What is the usual management for Cyclic Vomiting Syndrome (CVS)?

Management of Cyclic Vomiting Syndrome

The American Gastroenterological Association recommends amitriptyline 25-150 mg nightly as first-line prophylaxis for moderate-severe CVS (≥4 episodes/year lasting >2 days), combined with sumatriptan 20 mg intranasal plus ondansetron 8 mg sublingual as abortive therapy during the prodromal phase. 1

Disease Severity Classification Determines Treatment Intensity

First, classify CVS severity to guide your therapeutic approach:

• Mild CVS: <4 episodes/year, each lasting <2 days, no ED visits or hospitalizations → requires only abortive therapy 1
• Moderate-severe CVS: ≥4 episodes/year, lasting >2 days, requiring ED visits or hospitalizations → requires both prophylactic AND abortive therapy 1, 2

Phase-Specific Management Approach

Inter-Episodic Phase: Prophylactic Therapy

First-line prophylaxis:

• Start amitriptyline 25 mg at bedtime, titrate to goal dose of 1-1.5 mg/kg (typically 75-150 mg nightly) 1
• Obtain baseline ECG before initiating due to QTc prolongation risk 1
• Response rate is 67-75% in clinical studies 1, 2

Second-line prophylactic options when amitriptyline fails or is not tolerated:

• Topiramate: start 25 mg daily, titrate to 100-150 mg daily in divided doses; monitor electrolytes and renal function twice yearly 1
• Levetiracetam: start 500 mg twice daily, titrate to 1000-2000 mg daily in divided doses; monitor CBC 1
• Zonisamide: start 100 mg daily, titrate to 200-400 mg daily; monitor electrolytes and renal function twice yearly 1

Adjunctive therapy:

• Aprepitant (neurokinin-1 antagonist): 80 mg 2-3 times weekly for adolescents 40-60 kg, or 125 mg 2-3 times weekly for adolescents >60 kg 1

Essential lifestyle modifications for all patients:

• Maintain regular sleep schedule 1
• Avoid prolonged fasting 1
• Identify and avoid individual triggers 1
• Implement stress management techniques 1

Prodromal Phase: Abortive Therapy

Timing is critical: The probability of successfully aborting an episode is highest when medications are taken immediately at onset of prodromal symptoms (impending sense of doom, panic, nausea) 1, 2

Standard abortive regimen:

• Sumatriptan 20 mg intranasal (can repeat once after 2 hours, maximum 2 doses per 24 hours) 1
• Administer in head-forward position to optimize medication contact with anterior nasal receptors 1
• Subcutaneous injection is an alternative route if intranasal not tolerated 1
• PLUS ondansetron 8 mg sublingual, can repeat every 4-6 hours during episode 1

Additional abortive agents to consider:

• Promethazine 12.5-25 mg oral/rectal every 4-6 hours 1
• Prochlorperazine 5-10 mg every 6-8 hours or 25 mg suppository every 12 hours 1
• Sedatives (alprazolam, lorazepam, diphenhydramine) to truncate the episode, though use caution in adolescents with substance abuse risk 1

Emetic Phase: Emergency Department Management

If home abortive therapy fails, immediate ED presentation for:

Aggressive IV fluid and electrolyte replacement:

• Use IV dextrose-containing fluids for rehydration and metabolic support 1, 2
• Check and correct electrolyte abnormalities immediately 2

Antiemetic therapy:

• Ondansetron 8 mg IV every 4-6 hours 1

Pain management:

• IV ketorolac as first-line non-narcotic analgesia for severe abdominal pain 1, 2

Sedation:

• IV benzodiazepines in a quiet, dark room to minimize sensory stimulation 1, 2

Refractory cases:

• Droperidol or haloperidol as dopamine antagonists 1, 2
• Multiple concurrent agents with different mechanisms of action may be necessary, administered around-the-clock rather than PRN 2

Recovery Phase

Focus on gradual reintroduction:

• Rehydration with electrolyte-rich fluids (sports drinks) 2
• Small, frequent sips as tolerated 2
• Gradual introduction of nutrient drinks 2

Critical Diagnostic Consideration Before Treatment

Screen all patients for cannabis use before confirming CVS diagnosis:

• Cannabis use >4 times weekly for >1 year suggests cannabinoid hyperemesis syndrome (CHS) rather than CVS 1, 2
• Hot water bathing is present in 48% of CVS patients who don't use cannabis, so this behavior alone does not distinguish CHS from CVS 2

Management of Comorbid Conditions

Screen for psychiatric comorbidities in all CVS patients:

• Anxiety, depression, and panic disorder are present in 50-60% of CVS patients 1, 2
• Treating underlying anxiety can decrease CVS episode frequency 2
• Consider cognitive-behavioral therapy for psychological triggers 2

Personal or family history of migraine:

• Present in 20-30% of CVS patients 1
• Supports CVS diagnosis and may guide treatment selection toward anti-migraine medications 1, 2

Common Pitfalls to Avoid

Missing the prodromal window dramatically drops abortive therapy effectiveness - educate patients to recognize prodromal symptoms (impending sense of doom, panic, inability to communicate) and take medications immediately 1, 2

Do not underestimate CVS severity - approximately one-third of adults with CVS become disabled 2

Do not misinterpret self-soothing behaviors (excessive water drinking, self-induced vomiting) as malingering - these are specific to CVS and provide temporary relief 2

Do not overlook retching and nausea - these symptoms are equally disabling as vomiting itself and require aggressive treatment 1, 2

Inadequate sedation can worsen symptoms - ensure appropriate sedation during acute episodes 2