What is the treatment for cannabis-induced hyperemesis?

Treatment of Cannabis-Induced Hyperemesis Syndrome (CHS)

The definitive treatment for cannabis hyperemesis syndrome is complete cessation of cannabis use, which is the only intervention that leads to long-term resolution of symptoms. 1

Acute Management

• First-line pharmacological treatments:

  • Topical capsaicin (0.1%) applied to the abdomen provides symptom relief by activating transient receptor potential vanilloid type 1 receptors 2, 1
  • Antipsychotics are more effective than traditional antiemetics:
    • Haloperidol (0.05-0.1 mg/kg IV) has demonstrated superior efficacy compared to ondansetron 3, 1
    • Other effective antipsychotics include promethazine and olanzapine 2, 1

• Non-pharmacological intervention:

  • Hot showers or baths (hydrothermotherapy) provide temporary symptomatic relief and can be both therapeutic and a diagnostic clue 1, 4

• Treatments to avoid:

  • Opioids should be avoided as they may worsen nausea and carry addiction risk 2, 1
  • Traditional antiemetics like ondansetron often have limited efficacy compared to antipsychotics 3, 1

Emergency Department Approach

• Rule out life-threatening conditions first (acute abdomen, bowel obstruction, mesenteric ischemia, pancreatitis, myocardial infarction) 2

• Consider CHS in patients with:

  • Regular cannabis use (especially >4 times weekly for >1 year) 1
  • Cyclic vomiting episodes (≥3 episodes annually) 1
  • Relief with hot showers/baths 4, 5

• Treatment algorithm for acute CHS in ED:

  1. Topical capsaicin 0.1% to abdomen 2, 1
  2. Haloperidol IV (0.05-0.1 mg/kg) or other antipsychotic 3, 6
  3. Benzodiazepines may be considered for refractory cases 5
  4. Monitor for acute dystonia with haloperidol, especially at higher doses 3

Long-term Management

• Cannabis cessation counseling is essential and the only definitive treatment 1, 7

• Pharmacological support:

  • Tricyclic antidepressants (particularly amitriptyline) are the mainstay of therapy 2, 1
  • Start amitriptyline at 25 mg at bedtime and titrate weekly to reach minimal effective dose of 75-100 mg 2
  • Topical capsaicin (0.1%) cream can be used for maintenance therapy with monitoring for efficacy and adverse effects 2

• Supportive care:

  • Psychological support for anxiety and depression which are common comorbidities 1
  • Consider co-management with psychiatry for patients with extensive psychiatric comorbidity or treatment resistance 1

Diagnostic Considerations

• CHS should be diagnosed based on:
  • Stereotypical episodic vomiting (≥3 episodes annually) 2, 1
  • Cannabis use patterns: >1 year of use before symptom onset, frequency >4 times weekly 2, 1
  • Resolution of symptoms after abstinence for at least 6 months or duration equal to 3 typical vomiting cycles 2, 1

Common Pitfalls and Caveats

• CHS is frequently misdiagnosed, leading to unnecessary testing and ineffective treatments 5
• Patients often believe cannabis helps their symptoms (paradoxical effect) and may be reluctant to accept cannabis as the cause 2, 5
• Conventional antiemetics like ondansetron should not be considered first-line therapy as they often fail to provide relief 7, 3
• Monitor for acute dystonia with haloperidol, particularly at higher doses 3