ArticleThe Journal of antimicrobial chemotherapy2021
Pharmacokinetic modelling to estimate intracellular favipiravir ribofuranosyl-5'-triphosphate exposure to support posology for SARS-CoV-2.
Article in The Journal of antimicrobial chemotherapy, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 14 papers.
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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.
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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.
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Who cites it
14 citing papers in PubMed, 27 citations in OpenAlex.
- Favipiravir for Lassa fever: an open-label, randomized controlled phase 2 trial.Nature medicine · 2026Trial
- Optimal Dose and Safety of Intravenous Favipiravir in Hospitalized Patients With COVID-19: A Dose-Escalating, Randomized Controlled Phase Ib Study.Clinical pharmacology and therapeutics · 2026Trial
- Early treatment of Favipiravir in COVID-19 patients without pneumonia: a multicentre, open-labelled, randomized control study.Emerging microbes & infections · 2022Trial
- Favipiravir, lopinavir-ritonavir, or combination therapy (FLARE): A randomised, double-blind, 2 × 2 factorial placebo-controlled trial of early antiviral therapy in COVID-19.PLoS medicine · 2022Trial
- The relationship between plasma favipiravir concentrations and clinical outcomes in COVID-19.ERJ open research · 2026Article
- Favipiravir pharmacokinetics in Thai adults with mild COVID-19: A sub-study of interpatient variability and ethnic differences in exposure.Pharmacology research & perspectives · 2024Article
- A novel LC-MS/MS method for the determination of favipiravir ribofuranosyl-5'-triphosphate (T-705-RTP) in human peripheral mononuclear cells.Journal of pharmaceutical and biomedical analysis · 2024Article
- Article
- Favipiravir treatment in non-severe COVID-19: promising results from multicenter propensity score-matched study (FAVICOV).Scientific reports · 2023Article
- Development and validation of an LC-MS/MS method for quantification of favipiravir in human plasma.Journal of pharmaceutical and biomedical analysis · 2023Article
- The Real-World Clinical Outcomes of Favipiravir Treatment with Telemedicine Monitoring in Preventing Disease Progression in Mild to Moderate COVID-19 Patients; A Retrospective Cohort Study.Medicina (Kaunas, Lithuania) · 2023Observational
- Article
- Emerging small molecule antivirals may fit neatly into COVID-19 treatment.Drugs & therapy perspectives : for rational drug selection and use · 2022Review
- Development of a highly sensitive bioanalytical assay for the quantification of favipiravir.bioRxiv : the preprint server for biology · 2021Article
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Authors and funding
4 authors at 1 institution in 1 country.
Funding
Abstract
objectivesFavipiravir has discrepant activity against SARS-CoV-2 in vitro, concerns about teratogenicity and pill burden, and an unknown optimal dose. This analysis used available data to simulate the intracellular pharmacokinetics of the favipiravir active metabolite [favipiravir ribofuranosyl-5'-triphosphate (FAVI-RTP)].
methodsPublished in vitro data for intracellular production and elimination of FAVI-RTP in Madin-Darby canine kidney cells were fitted with a mathematical model describing the time course of intracellular FAVI-RTP as a function of favipiravir concentration. Parameter estimates were then combined with a published population pharmacokinetic model in Chinese patients to predict human intracellular FAVI-RTP. In vitro FAVI-RTP data were adequately described as a function of concentrations with an empirical model, noting simplification and consolidation of various processes and several assumptions.
resultsParameter estimates from fittings to in vitro data predict a flatter dynamic range of peak to trough for intracellular FAVI-RTP (peak to trough ratio of ∼1 to 1) when driven by a predicted free plasma concentration profile, compared with the plasma profile of parent favipiravir (ratio of ∼2 to 1). This approach has important assumptions, but indicates that, despite rapid clearance of the parent from plasma, sufficient intracellular FAVI-RTP may be maintained across the dosing interval because of its long intracellular half-life.
conclusionsPopulation mean intracellular FAVI-RTP concentrations are estimated to be maintained above the Km for the SARS-CoV-2 polymerase for 9 days with a 1200 mg twice-daily regimen (following a 1600 mg twice-daily loading dose on day 1). Further evaluation of favipiravir as part of antiviral combinations for SARS-CoV-2 is warranted.
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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.