What are the best medications for treating nausea in the Emergency Department (ED)?

Best Medications for Nausea in the Emergency Department

First-line medications for nausea in the ED should be dopaminergic antagonists such as haloperidol, risperidone, metoclopramide, or prochlorperazine, with ondansetron added as a second agent for refractory cases. 1

First-Line Antiemetic Agents

Dopaminergic Antagonists

• Medications that target dopaminergic pathways are recommended as first-line agents for nausea and vomiting in the ED 1
• Specific options include:
  • Haloperidol: 0.5-2 mg IV/SC/PO every 3-6 hours 1
  • Prochlorperazine: 5-10 mg IV/PO every 3-4 hours 1
  • Metoclopramide: 10 mg IV (administered slowly to reduce risk of akathisia) 2
  • Chlorpromazine: 12.5-25 mg IV or 25-50 mg PO every 3-4 hours 1

Considerations for First-Line Agents

• Droperidol has shown superior efficacy compared to other antiemetics in some studies but has an FDA black box warning for QT prolongation, limiting its use to refractory cases 2
• Prochlorperazine and metoclopramide require monitoring for akathisia, which can develop within 48 hours of administration 2
• Promethazine causes more sedation than other agents but may be suitable when sedation is desirable 2

Second-Line and Adjunctive Agents

5-HT3 Antagonists

• Ondansetron (4 mg IV) should be added as a second agent when first-line medications are unable to control symptoms 1
• Ondansetron has been shown to be effective for postoperative nausea and vomiting in both adults and children 3
• Ondansetron is as effective as promethazine but without the sedation or akathisia side effects 2

Other Adjunctive Agents

• Dexamethasone: 2-8 mg IV/PO every 3-6 hours, particularly useful for bowel obstruction or intracranial hypertension 1
• Scopolamine: 1.5-3 mg topical patch every 72 hours for increased oral secretions 1
• Lorazepam: 0.5-2 mcg IV/PO every 6 hours for anticipatory nausea 1

Special Clinical Scenarios

Cyclic Vomiting Syndrome in the ED

• Sumatriptan combined with an antiemetic agent (like ondansetron) is recommended 1
• Sedation is an effective strategy, using:
  • Promethazine (which has both antiemetic and sedating properties)
  • Diphenhydramine
  • Benzodiazepines (alprazolam available in sublingual form)
  • In severe cases, sedating antipsychotics like droperidol or haloperidol 1

Chemotherapy-Induced Nausea and Vomiting

• For highly emetogenic chemotherapy, a 4-drug regimen is recommended:
  • Olanzapine (10 mg daily for 3 days)
  • NK1 receptor antagonist (aprepitant or fosaprepitant)
  • 5-HT3 antagonist
  • Dexamethasone 1

Route of Administration Considerations

• For actively vomiting patients, consider alternative routes:
  • Ondansetron is available as sublingual tablets 1
  • Promethazine and prochlorperazine are available as rectal suppositories 1
  • Sumatriptan can be administered via nasal spray in a head-forward position 1

Evidence Quality and Limitations

• Studies have shown significant placebo effect in treating nausea in the ED, suggesting that supportive care including IV fluids may be sufficient for many patients 4, 5, 6
• A Cochrane review found no definitive evidence supporting superiority of any antiemetic over placebo or other antiemetics in the ED setting 4
• Recent randomized controlled trials have not demonstrated statistically significant superiority of ondansetron or metoclopramide over placebo for undifferentiated ED nausea 5

Practical Algorithm for ED Nausea Management

1. Start with a dopaminergic antagonist (haloperidol, prochlorperazine, or metoclopramide) 1
2. Provide IV hydration concurrently 4
3. If inadequate response, add ondansetron 4 mg IV 1, 3
4. Consider route of administration based on severity of vomiting (IV, sublingual, rectal) 1
5. For severe, refractory cases, consider sedation strategy with benzodiazepines or droperidol 1, 2

Cautions and Monitoring

• Monitor for QT prolongation with droperidol 2
• Watch for akathisia with prochlorperazine and metoclopramide; can be treated with diphenhydramine 2
• Reduce infusion rate of metoclopramide to decrease risk of akathisia 2
• Use caution with olanzapine in elderly patients due to risks of sedation and metabolic effects 1