Increased ventilatory chemosensitivity induced by domperidone, a dopamine antagonist, in healthy humans.

Respiratory and cardiovascular effects of domperidone (0.1 mg X kg-1 i.v.) and placebo given on separate test days to eleven healthy volunteers were assessed in a double-blind study. Domperidone caused no significant change in ventilation, heart rate and blood pressure while they were resting and breathing room air. However, it produced an increase in the slope of the hypoxia-induced ventilatory response, from 2.35 +/- 1.10 to 3.71 +/- 2.91 1 X min-1 per 1% decrease in SaO2 (mean +/- SD; p less than 0.05). We conclude that domperidone augments hypoxic responsiveness in humans, presumably by blocking the dopaminergic receptors that modulate the activity of carotid body chemoreceptors, as it does not readily cross the blood-brain barrier.