Trial reportAntimicrobial agents and chemotherapy2018
Intracellular Tenofovir-Diphosphate and Emtricitabine-Triphosphate in Dried Blood Spots following Directly Observed Therapy.
Trial report in Antimicrobial agents and chemotherapy, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT02022657 (PrEP Adherence Monitoring Using Dried Blood Spots), which is not on this map. Cited by 212 papers, 4 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.
PrEP Adherence Monitoring Using Dried Blood Spots
Who cites it
212 citing papers in PubMed, 4 syntheses or guidelines pooled it, 275 citations in OpenAlex.
- Performance of Adherence Measures for Oral, Tenofovir-Based HIV Pre-Exposure Prophylaxis: A Systematic Review.AIDS and behavior · 2025Pooled 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
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- A systematic review of adherence to oral pre-exposure prophylaxis for HIV - how can we improve uptake and adherence?BMC infectious diseases · 2018Pooled it
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- Evaluating adherence in an active-controlled HIV pre-exposure prophylaxis trial (PrEPVacc) to inform the estimation of HIV incidence in a counterfactual placebo arm.HIV research & clinical practice · 2025Trial
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- Leveraging infant visit PrEP screening INtegration & tasK shifting to improve post-partum HIV prevention in Malawi (LINK): a cluster-randomized trial evaluation of a postpartum HIV prevention package among breastfeeding women in Malawi.BMC health services research · 2025Trial
- Prenatal exposure to HIV pre-exposure prophylaxis and birth, growth, and social-emotional developmental outcomes throughout early childhood in Kenya: a prospective cohort study.The Lancet. Global health · 2025Trial
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- Evaluation of pharmacokinetics of Tenofovir Alafenamide (TAF) and Tenofovir Disoproxil (TDF) in pregnant and postpartum women in South Africa: PrEP-PP PK study.Antiviral research · 2024Trial
- Drug Concentrations in Hair and Dried Blood Spots as Preexposure Prophylaxis Adherence Metrics During Pregnancy and Postpartum.The Journal of infectious diseases · 2024Trial
- A risk-differentiated, community-led intervention to strengthen uptake and engagement with HIV prevention and care cascades among female sex workers in Zimbabwe (AMETHIST): a cluster randomised trial.The Lancet. Global health · 2024Trial
- The impact of intimate partner violence on PrEP adherence among U.S. Cisgender women at risk for HIV.BMC public health · 2024Trial
- Behavioral Modeling and its Association with PrEP and ART Use in Ugandan HIV-Serodifferent Couples.AIDS and behavior · 2024Trial
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- How a menu of adherence support strategies facilitated high adherence to HIV prevention products among adolescent girls and young women in sub-Saharan Africa: a mixed methods analysis.Journal of the International AIDS Society · 2023Trial
152 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
14 authors at 3 institutions in 1 country.
Funding
Abstract
Studies of daily emtricitabine-tenofovir disoproxil fumarate (FTC-TDF) for HIV preexposure prophylaxis (PrEP) in men who have sex with men (MSM) modeled intracellular tenofovir-diphosphate (TFV-DP) in dried blood spots (DBS) to assess adherence and corresponding PrEP outcomes. We conducted a prospective, randomized, crossover pharmacokinetic study of TFV-DP in DBS during 33%, 67%, or 100% of daily dosing under directly observed therapy (DOT). Participants were assigned to two 12-week dosing regimens, separated by a 12-week washout. Forty-eight adults (25 women) from Denver and San Francisco were included. TFV-DP exhibited a median half-life of 17 days, reaching steady state in 8 weeks. TFV-DP was dose proportional with mean (SD) steady-state concentrations of 530 (159), 997 (267), and 1,605 (405) fmol/punch for the 33%, 67%, and 100% arms, respectively. Prior work in MSM demonstrated clinically meaningful TFV-DP thresholds of 350, 700, and 1,250 fmol/punch, which were estimated 25th percentiles for 2, 4, and 7 doses/week. In the present study, corresponding TFV-DP was within 3% of the prior estimates, and subgroups by site, race, and sex were within 14% of prior estimates, although males had 17.6% (95% confidence intervals [CIs], 6.5, 27.4%) lower TFV-DP than females. The thresholds of 350, 700, and 1,250 fmol/punch were achieved by 75% of men taking ≥1.2, 3.2, and 6 doses/week and 75% of women taking ≥0.6, 2.0, and 5.3 doses/week, indicating that lower dosing reached these thresholds for both sexes. In conclusion, TFV-DP arising from DOT was similar to previous estimates and is useful for interpreting PrEP adherence and study outcomes. (This study has been registered at ClinicalTrials.gov under identifier NCT02022657.).
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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.