What is the composition of the abortive cocktail for cyclic vomiting syndrome?

The Abortive Cocktail for Cyclic Vomiting Syndrome

The abortive cocktail for cyclic vomiting syndrome typically consists of a combination of sumatriptan, an antiemetic such as ondansetron, and a sedating agent such as diphenhydramine or a benzodiazepine like alprazolam. 1

Components of the Abortive Cocktail

The standard components include:

1. Triptans

   • Sumatriptan: 20 mg intranasally or 6 mg subcutaneously
   • Can be repeated once after 2 hours if needed (maximum 2 doses in 24 hours)
   • Particularly effective when administered early in the prodromal phase

2. Antiemetics

   • Ondansetron: 8 mg sublingual every 4-6 hours during episode
   • Alternative options:
     • Promethazine: 12.5-25 mg orally or rectally every 4-6 hours
     • Prochlorperazine: 5-10 mg every 6-8 hours or 25 mg suppository every 12 hours

3. Sedatives

   • Alprazolam: 0.5-2 mg every 4-6 hours (available in sublingual and rectal forms)
   • Lorazepam: Similar dosing to alprazolam
   • Diphenhydramine: 12.5-25 mg every 4-6 hours

Administration Considerations

• For patients actively vomiting:
  • Sumatriptan can be given via nasal spray (administered in head-forward position to optimize contact with anterior nasal receptors) or subcutaneous injection
  • Ondansetron is available in sublingual form
  • Promethazine and prochlorperazine are available as rectal suppositories
  • Alprazolam is available in sublingual and rectal forms

Clinical Pearls and Pitfalls

• Timing is crucial: The cocktail is most effective when administered early in the prodromal phase 1, 2
• Combination therapy: While some patients respond to monotherapy, most require at least 2 agents to reliably abort attacks 1
• Sedation strategy: Inducing sedation is often an effective abortive approach in itself 1
• Route of administration: Consider non-oral routes when patients are actively vomiting 1
• Contraindications to watch for:
  • Sumatriptan: Avoid in pregnancy, ischemic heart disease, stroke, peripheral vascular disease, or uncontrolled hypertension
  • Ondansetron: Monitor for QTc prolongation (baseline ECG advised)
  • Benzodiazepines: Use with caution in pregnancy and those with history of substance abuse

When Home Management Fails

If the abortive cocktail fails to control symptoms at home, patients should proceed to the emergency department for:

• IV fluids (dextrose-containing)
• IV antiemetics
• IV benzodiazepines for sedation
• IV ketorolac for pain (preferred over opioids)
• Placement in a quiet, darker room 1

Special Considerations

• For patients with frequent, severe episodes (>4 episodes per year, each lasting >2 days), prophylactic therapy should be considered alongside the abortive cocktail 1
• The abortive cocktail should be part of a comprehensive treatment plan that includes trigger avoidance and management of comorbid conditions 1, 3
• In pediatric patients, similar components are used but with age-appropriate dosing 4

The abortive cocktail represents a targeted approach to rapidly terminate CVS episodes and minimize morbidity associated with prolonged vomiting episodes, dehydration, and electrolyte disturbances.