Interpretation of Hepatotoxic Side Effects by Rcv (Reference Change Value) in Covid-19 Patients Treated with Favipiravir

ABSTRACT

Objectives: Favipiravir was first used against SARS-CoV-2 in Wuhan at the very epicenter of the pandemic. Its side effects include hyperuricemia, decreased neutrophil counts, diarrhea, and increased alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkalen phospatase ALP, bilirubin. Reference change value (RCV) represents the clinical significance of the variation between the RESULTS of two consecutive tests and laboratory test results exceeding this value are associated with the individual's disease status. In this study, we evaluated the side effects of favipiravir treatment on AST and ALT using RCV. Materials-Methods: We examined retrospectively 40 patients were administered 1600 mg of favipiravir twice daily on day 1, followed by 600 mg twice daily from day 2 to day 5 (or more if needed). The analytic coefficient of variation (CVA0,47 for AST 0,42 for ALT) was calculated from internal quality control RESULTS. Intra-individual coefficient of variation (CVI) and inter-individual coefficient of variation (CVG) were obtained from Westgard's website, which was updated in 2014.The RCV% is calculated with the following formula Zx21/2x[CVA2+CVI2]1/2 (Using an unidirectional probability of 95%, Z=1.65). Result(s) The RCV% results were calculated as %28 for AST and % 45 for ALT.The individuality index (II) was calculated as 0.532 for AST and 0.466 for ALT. ALT and AST values were evaluated as higher than the calculated RCV value in 70%,62,5% of the patients. Conclusion(s) The use of RCV is recommended as a valuable tool in the follow-up of patient results and side effects of treatment.