How do you manage hyperemesis in a patient who uses marijuana?

Management of Cannabinoid Hyperemesis Syndrome (CHS)

For acute hyperemesis in marijuana users, first-line treatment is parenteral benzodiazepines (specifically lorazepam), with haloperidol as second-line, topical capsaicin 0.1% cream to the abdomen as adjunctive therapy, and complete cannabis cessation as the only definitive cure. 1, 2

Immediate Diagnostic Differentiation

Before treating, distinguish between two opposite conditions that both cause vomiting in cannabis users:

• Cannabinoid Hyperemesis Syndrome (CHS): Vomiting occurs during active chronic cannabis use (≥4 times weekly for >1 year), with stereotypical episodic vomiting ≥3 times annually 1, 2, 3
• Cannabis Withdrawal Syndrome (CWS): Vomiting occurs after stopping cannabis, with symptom onset 24-72 hours after cessation in heavy users (>1.5 g/day or >2-3 times daily) 1

The pathognomonic feature of CHS is compulsive hot water bathing behavior, present in 44-71% of cases, though this also occurs in 44% of cyclic vomiting syndrome patients 1, 3

Acute Management Protocol for CHS

First-Line Therapy

• Benzodiazepines (lorazepam) are the most effective acute treatment for CHS-related nausea and vomiting based on multiple prospective studies 1, 2
• These provide both antiemetic effects and address the stress-mediated component through anxiolytic and sedating properties 3

Second-Line Therapy

• Haloperidol or droperidol (butyrophenones) reduce hospital length of stay by nearly 50% (6.7 vs 13.9 hours, p=0.014) 4, 1, 3
• These antipsychotics have superior efficacy compared to standard antiemetics 2, 5

Adjunctive Therapy

• Topical capsaicin 0.1% cream applied to the abdomen activates TRPV1 receptors and provides consistent symptom relief 1, 2, 3, 5
• Hot showers/baths (hydrothermotherapy) provide temporary symptomatic relief and serve as a diagnostic clue 2, 6

What NOT to Use

• Avoid opioids entirely - they worsen nausea, carry high addiction risk, and do not address the underlying pathophysiology 1, 2, 3
• Ondansetron has limited efficacy in CHS compared to conventional antiemetic use in other conditions 1, 2

Critical Exclusions Before Diagnosis

Rule out life-threatening conditions first: acute abdomen, bowel obstruction, mesenteric ischemia, pancreatitis, and myocardial infarction 1, 2, 3

Definitive Treatment: Cannabis Cessation

• Complete cannabis cessation is the only definitive cure and must be strongly counseled 1, 2, 3
• Symptoms require at least 6 months of continuous abstinence or duration equal to 3 typical vomiting cycles for complete resolution 1, 2, 3
• This 6-month abstinence with complete symptom resolution is the gold standard diagnostic criterion that distinguishes CHS from cyclic vomiting syndrome 3

Long-Term Preventive Therapy

• Tricyclic antidepressants (amitriptyline) are the mainstay of preventive therapy 1, 2, 3
• Start at 25 mg at bedtime, titrate weekly by 25 mg increments to reach minimal effective dose of 75-100 mg 1, 2, 3

Management of Cannabis Withdrawal Syndrome (If Applicable)

If vomiting occurs after stopping cannabis (not during active use):

• Supportive care is the mainstay, with loperamide for diarrhea and GI distress 1
• Consider gabapentin, nabilone, nabiximols, or dronabinol for significant withdrawal symptoms 4, 1
• Symptoms peak between days 2-6 and the acute phase lasts 1-2 weeks 1
• Avoid opioids due to worsening nausea and addiction risk 1

Perioperative Considerations

For patients requiring surgery who have CHS or heavy cannabis use:

• Provide enhanced prophylactic antiemetic therapy perioperatively due to increased risk for post-anesthesia intractable vomiting 3
• Consider additional PONV prophylaxis for patients consuming >1.5 g/day inhaled cannabis, >20 mg/day THC oil, or >300 mg/day CBD oil 4
• Anticipate higher anesthetic requirements to achieve adequate depth of anesthesia 4, 3
• Expect higher postoperative analgesic requirements and use multimodal non-opioid strategies 4, 3

Common Pitfalls

• CHS is frequently underdiagnosed due to limited clinician awareness, leading to extensive unnecessary testing 3, 7
• Hot water bathing behavior, while suggestive, is not pathognomonic as it occurs in both CHS and cyclic vomiting syndrome 3
• The route of cannabis administration (smoking, vaping, edibles) does not matter - total THC dose and duration of use are the critical factors 3