What are the treatment orders for cyclic vomiting syndrome?

Treatment Orders for Cyclic Vomiting Syndrome

For moderate-severe CVS (≥4 episodes/year lasting >2 days), initiate both prophylactic therapy with amitriptyline 25 mg at bedtime (titrate to 1-1.5 mg/kg nightly) and provide abortive therapy with sumatriptan 20 mg intranasal plus ondansetron 8 mg sublingual for use at prodromal symptom onset. 1, 2

Disease Severity Classification

First, classify CVS severity to determine treatment intensity 1, 3:

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

Critical Initial Screening

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, 3. Cannabis cessation for 6 months or at least 3 typical cycle lengths is required to retrospectively diagnose CHS 2. Note that hot water bathing occurs in 48% of CVS patients who don't use cannabis, so this behavior alone does not distinguish CHS from CVS 3.

Screen for anxiety, depression, and panic disorder, as psychiatric comorbidities are present in 50-60% of CVS patients 1, 2, 3. Treating underlying anxiety can decrease CVS episode frequency 1, 2.

Prophylactic Therapy Orders (Inter-Episodic Phase)

First-Line: Amitriptyline

• Start: 25 mg PO at bedtime 1, 2
• Titrate: Up to goal dose of 1-1.5 mg/kg at bedtime (typically 75-150 mg nightly) 1, 2
• Response rate: 67-75% 1, 2, 3
• Monitoring: Obtain baseline ECG before initiating due to QTc prolongation risk 1, 2

Second-Line Options (if amitriptyline fails or not tolerated):

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

Adjunctive Prophylactic Therapy:

• Aprepitant (NK1 antagonist): 80 mg PO 2-3 times weekly for adolescents 40-60 kg; 125 mg PO 2-3 times weekly for adolescents >60 kg 1

Abortive Therapy Orders (Prodromal Phase)

Patient education is critical: The probability of successfully aborting an episode is highest when medications are taken immediately at the onset of prodromal symptoms 1, 2, 3. Educate patients to recognize stereotypical prodromal symptoms including impending sense of doom, panic, fatigue, mental fog, restlessness, anxiety, headache, bowel urgency, diaphoresis, or flushing 1, 3.

Standard Abortive Regimen (nearly all patients require combination therapy, not monotherapy):

• Sumatriptan: 20 mg intranasal spray (head-forward position to optimize anterior nasal receptor contact); may repeat once after 2 hours, maximum 2 doses per 24 hours 1, 2. Subcutaneous injection is an alternative route if intranasal not tolerated 1
• Ondansetron: 8 mg sublingual tablet every 4-6 hours during the episode 1, 2

Additional Abortive Agents:

• Promethazine: 12.5-25 mg PO/rectal every 4-6 hours 1, 2
• Prochlorperazine: 5-10 mg PO every 6-8 hours OR 25 mg suppository every 12 hours 1, 2
• Alprazolam: Sublingual or rectal formulation (use caution in adolescents with substance abuse risk) 1, 3
• Diphenhydramine: For sedation to truncate episode 1, 3

Emergency Department/Acute Episode Management Orders (Emetic Phase)

If home abortive therapy fails, order the following for ED presentation 1, 3:

Immediate Interventions:

• Place patient in quiet, dark room to minimize sensory stimulation 3
• Check and correct electrolyte abnormalities immediately 3

IV Fluid Resuscitation:

• 10% dextrose-containing IV fluids for aggressive rehydration and metabolic support 1, 2, 3
• Electrolyte replacement as needed 1, 2

Antiemetic Therapy:

• Ondansetron: 8 mg IV every 4-6 hours 1, 2

Analgesia:

• Ketorolac: IV as first-line non-narcotic analgesia for severe abdominal pain 1, 3

Sedation:

• Benzodiazepines: IV in quiet, dark room 1, 3

Refractory Cases:

• Droperidol OR Haloperidol: For cases not responding to initial therapy 1, 3. Multiple concurrent agents with different mechanisms of action may be necessary, administered around-the-clock rather than PRN 3

Recovery Phase Management Orders

• Rehydration: Electrolyte-rich fluids (sports drinks) with small, frequent sips as tolerated 1, 3
• Gradual introduction: Nutrient drinks as tolerated 1, 3

Essential Lifestyle Modification Orders (All Patients)

Regardless of disease severity, order the following non-pharmacological interventions 1, 2:

• Maintain regular sleep schedule; avoid sleep deprivation 1, 2
• Avoid prolonged fasting 1, 2
• Identify and avoid individual triggers 1, 2
• Implement stress management techniques 1, 2

Psychiatric Referral Orders

• Refer to psychiatry or psychology for cognitive behavioral therapy or mindfulness meditation, especially given 50-60% prevalence of psychiatric comorbidities 2

Common Pitfalls to Avoid

• Missing the prodromal window dramatically reduces abortive therapy effectiveness - emphasize immediate medication administration at first prodromal symptom 1, 2, 3
• Inadequate sedation can worsen symptoms during acute episodes 1, 3
• Overlooking retching and nausea - these symptoms are equally disabling as vomiting itself and require aggressive treatment 1, 3
• Misinterpreting self-soothing behaviors (excessive water drinking, self-induced vomiting) as malingering - these are specific to CVS and provide temporary relief 3
• Underestimating CVS severity - approximately one-third of adults with CVS become disabled 3