The safety and adverse event profile of favipiravir in the treatment of COVID-19 patients, Turkey

Introduction: Favipiravir (FVP) is an antiviral and used to treat COVID-19. We aimed to document the safety and adverse events associated with FVP on the outcome of COVID-19 treatment.

Methodology: The study included 225 adult patients with moderate COVID-19 infection (World Health Organization scale-5). The adverse events (AEs) were evaluated using a grading scale supported by the Food and Drug Administration. Safety was assessed by the frequency of serious AEs.

Results: The AEs associated with FVP treatment were hepatotoxicity (87/225, 38.7%), weakness (32/225, 14.2%), nephrotoxicity (26/225, 11.6%), nausea (18/225, 8.0%), diarrhea (8/225, 3.6%), vomiting (5/225, 2.2%), and insomnia (4/225, 1.8%); rash was not detected. Hepatotoxicity was observed more frequently in patients who also developed nephrotoxicity (57.7% vs 36.2%, p = 0.03). The deceased patients were significantly older and had higher prevalence of hypertension, congestive heart failure (CHF), coronary artery disease, cancer, nephrotoxicity. and angiotensin- converting enzyme inhibitors/angiotensin receptor blocker use. While male gender (OR: 5.38 CI: 1.64-17.67) and CHF (OR: 6.8 CI: 1.92-24.74) were significantly associated with nephrotoxicity, age (OR: 1.06 CI: 1.02-1.10), cancer (OR: 3.9 CI: 1.10-14.22) and nephrotoxicity (OR: 5.5 CI: 1.74-17.74) were associated with mortality.

Conclusions: Serious AEs were detected at very low levels that would not require discontinuation of treatment or any AE-related death. Since SARS-CoV-2 itself and drug interactions may differ, FVP-related AEs might vary in COVID-19 patients. Our study shows that FVP can be used safely with a low AE profile. More extensive evidence is required to evaluate the long-term AEs of FVP.