Safety Evaluation and Tolerability Overview of Favipiravir in the Management of COVID-19: A Real-Life Experience from Turkey

Introduction: Coronavirus diseases-2019 (COVID-19) have been ongoing for more than two years. Despite the scientific research conducted in this process, there is still no widely accepted definitive treatment for the disease. For treating COVID-19, using antiviral agents previously used for the treatment of other RNA-virus infections has been seen as a fast way to a solution, and favipiravir is one of the leading agents. This prospective, multicenter, observational study was designed to investigate the safety of favipiravir in 500 patients treated with favipravir for favipravir. Methods: This study was conducted as a multicenter prospective study. Eight different sites from four cities participated, and 500 patients were included in the study. Follow-up of laboratory parameters, adverse events (AEs), and amelioration of fever, dyspnea, and cough symptoms of the patients was recorded in a case report form. Results: A total of 475 patients from eight centers completed the study. A total of 401 AEs were reported in 206 (51.4%) patients, which were mild-to-moderate in the majority of cases. Serious AEs occurred in 5 patients and death occurred in 4 patients. From the first to the last measurement, serum alanine aminotransferase levels (31.9±27.7 vs. 47.2±49.7 U/L, p<0.001) increased, whereas C-reactive protein (39.9±66.4 vs. 15.2±30.5 mg/L, p<0.001) and creatine kinase (101.7±187.7 vs. 71.9±43.5 U/L, p=0.018) levels decreased. In follow-up parameters, oxygen saturation (SpO2; 96.2±2.7 vs. 97.5±2.1%, p<0.001) and amelioration of fever (>37.8 for 6.6% on day 3, 3.2% on day 5, and 0.6% on day 10), dyspnea (for 56.4% on day 5, 62.4% on day 7, and 81.2% on day 10), and cough (46.0% on day 5, 73.0% on day 7, and 87.3% on day 10) were noted in an increasingly higher percentage of patients with continued therapy. Conclusion: The current study provides real-life data of favipiravir, which is a unique option in Turkey for treating COVID-19 patients. The results revealed that favipiravir is a well-tolerated agent with a low side-effect profile. However, it needs to be evaluated with well-designed, dose-compared, randomized controlled studies for the evaluation of efficacy.