Formulary forum -: Domperidone:: A peripherally acting dopamine2-receptor antagonist

OBJECTIVE: TO review the pharmacology, pharmacokinetics, efficacy, and safety of domperidone in the treatment of gastrointestinal motility disorders and emesis. DATA SOURCES: MEDLINE and Excerpta Medica online databases were searched to identify published reports. STUDY SELECTION: Domperidone has been marketed worldwide outside the US since 1978, and extensive clinical data for this drug are available. This review focuses on the clinical experience from controlled studies of domperidone in the treatment of motility disorders, particularly diabetic gastroparesis. Also, case reports are used in summarizing safety. The control comparator groups included placebo or other prokinetic drugs (metoclopramide and cisapride). Controlled clinical trials of domperidone's efficacy and safety as an antiemetic are also briefly examined. Although a variety of domperidone dosage forms have been marketed, data generated from trials using the 10-mg tablet are highlighted because this is the only dosage form available in Canada and is under investigation in the US. DATA EXTRACTION: Because symptoms do not correlate with objective measures of gastrointestinal motility and they are the primary reason that patients with motility disorders seek treatment, the primary outcome extracted from the clinical studies was symptomatic response to treatment. Safety and efficacy between domperidone and placebo, metoclopramide, or cisapride were compared. DATA SYNTHESIS: Domperidone, a peripheral dopamine(2)-receptor antagonist, regulates the motility of gastric and small intestinal smooth muscle and has been shown to have some effects on the motor function of the esophagus. It also has antiemetic activity as a result of blockade of dopamine receptors in the chemoreceptor trigger zone. In controlled clinical trials, domperidone provided better relief of symptoms (anorexia, nausea, vomiting, abdominal pain, early satiety, bloating, distension) than placebo in patients with symptoms of diabetic gastropathy; symptomatic improvement was similar with domperidone and metoclopramide or cisapride. Domperidone also provided short-term relief of symptoms in patients with dyspepsia or gastroesophageal reflux, prevented nausea and vomiting associated with emetogenic chemotherapy, and prevented the gastrointestinal and emetic adverse effects of antiparkinsonian drugs. Because very little domperidone crosses the blood-brain barrier, reports of central nervous system adverse effects, such as dystonic reactions, are rare. CONCLUSIONS: Domperidone is a unique gastrokinetic and antiemetic drug. Because of its favorable safety profile, domperidone appears to be an attractive alternative to metoclopramide. In the management of diabetic gastropathy, domperidone's antiemetic activity distinguishes it from cisapride.