Metoclopramide, domperidone: sudden cardiac death, ventricular arrhythmia

The results of two large epidemiological studies on the association between domperidone and ventricular arrhythmia or sudden cardiac death were published in 2015; one study was conducted in Taiwan and the other in the United Kingdom. They also examined metoclopramide. Both studies demonstrated an increased risk of sudden cardiac death and ventricular arrhythmia with metoclopramide, similar to the risk associated with domperidone. The results concerning domperidone were consistent with those of previous studies. In particular, they showed that the risk was higher with doses greater than 30 mg per day or with concomitant use of inhibitors of the cytochrome P450 isoenzyme CYP3A4, which reduce domperidone clearance. In practice, metoclopramide has a marginal role in patient care, with minor efficacy. Domperidone should not be used at all; its efficacy at the approved dose, beyond a placebo effect, is uncertain.