QTc Interval Prolongation with IV Erythromycin in Gastroparesis Treatment

Patient Risk Factors

Pre-existing idiopathic QT prolongation is a risk factor for torsades de pointes with IV erythromycin, particularly in patients with hepatic dysfunction, myocardial ischemia, or left ventricular dysfunction 1
Age >80 years and female gender increase susceptibility to torsades de pointes with IV erythromycin 2

The British Thoracic Society recommends obtaining a baseline ECG to exclude QTc >450 ms (men) or >470 ms (women) before initiating IV erythromycin therapy 2
The British Thoracic Society suggests screening for risk factors, including history of heart disease, hypokalemia, bradycardia, family history of sudden death, or concurrent QT-prolonging medications 4
The European Society for Clinical Nutrition and Metabolism (ESPEN) guidelines recommend IV erythromycin (100-250 mg every 6-8 hours) as the first-line prokinetic for critically ill patients with gastroparesis and feeding intolerance, despite the QTc risk (Grade B recommendation) 6

Repeat ECG one month after initiation of IV erythromycin to detect development of prolonged QTc, and discontinue the drug immediately if QTc becomes prolonged 3
Limit duration of IV erythromycin to 2-4 days maximum, correct electrolyte abnormalities, and avoid concurrent QT-prolonging drugs 6, 1

For patients with pre-existing QTc prolongation or significant cardiac risk factors, metoclopramide should be used as the first-line alternative to IV erythromycin, as it carries substantially lower QTc risk 3