Trial reportClinical pharmacology and therapeutics2015
Pharmacokinetic and Pharmacodynamic Comparison of Once-Daily Efavirenz (400 mg vs. 600 mg) in Treatment-Naïve HIV-Infected Patients: Results of the ENCORE1 Study.
Trial report in Clinical pharmacology and therapeutics, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 51 papers, 1 of them a synthesis 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.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
51 citing papers in PubMed, 1 synthesis or guideline pooled it, 72 citations in OpenAlex.
- Pharmacokinetics of efavirenz in patients on antituberculosis treatment in high human immunodeficiency virus and tuberculosis burden countries: A systematic review.British journal of clinical pharmacology · 2018Pooled it
- Decreased Dolutegravir and Efavirenz Concentrations With Preserved Virological Suppression in Patients With Tuberculosis and Human Immunodeficiency Virus Receiving High-Dose Rifampicin.Clinical infectious diseases : an official publication of the Infectious Diseases Society of America · 2023Trial
- Pharmacokinetics of Ruxolitinib in HIV Suppressed Individuals on Antiretroviral Agent Therapy from the ACTG A5336 Study.Journal of clinical pharmacology · 2021Trial
- Pharmacokinetics and Drug-Drug Interactions of Isoniazid and Efavirenz in Pregnant Women Living With HIV in High TB Incidence Settings: Importance of Genotyping.Clinical pharmacology and therapeutics · 2021Trial
- Comprehensive Pharmacokinetic, Pharmacodynamic and Pharmacogenetic Evaluation of Once-Daily Efavirenz 400 and 600 mg in Treatment-Naïve HIV-Infected Patients at 96 Weeks: Results of the ENCORE1 Study.Clinical pharmacokinetics · 2016Trial
- Why Did I Stop? Barriers and Facilitators to Uptake and Adherence to ART in Option B+ HIV Care in Lilongwe, Malawi.PloS one · 2016Trial
- Pharmacokinetics of Efavirenz in Pregnancy and Postpartum with and Without First-line Tuberculosis Drugs: Results from IMPAACT P1026s.Clinical pharmacokinetics · 2026Article
- Virologic Outcomes of Common First-Line Antiretroviral Regimens Among Adults with HIV - China, 2021-2023.China CDC weekly · 2026Article
- Pharmacogenomics of antibacterial and antiviral therapies: Clinical actionability, evidence gaps, and future directions.Pharmacological reviews · 2026Review
- CYP2B6 polymorphisms and suicidal behaviour in people living with HIV treated with efavirenz-containing combination antiretroviral therapy: a global case-control study.Frontiers in pharmacology · 2026Article
- Modelling the impact of initiation delay, duration and prior PrEP on the efficacy of post-exposure prophylaxis containing a tenofovir/emtricitabine backbone.Journal of the International AIDS Society · 2025Article
- Determining Targets for Antiretroviral Drug Concentrations: A Causal Framework Illustrated With Pediatric Efavirenz Data From the CHAPAS-3 Trial.Pharmacoepidemiology and drug safety · 2024Article
- PBPK Modeling of Lamotrigine and Efavirenz during Pregnancy: Implications for Personalized Dosing and Drug-Drug Interaction Management.Pharmaceutics · 2024Article
- A Physiologically-Based Pharmacokinetic Simulation to Evaluate Approaches to Mitigate Efavirenz-Induced Decrease in Levonorgestrel Exposure with a Contraceptive Implant.Pharmaceutics · 2024Article
- Article
- Efavirenz: History, Development and Future.Biomolecules · 2022Review
- Predictors of Efavirenz Plasma Exposure, Auto-Induction Profile, and Effect of Pharmacogenetic Variations among HIV-Infected Children in Ethiopia: A Prospective Cohort Study.Journal of personalized medicine · 2021Article
- PharmVar GeneFocus: CYP2B6.Clinical pharmacology and therapeutics · 2021Review
- Mechanistic Modeling of Maternal Lymphoid and Fetal Plasma Antiretroviral Exposure During the Third Trimester.Frontiers in pediatrics · 2021Article
- Prevalence of Cytochrome P450 2B6 Single Nucleotide Polymorphism in an HIV-Positive Cohort in Jos, Nigeria: Implication for HIV Therapy.Nigerian journal of clinical practice · 2020Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
17 authors at 6 institutions in 5 countries.
Funding
Abstract
Daily efavirenz 400 mg (EFV400) was virologically noninferior to 600 mg (EFV600) at 48 weeks in treatment-naïve patients. We evaluated EFV400 and EFV600 pharmacokinetics (NONMEM v. 7.2), assessing patient demographics and genetic polymorphisms (CYP2B6, CYP2A6, CYP3A4, NR1I3) as covariates and explored relationships with efficacy (plasma HIV-RNA (pVL) <200 copies/mL) and safety outcomes at 48 weeks in 606 randomized ENCORE1 patients (female = 32%, African = 37%, Asian = 33%; EFV400 = 311, EFV600 = 295). CYP2B6 516G>T/983T>C/CYP2A6*9B/*17 and weight were associated with efavirenz CL/F. Exposure was significantly lower for EFV400 (geometric mean ratio, GMR; 90% confidence interval, CI: 0.73 (0.68-0.78)) but 97% (EFV400) and 98% (EFV600) of evaluable pVL was <200 copies/mL at 48 weeks (P = 0.802). Four of 20 patients with mid-dose concentrations <1.0 mg/L had pVL ≥200 copies/mL (EFV400 = 1; EFV600 = 3). Efavirenz exposure was similar between those with and without efavirenz-related side effects (GMR; 90% CI: 0.95 (0.88-1.02)). HIV suppression was comparable between doses despite significantly lower EFV400 exposure. Comprehensive evaluation of efavirenz pharmacokinetics/pharmacodynamics revealed important limitations in the accepted threshold concentration.
Indexed as
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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.