The impact of hydroxychloroquine–azithromycin combination on Tpeak‐to‐end and Tpeak‐to‐end/QT ratio during a short treatment course

BACKGROUND: Since there was no proven treatment of coronavirus disease 2019 (COVID‐19), hydroxychloroquine–azithromycin (HCQ‐AZM) combination is being used in different countries as a treatment option. Many controversies exist related to the safety and effectiveness of this combination, and questions about how HCQ‐AZM combination affects the ventricular repolarization are still unknown. OBJECTIVE: The aim of the study was to show whether the hydroxychloroquine–azithromycin (HCQ‐AZM) combination prolonged Tpeak‐to‐end (TpTe) duration and TpTe/QT interval ratio or not. METHODS: One hundred and twenty‐six consequent COVID‐19(+) patients meeting the study criteria were enrolled in this study. Baseline ECGs were obtained immediately after hospitalization and before commencing the HCQ‐AZM combination. On‐treatment ECG was obtained 24–48 hr after the loading dose of HCQ/AZM. ECG parameters including PR interval, QRS duration, QT interval, QTc interval, TpTe duration, and TpTe/QT interval ratio were assessed. Demographic and laboratory findings were collected from an electronic recording system. RESULTS: ECGs of 126 COVID‐19(+) patients who received HCQ‐AZM combination were assessed. Mean baseline QTc (by Fridericia formula), TpTe, and TpTe/QT ratio were 420.0 ± 26.5 ms, 82.43 ± 9.77 ms, and 0.22 ± 0.02, respectively. On‐treatment QTc, TpTe and TpTe/QT ratio were 425.7 ± 27.18 ms, 85.17 ± 11.17 ms, and 0.22 ± 0.03, respectively. No statistically significant acute impacts of HCQ‐AZM combination on TpTe duration and TpTe/QT interval ratio were observed compared with baseline values. No ventricular tachycardia/fibrillation and the significant conduction delays were seen during in‐hospital follow‐up. CONCLUSION: HCQ‐AZM combination increased TpTe duration. However, no significant impact on TpTe/QT interval ratio was observed.