Domperidone is a dopamine antagonist that principally blocks the dopamine receptors located in the ChemoreceptorTrigger Zone (CTZ) and stomach. Its gastroprokinetic action is based on its blocking effect of dopamine receptors that have an influence on the motility of the gastrointestinal tract. Due to its weak penetration across the blood-brain barrier, Domperidone has almost no effect on the dopaminergic receptors in the brain, therefore, excluding psychotropic and neurologic side effects. Domperidone restores normal motility and tone of the upper gastrointestinal tract, facilitates gastric emptying, enhances antral and duodenal peristalsis and regulates contraction of the pylorus. Domperidone also increases esophageal peristalsis and lower esophageal sphincter pressure, and thus prevents regurgitation of gastric content.
Dyspeptic symptom complex, often associated with delayed gastric emptying, gastroesophageal reflux and esophagitis:
Epigastric sense of fullness, feeling of abdominal distension, upper abdominal pain
Eructation, flatulence, early satiety
Nausea and vomiting
Heartburn with or without regurgitations of gastric contents in the mouth
Non-ulcer dyspepsia
Acute nausea and vomiting of the functional, organic, infectious, dietetic origin or induced by radiotherapy or drug therapy or induced in migraine.
Parkinson's disease: In dopamine-agonist induced nausea and vomiting.
Radiological studies: Speeding barium transit in follow-through radiological studies.
Domperidone may reduce the risk of hypoprolactemic effect of bromocriptine. The action of Domperidone on Gl function may be antagonized by antimuscarinics and opoid analgesics. Care should be exercised when domperidone is administered in combination with MAO (monoamine oxidase) inhibitors.
Domperidone is contraindicated to patients having known hypersensitivity to this drug and in the case of neonates. Domperidone should not be used whenever gastrointestinal stimulation might be dangerous i.e., gastrointestinal hemorrhage, mechanical obstruction or perforation. Also contraindicated in patients with prolactin releasing pituitary tumor (prolactinoma).
Domperidone may produce hyperprolactinemia (1.3%).This may result in galactorrhea, breast enlargement, and soreness and reduced libido. Dry mouth (1%), thirst, headache (1.2%), nervousness, drowsiness (0.4%), diarrhea (0.2%), skin rash and itching (0.1%) may occur during treatment with domperidone. Extra-pyramidal reactions are seen in 0.05% of patients in clinical studies.
The safety of domperidone has not been proven and it is therefore not recommended during pregnancy. Animal studies have not demonstrated the teratogenic effect in the fetus. Domperidone may precipitate galactorrhea and improve post-natal lactation. It is secreted in breast milk but in very small quantities insufficient to be considered harmful.
Domperidone should be used with absolute caution in the case of children because there may be an increased risk of extra-pyramidal reactions in young children because of an incompletely developed blood-brain barrier. Since domperidone is highly metabolized in liver, it should be used with caution in patient with hepatic impairment.