SCARY ARTICLE SENT TO ME BY A BASIC SCIENTIST FRIEND:

Domperidone Should Not Be Considered a No-Risk Alternative to Cisapride in 
the Treatment of Gastrointestinal Motility Disorders

Benoit Drolet, MSc; Guy Rousseau, PhD; Pascal Daleau, PhD; Rene´ Cardinal, 
PhD; Jacques Turgeon, PhD

Background—Several cases of QT prolongation and ventricular tachyarrhythmia 
have been reported with domperidone, a gastrokinetic and antiemetic agent 
available worldwide but still under investigation in the United States. Although 
electrolyte disturbances such as hypokalemia could account for some of these 
events, we hypothesized that domperidone
may have unsuspected electrophysiological effects predisposing some patients 
to proarrhythmia.

Methods and Results—Studies were undertaken in 9 isolated guinea pig hearts, 
which demonstrated reverse use–dependent prolongation of cardiac 
repolarization by 100 nmol/L domperidone. Action potential duration increased 27% from 
baseline with domperidone (from 11463 to 14562 ms) during pacing at a cycle length 
of 250 ms, and a 9% increase (from 9762 to 10663 ms) was seen with pacing at 
a cycle length of 150 ms. Experiments in human ether-a-go-go–related gene 
(HERG)-transfected Chinese hamster ovary cells (n532) demonstrated a 
concentration-dependent block of the rapid component (IKr) of the delayed rectifier 
potassium current. The tail current decreased by 50% at 162 nmol/L domperidone.

Conclusions—Domperidone possesses cardiac electrophysiological effects 
similar to those of cisapride and class III antiarrhythmic drugs. These effects are 
observed at clinically relevant concentrations of the drug. Therefore, 
domperidone should not be
considered a no-risk alternative to cisapride, a drug that was recently 
withdrawn from the US market. (Circulation. 2000;102:1883-1885.)
Key Words: arrhythmia n ion channels n torsade de pointes n electrophysiology 
n long-QT syndrome

ANYONE WHO WANTS THE FULL ARTICLE IN PDF, PLEASE EMAIL ME AND I WILL ATTACH 
IT.

Nancy
Nancy E. Wight MD, IBCLC, FAAP, FABM
Neonatologist
Children's Hospital and Sharp Mary Birch Hospital for Women
Medical Director, Sharp HealthCare Lactation Services
San Diego, CA 
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