How to manage cannabinoid hyperemesis syndrome?

Management of Cannabinoid Hyperemesis Syndrome

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

Acute Management in the Emergency Department

Initial Assessment

• First exclude life-threatening conditions including acute abdomen, bowel obstruction, mesenteric ischemia, pancreatitis, and myocardial infarction before attributing symptoms to CHS 2
• Check renal function and creatine kinase levels, as acute kidney injury and rhabdomyolysis can complicate severe vomiting episodes 3
• Provide aggressive intravenous fluid resuscitation to prevent dehydration-related complications 3

Pharmacologic Treatment for Acute Episodes

First-line acute therapies:

• Topical capsaicin (0.1%) cream applied to the abdomen provides symptom relief by activating transient receptor potential vanilloid type 1 receptors 2, 1
• Haloperidol is effective as a dopamine antagonist for acute symptom control 2, 1, 4
• Droperidol can be used as an alternative dopamine antagonist 4
• Promethazine and olanzapine are additional antipsychotic options that have shown efficacy 2, 1

Second-line options:

• Ondansetron may be tried but often has limited efficacy compared to its use in other conditions 1
• Metoclopramide can be considered but is less effective than dopamine antagonists 4
• Benzodiazepines (such as lorazepam) have shown benefit in case series by decreasing CB1 receptor activation in the frontal cortex and reducing anticipatory nausea 2, 5

Avoid entirely:

• Do not use opioids as they worsen nausea, fail to address the underlying pathophysiology, and carry high addiction risk 2, 1, 3, 4

Non-Pharmacologic Acute Management

• Hot showers or baths provide temporary symptomatic relief and serve as a diagnostic clue (reported in 71% of CHS patients) 2, 1

Long-Term Management Strategy

Cannabis Cessation (Essential)

• Cannabis cessation counseling is mandatory and represents the only definitive cure 2, 1
• Symptoms should resolve after abstinence for at least 6 months or duration equal to 3 typical vomiting cycles 2, 1
• Combining evidence-based psychosocial interventions with pharmacology may be necessary for successful long-term management 2

Prophylactic Pharmacotherapy

Tricyclic antidepressants are the mainstay of long-term therapy:

• Start amitriptyline at 25 mg at bedtime 2, 1
• Titrate weekly by 25 mg increments 2, 1
• Target minimal effective dose of 75-100 mg at bedtime 2, 1
• Monitor closely for efficacy and adverse effects 2

Supportive Care

• Provide psychological support as anxiety and depression are common comorbidities 1
• Consider co-management with psychiatry for patients with extensive psychiatric comorbidity or treatment resistance 1
• Offer motivational interviewing and brief interventions (5-30 minutes) incorporating individualized feedback on reducing or stopping cannabis 6

Diagnostic Criteria to Confirm CHS

Clinical features required:

• Stereotypical episodic vomiting resembling cyclic vomiting syndrome with ≥3 episodes annually and ≥2 episodes in past 6 months, occurring at least 1 week apart 2, 1
• Absence of nausea and vomiting between episodes 2

Cannabis use patterns required:

• Duration of cannabis use >1 year before symptom onset 2, 1
• Frequency >4 times per week on average 2, 1
• Daily use occurs in 68% of cases 2

Confirmatory criterion:

• Resolution of symptoms after cannabis abstinence for at least 6 months or duration equal to 3 typical vomiting cycles 2, 1

Common Pitfalls to Avoid

• Do not rely on conventional antiemetics alone as they are often ineffective in CHS, unlike their efficacy in other conditions 5, 7
• Do not prescribe opioids despite severe abdominal pain, as they worsen symptoms and create addiction risk 2, 3, 4
• Do not overlook the diagnosis in patients who deny or minimize cannabis use; recidivism rates are high even after diagnosis 2
• Do not assume symptom relief from cannabis use rules out CHS; paradoxically, patients often report cannabis helps their symptoms despite it being the cause 2
• Do not discharge without explicit cannabis cessation counseling and follow-up arrangements, as >40% may stop treatment over time but recurrence is common 2

Monitoring During Cannabis Withdrawal

• Monitor for depression or psychosis during withdrawal, which can occur less commonly 6
• If these complications develop, close monitoring is required and specialist psychiatric advice should be sought 6
• Provide symptomatic management for agitation and sleep disturbance during the withdrawal period 6