Motilium (Domperidone)

Motilium acts on the gastrointestinal motility pathway and is employed for several recognised conditions.

• Nausea and vomiting: reduces episodes of acute and chronic nausea and vomiting.
• Gastroparesis: accelerates gastric emptying and improves symptoms of delayed stomach emptying.
• Functional dyspepsia: alleviates upper abdominal discomfort and early satiety.
• Reflux disease: diminishes gastro‑oesophageal reflux by enhancing gastric clearance.

• Domperidone blocks peripheral dopamine D2 receptors located in the gastrointestinal tract and the chemoreceptor trigger zone. By inhibiting dopamine‑mediated inhibition, it increases smooth‑muscle contractility, promotes gastric emptying, and exerts anti‑emetic effects without significant central nervous system penetration.

Domperidone is generally well tolerated, but adverse reactions can occur.

Common Side Effects

• Dry mouth: reduced salivary flow causing throat discomfort.
• Abdominal cramps: mild gastrointestinal discomfort.
• Headache: transient tension‑type headache.
• Dizziness: occasional light‑headedness.
• Diarrhoea: loose stools.
• Constipation: reduced bowel movements.

Serious or Rare Side Effects

• Cardiac arrhythmia: irregular heart rhythm, especially with QT prolongation.
• Severe allergic reaction: rash, swelling, or anaphylaxis.
• Extrapyramidal symptoms: involuntary muscle movements.
• Hyperprolactinemia: elevated prolactin levels leading to galactorrhoea.
• QT interval prolongation: risk of torsades de pointes.
• Hepatic dysfunction: abnormal liver enzymes.

Domperidone requires careful consideration in specific patient groups and situations.

• Pregnancy: category B; use only if the potential benefit justifies the potential risk.
• Breastfeeding: minimal excretion in milk; monitor the infant for adverse effects.
• Cardiac risk: avoid in patients with known QT prolongation or cardiac arrhythmias.
• Hepatic or renal impairment: dose adjustment may be necessary; assess organ function.
• Drug interactions: review concomitant medications for known major interactions.
• Store at ambient temperature: keep below 25°C, retain in the original packaging, and protect from moisture.

Domperidone can affect, and be affected by, several other medicines.

Major Interactions (Avoid)

• Ketoconazole: potent CYP3A4 inhibition increases domperidone levels.
• Erythromycin: raises plasma concentration, heightening cardiac risk.
• Clarithromycin: similar CYP3A4 inhibition effect.
• HIV protease inhibitors (e.g., ritonavir): markedly elevate domperidone exposure.
• Other QT‑prolonging agents: additive risk of arrhythmia.

Moderate Interactions (Monitor Closely)

• Anticholinergics: may reduce gastrointestinal motility benefits.
• Other dopamine antagonists: potential additive central effects.
• CYP3A4 inducers (e.g., rifampicin): may lower domperidone efficacy.
• Antacids containing aluminium or magnesium: can impair absorption if taken simultaneously.
• SSRIs: monitor for increased risk of QT prolongation.