Abstract
Favipiravir is an RNA polymerase inhibitor that was developed in Japan, and its antiviral effect is expected to be useful against coronavirus disease 2019 (COVID-19). We examined the therapeutic effect of favipiravir use for 6 patients with COVID-19. We analyzed body temperature, heart rate, blood pressure, respiratory rate, oxygen saturation, electrocardio- graphic changes, and clinical symptoms before and after oral administration of favipiravir. Normalization of body temperature (‹ 37 °C) was achieved by the third day of hospitalization by all patients. Heart rate reduction was observed after the start of treatment and was almost correlated with body temperature. Cough, fatigue, olfactory and gustatory dysfunction, headache, and digestive symptoms were observed on the first and second days of illness, but improved after the third day of illness. We examined changes in heart rate, PR interval, QRS duration, and QTc interval by electrocardiography. Favipiravir reduced heart rate and increased the PR interval for most patients;however, the QRS duration and QTc interval did not change except in one case. In conclusion, heart rate reduction by favipiravir was well-correlated with the clinical course;thus, heart rate could be a useful indicator of the therapeutic efficacy of favipiravir use for patients with COVID-19.
