What is the treatment for Hyperemesis Cannabinoid Syndrome?

Treatment of Cannabinoid Hyperemesis Syndrome (CHS)

Complete cannabis cessation is the definitive treatment for CHS, with all other therapies serving as temporary symptomatic management until abstinence can be achieved. 1

Diagnosis and Clinical Features

Before initiating treatment, it's important to confirm the diagnosis of CHS based on these criteria:

1. Clinical features: Stereotypical episodic vomiting occurring ≥3 times annually
2. Cannabis use patterns: >1 year of cannabis use before symptom onset; frequency >4 times weekly
3. Cannabis cessation: Resolution of symptoms after abstinence for ≥6 months or at least equal to the duration of 3 typical vomiting cycles 1

Characteristic features include:

• Cyclic vomiting and abdominal pain
• Relief with hot showers/baths (reported in 71% of patients)
• Symptoms that resolve with cannabis cessation and recur with reinitiation

Treatment Algorithm

Acute Management (During Emetic Phase)

1. First-line medications:

   • Topical capsaicin (0.1%) applied to abdomen with monitoring for efficacy and adverse effects 1
   • Haloperidol or other antipsychotics (butyrophenones) have shown superior efficacy compared to conventional antiemetics 1, 2

2. Second-line medications:

   • Benzodiazepines for sedation and symptom control 1, 3
   • Olanzapine for refractory symptoms 1, 4
   • Promethazine for antiemetic effects 1
   • Ondansetron (though often less effective than other options) 1

3. Medications to avoid:

   • Opioids - worsen nausea and carry high addiction risk 1, 4

4. Supportive care:

   • Aggressive IV fluid hydration for dehydration and electrolyte abnormalities 5
   • Consider additional PONV (postoperative nausea and vomiting) prophylaxis in patients consuming >1.5g/day of smoked cannabis 1

Long-term Management

1. Cannabis cessation counseling - essential for complete resolution 1

2. Pharmacologic prophylaxis:

   • Tricyclic antidepressants (particularly amitriptyline)
     • Start at 25mg at bedtime
     • Titrate weekly to reach minimal effective dose (75-100mg) 1

3. Psychiatric co-management:

   • Consider referral to psychiatrist/psychologist for:
     • Patients with refractory symptoms
     • Those with extensive psychiatric comorbidity
     • Assistance with cannabis cessation 1

Important Clinical Considerations

• Diagnostic pitfall: CHS is often misdiagnosed, leading to unnecessary testing and inappropriate treatments. Consider CHS in any patient with cyclical vomiting and chronic cannabis use 4

• Treatment resistance: Conventional antiemetics (antihistamines, serotonin antagonists, dopamine antagonists) often have limited effectiveness 4

• Recidivism: Despite diagnosis and education, many patients remain uncertain about the role of cannabis in their symptoms and continue use, leading to high recurrence rates 1

• Differentiation from CVS: Cannabis use in Cyclic Vomiting Syndrome (CVS) is more occasional and often postdates symptom onset, whereas in CHS, heavy cannabis use precedes symptom onset by >1 year 1

• Emergency department approach: Requires immediate evaluation for life-threatening disorders (acute abdomen, bowel obstruction, mesenteric ischemia, pancreatitis, myocardial infarction) before confirming CHS diagnosis 1

The evidence for CHS treatment is limited to case series and small clinical trials, but the most recent guidelines emphasize cannabis cessation as the only definitive treatment, with symptomatic management serving as a bridge until abstinence can be achieved 1.