Scopolamine Patch Safety in Patients with QTc Prolongation

Mechanism and Safety Profile

The American College of Cardiology notes that scopolamine is an anticholinergic medication that does not appear in any of the guidelines' lists of QT-prolonging medications 1
Unlike many other antiemetics, scopolamine does not have significant effects on cardiac repolarization, according to the American College of Cardiology and the Heart Rhythm Society 1, 2

Patients with QT prolongation should avoid medications explicitly known to prolong the QT interval, including certain antiemetics like 5-HT3 receptor antagonists, as recommended by the American College of Cardiology 2
Class III antiarrhythmic agents should be avoided in patients with QT prolongation, according to the American College of Cardiology 1
Citalopram may cause QT prolongation associated with Torsades de Pointes at daily doses exceeding 40 mg/d and should be avoided in patients with long QT syndrome, as noted by the American Academy of Child and Adolescent Psychiatry 3

The American College of Cardiology states that the risk of adverse cardiac events increases in patients with QT interval >500 ms 4
QT-prolonging medications should not be used in patients with long QT syndrome unless there is no suitable alternative, as recommended by the American College of Cardiology 4
Risk factors for torsades de pointes include female gender, hypokalemia, bradycardia, congestive heart failure, and baseline QT prolongation, according to the American College of Cardiology 1

If QTc >500 ms, exercise extra caution with any medication, as recommended by the American College of Cardiology 4
Choose scopolamine over other antiemetics for patients with QT prolongation, according to the American College of Cardiology and the Heart Rhythm Society 1, 2

In patients receiving cancer therapy with QT-prolonging agents, scopolamine is a safer antiemetic choice compared to 5-HT3 antagonists, as noted by the Ca-A Cancer Journal for Clinicians and the American College of Cardiology 2, 5
For patients with significant QT prolongation (>500 ms) who require antiemetic therapy, scopolamine is one of the preferred agents due to its lack of effect on the QT interval, according to the American College of Cardiology 1