The effect of favipiravir on QTc interval in patients hospitalized with coronavirus disease 2019

Background: The effect of favipiravir on the QTc interval during the treatment of Coronavirus Disease 2019 (COVID-19) patients is unclear. Thus, the current study objective was to evaluate any change in the QTc interval in patients who were hospitalized due to COVID-19 receiving favipiravir treatment.

Method: Patients hospitalized with COVID-19 were assessed in this single-center retrospective study. 189 patients, whose diagnosis was confirmed using real-time PCR, were included in the study. The patients were divided into three groups: those using hydroxychloroquine (Group 1, n = 66), hydroxychloroquine plus favipiravir (Group 2, n = 66), and favipiravir only (Group 3, n = 57). The QTc interval was measured before treatment (QTc-B) and 48 h after (i.e., the median) starting treatment (QTc-AT).

Results: The median age was 53 (39-66 IQR) and 97 (51%) of patients were female. The median QTc(Bazett)-change was 7 ms (p = 0.028) and 12 ms (p < 0.001) and in Group 1 and 2, respectively. In Group 3, the median QTc(Bazett)-change was observed as -3 ms and was not statistically significant (p = 0.247). In multivariable analysis, while there was a significant relationship between QTc-AT(Bazett) and hydroxychloroquine (β coefficient = 2687, 95%CI 2599-16,976, p = 0,008), there was no significant relationship with favipiravir (β coefficient = 0,180, 95% CI -6435-7724, p = 0,858). Similarly, there was a significant relationship between the QTc-AT interval calculated using the Fredericia formula and hydroxychloroquine (β coefficient = 2120, 95% CI 0,514-14,398, p = 0,035), but not with favipiravir (β coefficient = 0,111, 95% CI -6450- 7221, p = 0,911).

Conclusion: In the ECG recordings received in the following days after the treatment was started in COVID-19 patients, there was a significant prolongation in the QTc interval with hydroxychloroquine, but there was no significant change with favipiravir.