Metoclopromide

# Metoclopromide ## Overview - **Classification**: Dopamine receptor antagonist, Prokinetic agent. - **Mechanism**: Blocks D2 dopamine receptors in the chemoreceptor trigger zone (CTZ) reducing nausea/vomiting. Increases acetylcholine release in the GI tract, enhancing motility. ## Primary Indications 1. **Diabetic Gastroparesis** - Symptomatic relief of acute and recurrent diabetic gastroparesis. 2. **Gastroesophageal Reflux Disease (GERD)** - Short-term symptomatic relief of GERD unresponsive to conventional therapy. 3. **Prevention of Nausea/Vomiting** - Prevention of chemotherapy-induced (CINV) and post-operative (PONV) nausea and vomiting. ## Adult Dosing ### Standard Dosing **Diabetic Gastroparesis** - **Dose**: **10 mg** - **Frequency**: Four times daily (30 minutes before meals and at bedtime) - **Route**: PO - **Duration**: **2 to 8 weeks** (limit due to TD risk) - **Max Dose**: **10 mg/dose** **Symptomatic GERD (Short-term)** - **Dose**: **10-15 mg** - **Frequency**: Four times daily (30 minutes before meals and at bedtime) - **Route**: PO - **Duration**: **4 to 12 weeks** (limit due to TD risk) - **Max Dose**: **10 mg/dose** for chronic use **Prevention of Post-Operative Nausea/Vomiting (PONV)** - **Dose**: **10-20 mg** - **Frequency**: Single dose - **Route**: IV or IM (at end of surgical procedure) - **Max Dose**: **20 mg/dose** **Prevention of Chemotherapy-Induced Nausea/Vomiting (CINV)** - **Dose**: **1-2 mg/kg** - **Frequency**: 30 minutes before chemotherapy, then Q2-4H for 2-5 doses - **Route**: IV (slow infusion over at least 15 minutes) - **Max Dose**: **2 mg/kg/dose** ### Dose Adjustments - **Renal Impairment**: CrCl < 40 mL/min, reduce dose by **50%**. - **Hepatic Impairment**: No specific adjustment, but monitor for increased adverse effects. - **Elderly Patients**: Start with lower doses (e.g., **5 mg** PO QID). Increased risk of CNS effects and tardive dyskinesia (TD). ## Pediatric Dosing **Note**: Due to potential for serious adverse effects like tardive dyskinesia and extrapyramidal symptoms (EPS), metoclopramide is generally avoided in pediatric patients unless other options are ineffective or contraindicated. Limit duration to **5 days or less** for acute N/V. ### Neonates (0-28 days) - **Dose**: **0.05-0.1 mg/kg/dose** - **Frequency**: Q6-8H - **Maximum**: **0.1 mg/kg/dose** - **Special Notes**: Higher risk of EPS and CNS depression. Use with extreme caution. Avoid long-term use. ### Infants (1-12 months) - **Dose**: **0.1 mg/kg/dose** - **Frequency**: Q6-8H - **Maximum**: **0.1 mg/kg/dose** - **Special Notes**: Risk of EPS. Limit duration to 5 days for acute N/V. ### Children (1-12 years) - **Dose**: **0.1 mg/kg/dose** - **Frequency**: Q6-8H - **Maximum**: **10 mg/dose**. Total daily maximum **0.5 mg/kg/day** (up to 40 mg/day). - **Special Notes**: Risk of EPS. Limit duration to 5 days for acute N/V. ### Adolescents (13-18 years) - **Dose**: Adult dosing may be used. - **Maximum**: **10 mg/dose** for chronic use, **20 mg/dose** for acute N/V. - **Special Notes**: Limit duration to **12 weeks** for chronic use due to TD risk. ## Safety Information ### Contraindications - **Absolute**: GI hemorrhage, obstruction, or perforation. - **Absolute**: Pheochromocytoma (risk of hypertensive crisis). - **Absolute**: History of tardive dyskinesia (TD) from metoclopramide or neuroleptics. - **Absolute**: Epilepsy or other conditions increasing seizure threshold. - **Absolute**: Concomitant use with other drugs likely to cause EPS (e.g., antipsychotics). - **Relative**: Parkinson's disease (may exacerbate symptoms). ### Common Adverse Effects - **Very Common (>10%)**: Somnolence, asthenia. - **Common (1-10%)**: Restlessness, fatigue, headache, dizziness, diarrhea, nausea. - **Serious but Rare**: **Tardive dyskinesia (TD)** (often irreversible, limit duration), **Neuroleptic Malignant Syndrome (NMS)**, **Extrapyramidal Symptoms (EPS)** (acute dystonia, parkinsonism, akathisia), depression with suicidal ideation. ### Key Drug Interactions - **Dopaminergic drugs (levodopa, bromocriptine)**: Antagonizes effects; avoid concomitant use. - **Anticholinergics/Opioids**: Antagonize GI prokinetic effects; avoid if prokinetic effect desired. - **CNS Depressants (alcohol, benzodiazepines)**: Additive CNS depression; caution advised. - **SSRIs, TCAs**: Increased risk of serotonin syndrome; monitor closely. ## Monitoring & Follow-up - **Before Treatment**: Assess for history of GI obstruction, epilepsy, Parkinson's, pheochromocytoma, or prior TD. - **During Treatment**: Monitor closely for EPS (involuntary movements, rigidity) especially within **24-48 hours** of initiation or dose increase. - **During Treatment**: Monitor for signs of TD (facial grimacing, tongue protrusion) with chronic use. - **Clinical Signs**: Patient should report any involuntary movements, fever, severe muscle rigidity, or altered mental status immediately. ## Clinical Pearls - 💡 **Duration Limit**: Due to risk of **tardive dyskinesia (TD)**, limit chronic use (e.g., gastroparesis, GERD) to **12 weeks**. - 💡 **Administration Timing**: For prokinetic effect, administer oral doses **30 minutes before meals and at bedtime**. IV infusions should be given slowly (over 15 minutes) to reduce dystonic reaction risk. - 💡 **EPS Management**: Acute dystonic reactions can often be managed with IV **diphenhydramine** or **benztropine**. > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.