Investigation of the Frequency of Adverse Effects in Patients Treated with Favipiravir as SARS-CoV-2 Treatment

Objective: For 2019 and 2020, SARS-CoV-2 has been a sensational virus. Unfortunately, a treatment agent specific for SARS-CoV-2 has not been developed yet. Favipiravir is one of the antiviral agents used experimentally in the treatment of SARS-CoV-2. This study aimed to determine the frequency of side effects seen in patients hospitalized in our hospital and received favipiravir at any stage of their treatment. Methods: Our study is a retrospective observational study. Definite and probable COVID-19 cases hospitalized in our hospital between March 23, 2020, May 31, 2020, were determined, and those receiving favipiravir as initial or secondary therapy were included in the study. The demographic data, laboratory tests, observed side effects of the patients were recorded and analyzed statistically. Results: A total of 134 patients, 37.3% using favipiravir at the beginning and 62.7% as secondary, were included in the study. The mean age of the patients was 66.8±15.7 years. 38.1% (n=51) of the group were female. Side effects were detected in 17 (13%) patients in the whole group. Hepatotoxicity (4.5%), increased serum uric acid (4.5%), nephrotoxicity (1.5%), gastrointestinal side effects (1.5%), cardiac side effects (0.7%) were detected. There was no statistically significant difference in terms of adverse events between the patients who received favipiravir initially or later on disease course. Conclusions: Although some results support the short-term safety of favipiravir, more studies are needed for its long-term effects. Studies on hyperuricemia, QTc prolongation, use in pregnancy, use during lactation and use in children are insufficient. Therefore, although Favipiravir appears to be a good alternative in the treatment of COVID-19, it should be used carefully because the data on its safety is still insufficient. Key Words: Favipiravir, adverse effects, COVID-19, SARS-CoV-2