Aim: To evaluate Corrected QT (QTc) interval prolongation (QTcP) in pediatric patients treated with voriconazole and identify its associated risk factors in this setting.
Methods: Clinical, voriconazole-related, and QTc data were collected retrospectively from the electronic medical records of voriconazole-treated pediatric patients attending a large tertiary medical center in 2011-2016 who underwent electrocardiography before and during therapy. Paired comparison of QTc intervals before and during voriconazole treatment was performed, adjusted for concurrent medications, electrolyte disturbances, and co-morbidities.
Results: Fifty-five patients (mean age 10.1±5.4 years) met the inclusion criteria; 34 had an oncologic or hemato-oncologic diagnosis. Mean QTc interval was 402.8±27.9 milliseconds (msec) before voriconazole treatment and 440.0±45.3 msec on treatment (p <0.001). During treatment, 38 patients (61.8%) had QTcP ≥30 msec and 17 (30.9%), QTcP ≥60 msec; 10 patients (18.2%) had QTc ≥500 msec of whom one acquired torsades de pointes. On multivariate analysis, older age (p=0.025), lower potassium level (p=0.025), and longer baseline QTc (0.032) were associated QTcP ≥60 msec, but not daily or cumulative dose of voriconazole.
Conclusion: This study demonstrated a high rate of clinically significant QTcP in voriconazole-treated children. Proper QTc monitoring, together with laboratory monitoring and electrolyte imbalance correction, is important to prevent cardiac arrhythmias in this patient population.
