Favipiravir Use in COVID-19: Analysis of Suspected Adverse Drug Events Reported in the WHO Database

Background: COVID-19 caused by SARS-CoV-2 virus emerged as an unprecedented challenge to discover effective drugs for its prevention and cure. Hyperinflammation-induced lung damage is one of the poor prognostic indicators causing a higher rate of morbidity and mortality of COVID-19 patients. Favipiravir, an antiviral drug, is being used for COVID-19 treatment, and we currently have limited information regarding its efficacy and safety. Thus, the present study was undertaken to evaluate the adverse drug events (ADEs) reported in the WHO pharmacovigilance database. Methods: This study analyzed all suspected ADEs related to favipiravir reported from 2015. The reports were analyzed based on age, gender, and seriousness of ADEs at the System Organ Classification (SOC) level and the individual Preferred Term (PT) level. Results: This study is based on 194 ADEs reported from 93 patients. Most frequent ADEs suspected to be caused by the favipiravir included increased hepatic enzymes, nausea and vomiting, tachycardia, and diarrhea. Severe and fatal ADEs occurred more frequently in men and those over the age of 64 years. Blood and lymphatic disorders, cardiac disorders, hepatobiliary disorders, injury poisoning, and procedural complications were more common manifestations of severe ADEs. Conclusion: This study revealed that favipiravir appears to be a relatively safe drug. An undiscovered anti-inflammatory activity of favipiravir may explain the improvement in critically ill patients and reduce inflammatory markers. Currently, the data is based on very few patients. A more detailed assessment of the uncommon ADEs needs to be analyzed when more information will be available.