Experimental evaluation of favipiravir (T-705)-induced liver and kidney toxicity in rats.

Favipiravir is an antiviral drug that selectively and potently inhibits RNA-dependent RNA polymerase of various RNA viruses. Its empirical use has increased with the COVID-19 pandemic. This study aimed to investigate the potential toxicological effects of favipiravir administration on healthy rats' liver and kidney tissues. Four groups were established in the survey (n = 10): Control, Low-dose favipiravir (100 mg/kg/d), Medium-dose favipiravir (200 mg/kg/d), and High-dose favipiravir (300 mg/kg/d). On the first day of the study, a loading dose equivalent to twice the maintenance dose was administered. On the eleventh day, liver and kidney tissues were collected for histopathological and immunohistochemical analyses. According to our results, favipiravir caused various histopathological damages in the liver and kidneys and led to alterations in the levels of cytokines associated with inflammation (IL-6, TGF-β, TNF-α, IL-1β, IFN-γ). Co-administration of favipiravir with various protective agents may be needed to mitigate potential damage to the liver and kidneys.