalTrials.gov NCT00903084.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.