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.