Liver Injury in Favipiravir-Treated COVID-19 Patients: Retrospective Single-Center Cohort Study

(1) Background: Favipiravir (FVP) is a new antiviral drug used to treat COVID-19. It has been authorized to be used in the kingdom of Saudi Arabia in the treatment of COVID-19. The mechanism of action of FVP is working as a specific inhibitor for the RNA-dependent RNA polymerase of the RNA chain virus. FVP has the potential to be hepatotoxic because of the structure similarity with pyrazinamide. This retrospective study aimed to determine the prevalence of liver injury in FVP-treated COVID-19 patients in General East Jeddah Hospital, Saudi Arabia, during the COVID-19 pandemic. (2) Methods: A total of 6000 patients infected with COVID-19 and treated at the East Jeddah Hospital were included, with a sample size of 362 patients. The participants ranged from 18 to 70 years of age, both males and females, with normal hepatic and renal function and had a confirmed diagnosis of COVID-19 infection. Patients who had gouty arthritis, hepatic and renal dysfunction, dead patients, pregnant women, and breastfeeding mothers were all excluded from this study. A retrospective cohort study compared two groups of patients treated with and without FVP and who followed the Saudi Ministry of Health protocol to manage COVID-19 infection. (3) Results: An adverse effect of FVP on the liver was found that ranged from mild to severe. Stopping treatment with FVP was associated with an observed important increase in the levels of liver enzymes AST (p < 0.001), ALT (p < 0.001), alkaline phosphatase (p < 0.03), total bilirubin (p < 0.001), and direct bilirubin (p < 0.001) in the treated compared with the untreated group. (4) Conclusion: This study showed a significant difference between the treated and the untreated groups with FVP in liver injury. FVP influences the liver, increasing the blood levels of the liver function parameters.