Domperidone Tablets

Mechanism

Domperidone blocks peripheral dopamine (D2) receptors in the gastrointestinal tract. This enhances gastric emptying, increases lower esophageal sphincter tone, and reduces nausea and vomiting. Unlike metoclopramide, it has limited penetration into the CNS, reducing risk of sedation or extrapyramidal effects.

Pharmacodynamics:

Like other 2nd generation antihistamines, loratadine is selective for peripheral H1 receptors.Loratadine does not penetrate effectively into the central nervous system and has poor affinity for CNS H1-receptors.These qualities result in a lack of CNS depressant effects such as drowsiness, sedation, and impaired psychomotor function. The onset of action varies significantly and clinical efficacy is not always directly related to only the H1 receptor potency, as concentration of free drug at the receptor must also be considered.

Pharmacokinetics

• Absorption: Rapid oral absorption; bioavailability ~15% due to first-pass metabolism.
• Distribution: Widely distributed; protein binding ~90–95%.
• Metabolism: Extensive hepatic metabolism via CYP3A4.
• Elimination: Excreted in urine and feces.
• Half-life: ~7–9 hours.

Side Effects

• Headache
• Dizziness
• Dry mouth
• Abdominal discomfort
• Diarrhea
• Rare: QT prolongation, arrhythmias

Contraindication

• Hypersensitivity to Domperidone
• Moderate/severe hepatic impairment
• Cardiac conduction abnormalities (QT prolongation)
• Concomitant use with potent CYP3A4 inhibitors

Interaction

• Ketoconazole, erythromycin (increase plasma levels, QT risk)
• Other QT-prolonging drugs
• Alcohol (enhances dizziness)

Warning and Precautions

• Use under medical supervision only
• Limit duration to ≤1 week due to cardiac risks
• Caution in elderly and patients with renal impairment
• Consult physician during pregnancy and lactation

Dosage

As directed by the Physician.