What is the management and treatment approach for a young to middle-aged adult with a history of long-term and frequent cannabis use presenting with cannabis hyperemesis syndrome?

Cannabis Hyperemesis Syndrome Management

Definitive Treatment

Complete and permanent cessation of all cannabis use is the only definitive cure for cannabis hyperemesis syndrome and must be the primary treatment goal. 1, 2, 3

Resolution of symptoms occurs after 6 months of complete abstinence or a duration equal to 3 typical vomiting cycles, which serves as both diagnostic confirmation and therapeutic endpoint. 1, 2

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Acute Episode Management in the Emergency Department

Initial Assessment and Diagnosis

Suspect CHS in any patient under 50 years old with:

• Cannabis use >1 year before symptom onset and frequency >4 times weekly 1, 2
• Stereotypical episodic vomiting (≥3 episodes annually) with acute onset lasting <1 week 2
• Compulsive hot water bathing behavior for symptom relief (present in 71-91% of cases) 1, 2, 4
• Abdominal pain (86% of patients) 4

First, rule out life-threatening conditions: acute abdomen, bowel obstruction, mesenteric ischemia, pancreatitis, and myocardial infarction before attributing symptoms solely to CHS. 1, 2, 3

Acute Pharmacologic Management Algorithm

First-line therapy: Haloperidol 5 mg IV as the initial dose, which reduces hospital length of stay by nearly 50% (6.7 vs 13.9 hours, p=0.014) compared to standard antiemetics. 2, 3

• For breakthrough symptoms: haloperidol 0.5-2 mg IV every 4-6 hours 3
• Add lorazepam 2 mg IV for anxiolysis and enhanced symptom control 3
• Have diphenhydramine 25-50 mg IV available for potential dystonic reactions 3
• Monitor for QT prolongation and extrapyramidal effects 3

Second-line options if haloperidol contraindicated:

• Droperidol (butyrophenone class, similar efficacy to haloperidol) 2
• Promethazine 12.5-25 mg IV (central line only) every 4 hours 3
• Olanzapine 5-10 mg PO daily 1, 3
• Benzodiazepines alone for sedating and anxiolytic effects 2, 5

Adjunctive therapy: Topical capsaicin 0.1% applied to the abdomen activates TRPV1 receptors and provides consistent symptom relief. 1, 2, 3

Ondansetron has limited efficacy in CHS compared to conventional antiemetic use in other conditions and should not be first-line. 1, 3

Absolutely avoid opioids as they worsen nausea and carry high addiction risk in this population. 1, 2, 3

Supportive Care

• IV fluids for dehydration and electrolyte abnormalities 3, 5
• Allow hot showers/baths (hydrothermotherapy) for temporary symptomatic relief 1

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Long-Term Preventive Management

Cannabis Cessation Counseling

Strongly counsel for complete cannabis cessation as both diagnostic and the only definitive treatment. 1, 2, 3

Address common barriers:

• Patients often report cannabis helps their symptoms, leading to continued use and worsening of the underlying condition 3
• Many remain uncertain about cannabis's role and attribute symptoms to food, alcohol, stress, or pre-existing GI disorders 3
• 86% of patients who stopped cannabis use achieved complete symptom resolution 4

Pharmacologic Prevention

Tricyclic antidepressants (amitriptyline) are the mainstay of preventive therapy:

• Start at 25 mg at bedtime 1, 2, 3
• Titrate weekly to reach minimal effective dose of 75-100 mg 1, 2
• Dose range 50-200 mg/day for long-term management 6
• Once in remission, taper slowly 6

Psychological Support

• Co-management with psychiatry for patients with extensive psychiatric comorbidity or treatment resistance 1
• Address anxiety and depression, which are common comorbidities 1

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Special Perioperative Considerations

Patients with CHS undergoing surgery require enhanced prophylactic antiemetic therapy due to increased risk for post-anesthesia intractable vomiting. 2

Multimodal antiemetic prophylaxis differs from standard PONV protocols:

• Prioritize butyrophenones (haloperidol or droperidol) 2
• Add benzodiazepines for stress-mediated component 2
• Add topical capsaicin 0.1% to abdomen 2

Anesthetic adjustments:

• Cannabis users may require higher doses of anesthetic agents 2
• Consider processed depth of anesthesia EEG monitoring (BIS) for heavy users 2
• Anticipate higher postoperative analgesic requirements 2
• Use multimodal non-opioid analgesia strategies 2

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Critical Diagnostic Pitfalls

CHS is frequently underdiagnosed or misdiagnosed due to limited clinician awareness, leading to extensive unnecessary testing. 2, 3, 7

Hot water bathing behavior is not pathognomonic: while present in 71% of CHS patients, it also occurs in 44% of cyclic vomiting syndrome patients and cannot reliably distinguish between the two conditions. 2

Standard antiemetics typically fail in CHS, which should raise clinical suspicion when conventional therapy is ineffective. 7, 5

Cannabis withdrawal syndrome can begin after 48 hours of abstinence and may include nausea and stomach pain, potentially confusing the clinical picture. 3

Modern cannabis products contain dramatically higher THC concentrations than historical products, increasing CHS risk regardless of delivery method (smoking, vaping, or edibles). 2