Favipiravir Pharmacokinetics and Drug Interaction Concerns for COVID-19 Trials
This early-pandemic review summarised the pharmacokinetic profile of favipiravir, an RNA-dependent RNA polymerase inhibitor repurposed from influenza to SARS-CoV-2. It flagged key drug-drug interaction risks through aldehyde oxidase and xanthine oxidase metabolism and dose-dependent nonlinear kinetics that complicated trial design. For clinical laboratories, the paper highlighted the importance of therapeutic drug monitoring when repurposing antivirals with complex PK in critically ill patients.
The original study
Favipiravir: Pharmacokinetics and Concerns About Clinical Trials for 2019-nCoV Infection.
- Authors
- Du YX, Chen XP
- Journal
- Clinical pharmacology and therapeutics
- Type
- Journal Article, Research Support, Non-U.S. Gov't, Review
- PMID
- 32246834
Original abstract
An outbreak of 2019-nCoV infection has spread across the world. No specific antiviral drugs have been approved for the treatment of COVID-2019. In addition to the recommended antiviral drugs, such as interferon-ɑ, lopinavir/ritonavir, ribavirin, and chloroquine phosphate, some clinical trials focusing on virus RNA-dependent RNA polymerase (RdRp) inhibitors have been registered and initiated. Favipiravir, a purine nucleic acid analog and potent RdRp inhibitor approved for use in influenza, is also considered in several clinical trials. Herein, we summarized the pharmacokinetic characteristics of favipiravir and possible drug-drug interactions from the view of drug metabolism. We hope this will be helpful for the design of clinical trials for favipiravir in COVID-2019, as data regarding in vitro virus inhibition and efficacy in preclinical animal studies are still not available.