A Prospective study of QTC prolongation due to Erytrhomycin used as Prokinetic agent in Icu Patients

A ProSPeCTiVe STudy of QTC ProloNgATioN due To eryTrhomyCiN uSed AS ProkiNeTiC AgeNT iN iCu PATieNTS R.B. Fiets; J.M. Bos; R. Donders; M. Bruns; E.J. Lamfers; J.A. Schouten; and C. Kramers Radboud University Medical Center, Nijmegen, the Netherlands; and Canisius Wilhelmina Hospital, Nijmegen, the Netherlands Background: High dose erythromycin used as antibiotic prolongs QTc. Low dose erythromycin is frequently used as a prokinetic agent, especially in patients at the ICU. It is unknown whether low dose erythromycin prolongs QTc and put patients at risk for torsades des pointes. Methods: In this prospective study we included patients at the ICU treated with erythromycin in a dose of 200 mg bd. Electrocardiogram was registered before, 15 minutes and 24 hours after start of erythromycin. No new QTc medication should be started during study. QTc was measured by 2 investigators. Electrolytes, renal function and hepatic function was measured in all patients. Results: In a total of 51 patient, 3 ECGs were recorded and no change was made in QTc prolonging medication. In these 51 patients QTc increased significantly from 430 ms at baseline to 439 ms (p = 0.03) after 15 minutes and 444 ms (p = 0.01) after 24 hours. After 15 minutes and 24 hours upper limit of 95% confidence interval for prolongation of QTc was well above 10 ms. In 4 patients QTc increased to more than 500 ms and in 2 patients QT was already above 500 ms. No QTc related arrhythmias were seen. Conclusion: Erythromycin in a dose of 200 mg bd prolongs QTc and ECG should be controlled when this is prescribed.