Domperidone monomaleate

Domperidone (R33812) monomaleate is an orally active and selective dopamine-2 receptor antagonist. Domperidone monomaleate acts as an antiemetic and a prokinetic agent through its effects on the chemoreceptor trigger zone and motor function of the stomach and small intestine.

Cardiac Na⁺ channels are common targets of therapeutics inducing cardiotoxicity^[3].
Domperidone monomaleate (0-1000 μM) displays concentration- and state-dependent inhibitory of Nav1.5 in Human embryonic kidney HEK293 cells^[3].
Domperidone monomaleate (0, 10, 100 μM) displays tonic and use-dependent block to Na currents in rat cardiomyocytes with a IC₅₀ of 312 μM^[3].

Unlike Metoclopramide, Domperidone monomaleate does not cause any adverse neurological symptoms as it has minimal penetration through the blood-brain barrier^[1].
Domperidone monomaleate acts as both an antiemetic and an upper gastrointestinal tract prokinetic agent. It is rapidly absorbed after oral administration, and few side effects have been reported^[2].

References:
[1]. Reddymasu SC, et al. Domperidone: review of pharmacology and clinical applications in gastroenterology. Am J Gastroenterol. 2007;102(9):2036-2045.
[2]. Champion MC, et al. Domperidone, a new dopamine antagonist. CMAJ. 1986;135(5):457-461.
[3]. Stoetzer C, et al. Cardiotoxic Antiemetics Metoclopramide and Domperidone Block Cardiac Voltage-Gated Na+ Channels. Anesth Analg. 2017 Jan. 124(1):52-60.