The safety profile of favipiravir in COVID-19 patients with severe renal impairment

Objective The safety profile of favipiravir in patients with severe renal impairment has not been investigated and available data are insufficient. The study aimed to compare the incidence of favipiravir-associated adverse events amongst patients with varying renal function statuses. Methods Records of 921 patients who were hospitalised for COVID-19 and had received at least 5 days of favipiravir treatment were retrospectively evaluated and 228 patients were included in the study. Patients' age, sex, comorbidities, estimated glomerular filtration rate (eGFR) and haematological and biochemical values were recorded. The incidence of adverse events was compared with the age, sex, comorbidities and eGFR of the patients. Results The mean age of the patients was 59.3 +/- 15.6 years, and 38.2% of the patients were women. One hundred and thirty-one (57.5%) patients had experienced adverse events. These adverse effects consisted of ALT elevation (35.5%), AST elevation (21.5%), anaemia (16.2%), hyperuricaemia (10.5%), hepatocellular injury (9.2%), neutropenia (3.5%) and thrombocytopenia (2.6%). The incidence of adverse events was not significantly different when patients had eGFR >60 mL/min/1.73 m(2) or eGFR 30-60 mL/min/1.73 m(2) (P > .05), but significantly increased when the eGFR dropped to <30 (P < .05). The differences seen with hyperuricaemia and anaemia were significant (P < .05). Conclusion Even though favipiravir appeared to be well tolerated in the individuals with renal failure in this study, its use in this population remains a challenge that requires more research and analysis.