What is the recommended treatment for vomiting?

Treatment of Vomiting

For general vomiting, dopamine receptor antagonists such as metoclopramide (10-20 mg PO/IV every 6-8 hours) are recommended as first-line treatment, with 5-HT3 receptor antagonists like ondansetron reserved for chemotherapy-induced or refractory vomiting. 1

First-Line Pharmacologic Treatment Options

Dopamine Antagonists

• Metoclopramide (10-20 mg PO/IV every 6-8 hours): Particularly effective for gastroparesis or opioid-induced nausea and vomiting 1
• Prochlorperazine (5-10 mg PO/IV every 6-8 hours): Effective for severe nausea and vomiting 1
• Haloperidol (0.5-2 mg PO/IV every 4-6 hours): Particularly effective for opioid-induced nausea 1

5-HT3 Receptor Antagonists

• Ondansetron (8 mg PO/IV every 8-12 hours): Highly effective for chemotherapy-induced nausea and vomiting 2
• Granisetron (1 mg PO twice daily or 1 mg IV daily): Alternative to ondansetron with similar efficacy 1
• Palonosetron (0.25 mg IV single dose): Longer half-life (40 hours), superior for delayed nausea and vomiting 1

Other Options

• Dexamethasone (4-20 mg IV/PO daily): Particularly effective when combined with other antiemetics 1
• Diphenhydramine (25-50 mg PO/IV every 6 hours): Useful when sedation is desired or for managing extrapyramidal symptoms from other antiemetics 1

Treatment Algorithm Based on Cause of Vomiting

Chemotherapy-Induced Nausea and Vomiting

1. High emetogenic potential: 3-drug combination of NK1 receptor antagonist, 5-HT3 receptor antagonist, and dexamethasone 3
2. Moderate emetogenic potential: 5-HT3 receptor antagonist plus dexamethasone 3
3. Low emetogenic potential: Single dose of 5-HT3 receptor antagonist or dexamethasone 3
4. Minimal emetogenic potential: No routine prophylaxis needed 3

Breakthrough Vomiting

1. Re-evaluate emetic risk, disease status, concurrent illnesses, and medications 3
2. Add agent from different drug class than what patient is already receiving 3
3. Consider around-the-clock administration rather than PRN dosing 3
4. Use IV or rectal route if oral route not feasible due to ongoing vomiting 3
5. Ensure adequate hydration and correct electrolyte abnormalities 3

Refractory Vomiting

1. Combine medications from different classes (e.g., dopamine antagonist + dexamethasone) 1
2. Add olanzapine if not previously included in regimen 3
3. Consider cannabinoids (dronabinol, nabilone) for chemotherapy-induced nausea and vomiting refractory to standard therapies 3
4. Consider opioid rotation if applicable 3

Special Considerations

Non-Pharmacologic Management

• Fluid and electrolyte replacement: Critical for preventing dehydration, especially in severe vomiting 4
• Small, frequent meals: Helps reduce gastric distension 4
• Avoidance of trigger foods: Individualize based on patient-specific triggers 4

Radiation-Induced Nausea and Vomiting

• Upper abdominal radiation: Oral ondansetron (8 mg, 2-3 times daily) with or without dexamethasone 3
• Total body irradiation: Ondansetron (8 mg, 2-3 times daily) or granisetron with or without dexamethasone 3

Anticipatory Nausea and Vomiting

• Best approach: Optimal control of acute and delayed emesis 3
• Behavioral therapies: Progressive muscle relaxation, systematic desensitization, or hypnosis 3
• Benzodiazepines: May help reduce anticipatory symptoms 3

Monitoring and Side Effects

• Monitor for extrapyramidal symptoms with dopamine antagonists and have diphenhydramine available for treatment 1
• Monitor for QT prolongation with certain antiemetics, especially in patients with cardiac issues 1
• Reassess antiemetic efficacy within 30-60 minutes of administration 1

Common Pitfalls to Avoid

1. Treating symptoms without addressing underlying cause: Always consider non-chemotherapy causes of vomiting such as brain metastases, electrolyte abnormalities, or bowel obstruction 3
2. Using PRN dosing: Around-the-clock administration is more effective for preventing vomiting 3
3. Relying on oral medications during active vomiting: Use IV or rectal routes instead 3
4. Monotherapy for severe vomiting: Combination therapy targeting different pathways is often more effective 1
5. Ignoring hydration status: Ensure adequate hydration and electrolyte balance 3

Remember that prevention of vomiting is generally more effective than treating established symptoms. When possible, administer antiemetics prophylactically before the onset of vomiting, particularly in high-risk situations.