What is the treatment for cyclical vomiting syndrome (CVS)?

Treatment of Cyclical Vomiting Syndrome (CVS)

Cyclical vomiting syndrome (CVS) requires a phase-specific treatment approach targeting both episode prevention and acute symptom management, with tricyclic antidepressants being the first-line prophylactic therapy for moderate-severe cases. 1

Understanding CVS Phases and Classification

CVS has four distinct phases, each requiring specific management approaches:

• Inter-episodic phase: Period between episodes; focus on prophylaxis 2
• Prodromal phase: Early warning period before vomiting begins; ideal time for abortive therapy 2
• Emetic/vomiting phase: Active vomiting period; requires supportive care 2
• Recovery phase: Post-vomiting period; focus on rehydration and nutrition 2

Disease severity classification guides treatment intensity:

• Mild CVS: <4 episodes/year, each lasting <2 days, no ED visits 2, 1
• Moderate-severe CVS: ≥4 episodes/year, lasting >2 days, requiring ED visits 2, 1

Prophylactic Treatment (Inter-episodic Phase)

For moderate-severe CVS, prophylactic medications are essential:

• First-line therapy: Tricyclic antidepressants (TCAs) with 67-75% response rate 1

  • Amitriptyline for patients ≥5 years old 3
  • Cyproheptadine for children <5 years old 3
  • Careful titration to higher doses may be needed in refractory cases 3

• Second-line options:

  • Propranolol (beta-blocker) 3
  • Anticonvulsants (topiramate, zonisamide) 4, 3
  • NK1 receptor antagonists 3
  • Calcium channel blockers 3

• Psychiatric management: Treatment of underlying anxiety and depression can significantly reduce episode frequency 1

Abortive Treatment (Prodromal Phase)

Early intervention during the prodromal phase is crucial:

• First-line abortive therapy: Combination of sumatriptan and antiemetics 2

  • Sumatriptan: Nasal spray (administered in head-forward position) or subcutaneous injection 2
  • Ondansetron: Sublingual formulation preferred during active symptoms 2

• Additional abortive options:

  • Promethazine or prochlorperazine suppositories 2
  • Sedating agents: Diphenhydramine, benzodiazepines (alprazolam in sublingual or rectal form) 2
  • "Abortive cocktail" combining multiple agents often more effective than monotherapy 2

Management During Emetic Phase

For patients unable to abort episodes at home:

• Emergency department management:
  • IV dextrose-containing fluids (essential for all CVS patients) 2
  • IV antiemetics 2
  • Pain management: IV ketorolac as first-line analgesic 2
  • Sedation: IV benzodiazepines in a quiet, dark room 2
  • Sedating antipsychotics (droperidol, haloperidol) for refractory cases 2

Recovery Phase Management

• Focus on rehydration with electrolyte-rich fluids (sports drinks) 2
• Gradually introduce nutrient drinks as tolerated 2
• Most recovery phases last approximately 1-2 days 2

Common Pitfalls to Avoid

• Diagnostic delays: CVS is often misdiagnosed, leading to years of unnecessary testing and delayed treatment 1
• Missing the prodromal window: Failing to treat during the prodromal phase significantly reduces abortive therapy effectiveness 2, 1
• Inadequate sedation: Sedation is a treatment goal itself, not just symptom management 2
• Overlooking psychiatric comorbidities: 50-60% of CVS patients have mood disorders that require treatment 1
• Assuming hot water bathing is exclusive to cannabinoid hyperemesis: This symptom occurs in 48% of non-cannabis using CVS patients 1

Special Considerations

• Patients with refractory CVS may benefit from treatment guided by comorbidities and specific subphenotypes 3
• Some patients may develop "coalescent CVS" with progressively fewer symptom-free days 1
• A personal or family history of migraines supports CVS diagnosis and may guide treatment choices 2, 1