CHLOROQUINE AND AZITHROMYCIN INDUCED QTC PROLONGATION IN COVID-19 PATIENTS

Abstract

Objective: To assess the degree of QTc interval prolongation caused by Chloroquine (CQ) alone and with Azithromycin in COVID-19 patients.

Study Design: Cross sectional comparative study.

Place and Duration of Study: Department of Medicine, Combined Military Hospital (CMH) Lahore, from Apr 2020 to May 2020.

Methodology: Data of the patients above 15 years of age who were confirmed COVID-19 cases and were prescribed chloroquine alone or in combination with Azithromycin were included. Baseline electrocardiograms (ECG) and ECGs recorded 48 hours after treatment initiation were collected. Retrospective analysis of ECGs (baseline and at 48 hours) was done. Patients were stratified into two groups: one on CQ alone, other on CQ and Azithromycin. Manual measurements of the QT interval were taken and QTc was calculated for each ECG. Baseline and follow up QTc intervals were compared using paired sample t-test. A QT prolongation of more than 20 milliseconds (msec) was considered significant.

Results: A total of 90 patients aged 15 and above were included in the study. The mean QTc in the CQ group raised from 411.2 ± 20.65 msec to 438.91 ± 20.43 msec with a mean difference of 27.23 msec and p-value of 0.001, which was a significant prolongation. In the CQ + Azithromycin group the mean QTc increased by 407.41 ± 21.17 msec to 440.85 ± 23.11 msec with a mean difference of 33.43 msec and p-value of 0.001. However no significant arrhythmia was observed in any patient.

Conclusion: Chloroquine alone as well as the combination chloroquine with Azithromycin causes significant QTc prolongation.