Evaluation of cardiac arrhythmia incidence in patients treated with oral moxifloxacin

Abstract

Background: The effect of moxifloxacin on QT interval is reversible and dose related, mainly provided by weakly but rapidly activated rectifying potassium channel blockade, IKr or human ether-a-go-go-related gene potassium channels. Retrospective data suggested an increase in cardiac event rates with moxifloxacin use. Nevertheless, except for case reports and experimental trials about QT/QTc, there are insufficient data in the literature on the incidence of cardiac arrhythmias detected by electrocardiography (ECG) and Holter monitoring. In this trial, we sought to determine the effects of newly administrated oral moxifloxacin on the incidence of cardiac arrhythmias. Methods: Forty-four patients (mean age 34.0 ± 10.4 years) treated with oral moxifloxacin with the indications of upper airway infections, community-acquired pneumonia, and acute exaggerated bronchitis were enrolled. All patients were screened for cardiac arrhythmia before therapy (BT) (0th day), on the 3rd day (during therapy [DT]), and on the 10th day (after therapy [AT]) with ECG and on the 3rd and 10th day with Holter monitorization. Before starting of the therapy, structural heart diseases were excluded using echocardiography, and other exclusion criteria were based on the laboratory tests.Results: The mean heart rate (HR) assessed by Holter monitoring was not significantly different during and after antibiotic therapy, although the mean HR measured from surface ECG was significantly reduced during and after antibiotic therapy compared to baseline (BT: 80.3 ± 13.9 beats per minute [BPM] vs. DT: 76.3 ± 11.3 vs. BPM vs. AT: 75.9 ± 106.0 BPM; P = 0.007). The mean QT interval value was increased on the 3rd day when compared to 0th day and was similar with the value on the 10th day (BT: 353.1 ± 24.6 msn vs. DT: 363.3 ± 23.7 msn vs. AT: 361.8 ± 20.8 msn; P = 0.034). The mean QTc interval was significantly increased on the 3rd day; however, it was decreased to the baseline value AT (BT: 396.4 ± 20.2 msn vs. DT: 404.4 ± 19.3 msn vs. AT: 397.5 ± 21.0 msn; P = 0.011). When the Holter monitoring findings of our study were analyzed in terms of gender interaction, minimal and maximal HR and QT dispersion parameters as well as the frequencies of ventricular and supraventricular extrasystoles and other arrhythmia findings were not different between male and females. Conclusion: Oral moxifloxacin started on an outpatient basis with the indication of airway infections resulted in a temporary increase in QT interval DT. However, it does not affect QTc and is not related with serious cardiac arrhythmias during Holter monitoring.

Keywords

• Arrhythmia
• electrocardiography
• Holter monitoring
• moxifloxacin
• QT dispersion
• QT/QTc interval