Domperidone (R33812)(Motilium) is a dopamine blocker and an antidopaminergic reagent. It blocks the action of. It has strong affinities for the D2 and D3 dopamine receptors, which are found in the chemoreceptor trigger zone, located just outside the blood brain barrier, which - among others - regulates nausea and vomiting (area postrema on the floor of the fourth ventricle and rhomboid fossa).

Domperidone (a D2R antagonist) inhibits Equilibrative NT1 (ENT1) activity more in the presence than in the absence of Bromocriptine and displays an IC50 value lower than that of Bromocriptine or Ergovaline in Madin-Darby bovine kidney (MDBK) cells. [1]

Domperidone (0.1 mg/kg) results in a significant decrease in feeding behavior and stimulation of basal metabolism, but has no effect on locomotor activity of rats in a Phenomaster system. [2] Domperidone (1.1 mg/kg and 5.5 mg/kg, oral) significantly increases laminar microvascular blood flow (LMBF) in horses, compared with baseline values, beginning 4 hours after administration, and this effect persisted for at least 8 hours. Domperidone (0.2 mg/kg, i.v.) significantly increases laminar microvascular blood flow (LMBF) in horses, compared with baseline values, at 10 and 12 hours after administration. [3] Domperidone can ameliorate deleterious reproductive effects and reduce weight gain associated with fescue toxicosis in heifers. [4] Domperidone-treated mares have shorter gestation duration and foaled closer to their expected parturition date than did control mares. Domperidone-treated mares have higher Mammary gland scores and serum prolactin concentration. [5] Domperidone (5 mg/kg, oral) increases peak plasma acetaminophen concentration and area under the curve in rats, indicating increased gastric emptying. Domperidone decreases the dopamine-induced contractile activity of midjejunal longitudinal muscle strips in rats. [6]