Overview
Metoclopramide is a dopamine antagonist and prokinetic agent used to treat diabetic gastroparesis by enhancing gastric emptying and reducing symptoms like nausea and vomiting. It works primarily by increasing lower esophageal sphincter tone and accelerating gastric emptying through cholinergic stimulation in the gut.
Mechanism of Action
Metoclopramide acts as a dopamine D2 receptor antagonist in the gastrointestinal tract and chemoreceptor trigger zone, which increases acetylcholine release and enhances gastric motility and emptying. It also has antiemetic effects through central dopamine blockade.
Indications
- Relief of symptoms in adults with acute and recurrent diabetic gastroparesis
Common Doses
- 15 mg per spray (nasal spray)
Dosage
Administer one spray in one nostril per dose. Prime the pump with 10 sprays before first use. Do not repeat if dose uncertainty occurs; take next scheduled dose. Discard bottle 4 weeks after opening.
Contraindications
- History of tardive dyskinesia or dystonic reaction to metoclopramide
- Gastrointestinal hemorrhage, obstruction, or perforation
- Pheochromocytoma or catecholamine-releasing paragangliomas
- Epilepsy
- Hypersensitivity to metoclopramide
Side Effects
- Tardive dyskinesia
- Extrapyramidal reactions
- Neuroleptic malignant syndrome
- Drowsiness
- Restlessness
- Diarrhea
- Hyperprolactinemia
- Methemoglobinemia (in neonates)
Interactions
- Strong CYP2D6 inhibitors increase metoclopramide exposure
- Alcohol and CNS depressants enhance sedation
- Drugs that prolong QT interval may have additive effects
Counseling Points
- Use exactly as prescribed; do not exceed recommended dose
- Prime pump before first use
- Discard bottle 4 weeks after opening
- Report any involuntary movements or mood changes immediately
- Avoid alcohol and other CNS depressants
- Do not use if pregnant or breastfeeding without medical advice