Domperidone in Parkinson's disease: a perilous arrhythmogenic or the gold standard?

Domperidone, a dopamine antagonist that does not easily cross the blood-brain barrier, is considered the gold standard for treating gastrointestinal symptoms in patients with Parkinson's disease (PD) because the risk of developing extrapyramidal adverse effects is considered minimal. On the other hand, cardiotoxicity related to domperidone is not a new issue. In fact, arrhythmias, sudden death and cardiac arrest were reported with high intravenous doses in the 80s. Concern about the cardiotoxicity of oral domperidone has arisen more recently after the publication of two case-control studies which have questioned domperidone's safety even further, especially in patients > 60 years and in doses >30 mg/day. Very little is known about domperidone's cardiac effects in patients with PD. In addtion, pharmacoepidemiological data about specific antiemetic use in these patients is scarce, with almost anecdotal reports of inappropriate centrally acting antidopaminergic drugs like metoclopramide in the hospital setting. As a result, and even no cases of serious arrhythmias or sudden cardiac death associated with domperidone concerning patients with PD have been reported, no definitive conclusions can be drawn about its safety. In conclusion, despite domperidone is still recognized as the first choice for treating gastrointestinal symptoms PD, doses above 30 mg/daily should only be considered with special caution taking into account its potential cardiotoxic effects.