What is the recommended treatment for nausea?

Treatment of Nausea

For the treatment of nausea, 5-HT3 receptor antagonists such as ondansetron (4-8 mg IV/PO) are recommended as first-line therapy due to their superior efficacy and safety profile. 1, 2

First-Line Antiemetic Options

• 5-HT3 receptor antagonists:

  • Ondansetron: 4-8 mg IV/PO every 6 hours 1, 2
  • Granisetron: 1-2 mg PO daily or 1 mg PO twice daily 1
  • Palonosetron: 0.25 mg IV (for chemotherapy-induced nausea) 1

• Dopamine antagonists:

  • Metoclopramide: 10-20 mg PO/IV every 4-6 hours 1, 3
  • Prochlorperazine: 10 mg PO/IV every 6 hours or 25 mg suppository PR every 12 hours 1
  • Haloperidol: 0.5-2 mg PO/IV every 4-6 hours 1

Second-Line and Adjunctive Therapies

• Corticosteroids: Dexamethasone 4-12 mg IV/PO daily (particularly effective when combined with 5-HT3 antagonists) 1

• Benzodiazepines: Lorazepam 0.5-2 mg PO/SL/IV every 6 hours (especially helpful for anticipatory nausea or anxiety-related nausea) 1

• Antihistamines: Second-generation agents like loratadine (10 mg) or cetirizine (10 mg) for nausea with urticaria 1

• Atypical antipsychotics: Olanzapine 5-10 mg PO daily (category 1 evidence for breakthrough chemotherapy-induced nausea) 1

Treatment Algorithm Based on Nausea Etiology

For Chemotherapy-Induced Nausea

1. High emetogenic risk chemotherapy: Combination therapy with 5-HT3 antagonist + dexamethasone + NK1 receptor antagonist 1

2. Moderate emetogenic risk: 5-HT3 antagonist + dexamethasone 1

3. Breakthrough nausea: Add one agent from a different drug class (olanzapine 5-10 mg PO is category 1) 1

For Post-Operative Nausea

• Single-dose ondansetron 4 mg IV has shown optimal efficacy 4, 5
• Number needed to treat is approximately 4 patients to prevent one case of post-operative nausea and vomiting 5, 6

For General Nausea

• Start with a 5-HT3 antagonist (ondansetron 4-8 mg) 2, 7
• If inadequate response, add a dopamine antagonist (metoclopramide or prochlorperazine) 1, 3
• For persistent symptoms, consider scheduled rather than as-needed administration 1, 3

Special Considerations

• For persistent nausea, switch from as-needed to scheduled administration of antiemetics for at least one week 1, 3

• Always assess for other causes of nausea such as constipation, CNS pathology, electrolyte disturbances, or medication interactions 1, 3

• Ensure adequate hydration, as dehydration can worsen nausea symptoms 1, 3

• For patients with hepatic impairment, ondansetron dosage adjustment may be necessary as clearance is reduced 2-3 fold in severe impairment 2

Common Pitfalls

• First-generation antihistamines (like diphenhydramine) should be avoided as they can potentially worsen hypotension and convert minor reactions into hemodynamically significant events 1

• Avoid using only one class of antiemetics for persistent nausea; multimodal therapy targeting different pathways is more effective 1, 3

• Oral administration may not be feasible during active vomiting; consider alternative routes (IV, suppository) 1

• Monitor for potential side effects of 5-HT3 antagonists, including headache (NNH=36) and elevated liver enzymes (NNH=31) 6