What is the best course of action for someone who experiences delirium, altered mental status, nausea, and vomiting after smoking cannabis (marijuana)?

Cannabis Hyperemesis Syndrome: Immediate Action Required

Your friend needs to stop smoking cannabis completely—this is cannabinoid hyperemesis syndrome (CHS), and cannabis cessation is the only definitive cure. 1, 2

What Is Happening

Your friend's symptoms—delirium, altered mental status, nausea, and vomiting after cannabis use—are characteristic of CHS, a paradoxical condition where chronic cannabis use causes the exact symptoms it's supposed to relieve. 1, 3 This occurs with:

• Regular cannabis use for more than 1 year before symptoms begin 1, 2
• Frequency of use greater than 4 times weekly (often daily) 4, 1
• Stereotypical episodes of vomiting occurring at least 3 times annually 1, 2

The altered mental status and delirium are concerning features that require immediate medical attention to rule out life-threatening conditions. 2

Immediate Steps

Seek Emergency Care If:

• Delirium or altered mental status is present (this requires urgent evaluation) 2
• Severe dehydration develops (poor skin turgor, dry mucous membranes, confusion) 2
• Symptoms suggest other dangerous conditions: severe abdominal pain, inability to keep down any fluids, chest pain 2

Emergency Department Will:

• Rule out acute abdomen, bowel obstruction, mesenteric ischemia, pancreatitis, myocardial infarction, and acute intermittent porphyria (a rare but serious mimic of CHS) 2, 5
• Provide IV fluids for dehydration 2
• Consider topical capsaicin (0.1%) applied to the abdomen for symptom relief 1, 2
• Use haloperidol, promethazine, or olanzapine for acute nausea control (these work better than standard antiemetics like ondansetron in CHS) 1, 2, 6
• Avoid opioids as they worsen nausea and carry addiction risk 2

Temporary Relief at Home (While Awaiting Medical Care):

• Hot showers or baths provide temporary symptom relief—this is actually a diagnostic clue for CHS, reported in 71% of cases 1, 2, 6

The Only Real Solution

Complete cannabis cessation is the definitive treatment and the only intervention that leads to long-term resolution. 1, 2 Symptoms should resolve after abstinence for at least 6 months or a duration equal to 3 typical vomiting cycles. 4, 1

Why Stopping Is Critical:

• Any continued cannabis use will perpetuate the syndrome 1, 7
• Many patients mistakenly believe cannabis helps their symptoms, leading to continued use and worsening of the condition 2
• Modern cannabis products have higher THC concentrations, increasing CHS risk 2

Long-Term Management After Cessation

Once your friend commits to stopping cannabis:

• Tricyclic antidepressants (amitriptyline) are the mainstay of prevention therapy: Start at 25 mg at bedtime, titrate weekly to reach 75-100 mg for maintenance 1, 2, 7
• Cannabis cessation counseling is essential 1
• Psychological support may be beneficial as anxiety and depression are common comorbidities 1
• Consider psychiatry co-management if there is extensive psychiatric comorbidity or treatment resistance 1

Critical Pitfalls to Avoid

• Do not assume cannabis is helping—patients often report cannabis relieves symptoms, but this perpetuates the underlying condition 2
• CHS is frequently misdiagnosed as cyclic vomiting syndrome, gastroenteritis, or other GI disorders due to limited clinician awareness 2, 3
• Beware of cannabis withdrawal syndrome (CWS)—after 48 hours of abstinence, patients may develop nausea and stomach pain from withdrawal itself, which can be managed supportively with gabapentin, nabilone, or dronabinol 4, 8
• Watch for dystonic reactions—cannabis users may have altered drug metabolism and can develop acute dystonia even with low-dose metoclopramide or haloperidol 8

Bottom Line

The delirium and altered mental status require immediate medical evaluation to exclude dangerous conditions. Once CHS is confirmed, the only path forward is complete and permanent cannabis cessation—no amount of symptomatic treatment will resolve this condition while cannabis use continues. 1, 2