Motilium (Domperidone)

• Domperidone acts as a peripheral dopamine‑2 receptor antagonist, providing anti‑emetic and gastro‑prokinetic benefits in several gastrointestinal disorders.
• Nausea and vomiting: reduces episodes by enhancing gastric motility and blocking peripheral dopamine receptors.
• Gastroparesis: improves stomach emptying, alleviating delayed gastric transit symptoms in affected patients.
• Functional dyspepsia: relieves upper abdominal discomfort, fullness and early satiety through accelerated gastric clearance.
• Gastro‑oesophageal reflux disease: decreases reflux episodes by promoting faster gastric emptying and reducing gastric volume.
• Chemotherapy‑induced nausea: provides adjunct anti‑emetic support when standard regimens are insufficient.

• Domperidone exerts its effect by selectively blocking dopamine‑D2 receptors located on the chemoreceptor trigger zone and in the gastrointestinal tract. Peripheral antagonism prevents dopamine‑mediated inhibition of acetylcholine release, thereby increasing gastrointestinal motility and accelerating gastric emptying. The central anti‑emetic action is limited because the molecule does not readily cross the blood‑brain barrier, reducing central side effects. This peripheral selectivity contributes to its favorable safety profile compared with centrally acting dopamine antagonists.

Domperidone may cause a range of adverse reactions, which are categorized by frequency and severity.

Common Side Effects

• Dry mouth: reduced salivary secretion leading to a feeling of thirst.
• Abdominal cramps: mild to moderate discomfort in the stomach area.
• Headache: transient pain often described as throbbing.
• Dizziness: sensation of light‑headedness, especially upon standing.

Serious or Rare Side Effects

• Cardiac arrhythmia: irregular heart rhythm that may require medical attention.
• QT interval prolongation: potential for serious ventricular tachyarrhythmias.
• Severe allergic reaction: rash, swelling, or anaphylaxis requiring immediate care.
• Extrapyramidal symptoms: involuntary muscle movements or tremor.

Before prescribing domperidone, clinicians should evaluate several safety considerations to minimize risk.

• Assess cardiac risk: obtain baseline ECG to check QT interval in patients with cardiac history.
• Avoid in patients with known arrhythmias: domperidone can exacerbate rhythm disturbances.
• Use caution with hepatic impairment: reduced metabolism may increase drug exposure.
• Monitor electrolyte balance: hypokalemia can heighten risk of QT prolongation.
• Limit duration: prescribe the shortest effective course to reduce cumulative exposure.
• Store at ambient temperature: keep below 25 °C in the original packaging, protected from moisture.

Domperidone interacts with several medicines that affect its metabolism or cardiac safety profile.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., ketoconazole, erythromycin): may raise domperidone plasma levels and increase cardiac toxicity.
• Other QT‑prolonging agents (e.g., quinidine, sotalol): combined use can markedly extend QT interval.

Moderate Interactions (Monitor Closely)

• CYP3A4 inducers (e.g., rifampicin, carbamazepine): may lower domperidone concentrations, reducing efficacy.
• Anticholinergic drugs (e.g., atropine): may enhance gastrointestinal side effects.
• Other antiemetics (e.g., metoclopramide): additive dopamine antagonism may increase adverse effects.