Domperidone

A dopamine antagonist used to improve gastric motility and control nausea.

What is Domperidone?

Domperidone is a peripheral dopamine D₂-receptor antagonist used as a prokinetic and antiemetic drug.

It enhances gastrointestinal motility without significant central effects.

History & Background

Domperidone was developed to provide anti-nausea benefits similar to metoclopramide but with fewer central nervous system side effects.

Chemical Structure & Properties

• IUPAC name: 5-chloro-1-[1-[3-(2-oxo-1-benzimidazolinyl)propyl]piperidin-4-yl]-1,3-dihydro-2H-benzimidazol-2-one
• Molecular formula: C₂₂H₂₄ClN₅O₂
• Molar mass: 425.91 g/mol
• Functional groups: Benzimidazolone, piperidine

Mechanism of Action

Domperidone blocks peripheral D₂ receptors, leading to:

• Increased gastric emptying
• Improved esophageal peristalsis
• Reduced nausea and vomiting

Pharmacokinetics

• Absorption: Moderate oral absorption
• Peak plasma time: 30–60 minutes
• Metabolism: Liver (CYP3A4)
• Half-life: ~7 hours
• Excretion: Feces and urine

Medical Uses

• Functional dyspepsia
• Gastroesophageal reflux disease (GERD)
• Nausea and vomiting
• Gastroparesis

Dosage Guidelines

Adults: 10 mg three times daily (before meals)

Maximum: 30 mg/day

⚠️ Avoid higher doses due to cardiac risk.

Side Effects

• Dry mouth
• Abdominal cramps
• Headache
• Increased prolactin levels

Warnings & Precautions

• Risk of QT prolongation
• Avoid in heart rhythm disorders
• Use lowest effective dose

Drug Interactions

• Macrolide antibiotics
• Azole antifungals
• Other QT-prolonging drugs

Frequently Asked Questions

Is domperidone safer than metoclopramide? – Fewer CNS effects.

Does it cause sleepiness? – Rare.

Can it be used long-term? – Short-term preferred.

Why is it restricted in some countries? – Cardiac safety concerns.

⚠️ Educational content only. Not a substitute for professional medical advice.