What is the treatment for persistent vomiting?

Treatment of Persistent Vomiting

For persistent vomiting, the first-line treatment is dopamine receptor antagonists (such as prochlorperazine, haloperidol, or metoclopramide) titrated to maximum benefit and tolerance. 1

Initial Assessment and Management

• Identify and treat underlying causes when possible:

  • Chemotherapy/radiation-induced vomiting 1
  • Severe constipation or fecal impaction 1
  • Gastroparesis (treat with metoclopramide 10-20 mg every 6 hours) 1
  • Bowel obstruction 1
  • Medication-induced (check blood levels of digoxin, phenytoin, carbamazepine, tricyclic antidepressants) 1
  • Metabolic abnormalities (hypercalcemia, dehydration) 1

• For gastritis or gastroesophageal reflux:

  • Use proton pump inhibitors or H2 receptor antagonists 1

Stepwise Treatment Algorithm for Persistent Vomiting

1. First-line therapy: Initiate dopamine receptor antagonists 1

   • Prochlorperazine, haloperidol, or metoclopramide
   • Titrate to maximum benefit and tolerance
   • Consider around-the-clock dosing for optimal benefit 1

2. If vomiting persists, add one or more of the following: 1

   • 5-HT3 receptor antagonists (ondansetron, granisetron)
   • Anticholinergic agents (scopolamine)
   • Antihistamines (meclizine)
   • Cannabinoids (dronabinol, nabilone)

3. For refractory symptoms, consider adding: 1

   • Corticosteroids (dexamethasone 4-8 mg three to four times daily)
   • Continuous intravenous or subcutaneous infusion of antiemetics
   • Olanzapine (particularly helpful for patients with bowel obstruction) 1

4. For opioid-induced nausea: 1

   • Consider opioid rotation
   • Add non-nauseating co-analgesics
   • Consider anesthesiologic/neurosurgical procedures to reduce opioid requirements

Special Considerations

• For anxiety-related nausea: Add benzodiazepines (lorazepam) 1, 2

• For pregnancy-related vomiting: 1

  • Begin with diet and lifestyle modifications (small, frequent, bland meals)
  • First-line pharmacologic therapy: ginger (250 mg four times daily) and vitamin B6 (10-25 mg every 8 hours)
  • For persistent symptoms: H1-receptor antagonists (doxylamine, promethazine, dimenhydrinate)

• For children with persistent vomiting: 3, 4

  • Ondansetron (0.2 mg/kg oral; 0.15 mg/kg parenteral; maximum 4 mg)
  • Ensure adequate hydration (oral rehydration therapy for mild-moderate dehydration)

Important Pitfalls to Avoid

• Don't use antiemetics in patients with suspected mechanical bowel obstruction 1

• For chemotherapy-induced nausea and vomiting, follow specific antiemesis guidelines rather than general approaches 1

• Avoid long-term use of benzodiazepines due to risk of dependence 2

• Monitor for extrapyramidal side effects with dopamine receptor antagonists 2

• When using combination therapy, target different mechanisms of action for synergistic effect rather than replacing one antiemetic with another 1

• For severe, intractable vomiting that fails to respond to intensified palliative care efforts, consider palliative sedation as a last resort 1