Propranolol and Cannabinoid Hyperemesis Syndrome
There is no evidence that propranolol helps with cannabinoid hyperemesis syndrome (CHS), and it should not be used for this condition. The provided evidence contains no guideline recommendations, research studies, or mechanistic rationale supporting propranolol use in CHS.
Evidence-Based Treatments for CHS
The confusion may arise from propranolol's use in other conditions, but for CHS specifically, the following treatments are supported by guidelines and research:
Acute Management in the Emergency Department
Haloperidol is the most effective acute treatment, reducing hospital length of stay by nearly 50% (6.7 vs 13.9 hours, p=0.014) compared to standard antiemetics 1. This butyrophenone antipsychotic works through dopamine receptor blockade and sedation 2, 3.
Benzodiazepines (particularly lorazepam) are highly effective for acute symptom control by:
- Decreasing CB1 receptor activation in the frontal cortex 4
- Providing sedative and anxiolytic effects that address the stress-mediated component 1, 4
- Reducing anticipation of nausea and vomiting through CNS effects 4
Topical capsaicin (0.1%) applied to the abdomen activates TRPV1 receptors and provides consistent symptomatic relief 5, 6, 1, 2.
Standard antiemetics like ondansetron often fail in CHS, unlike their efficacy in chemotherapy-induced nausea 6, 2.
Long-Term Management
Tricyclic antidepressants (amitriptyline) are the mainstay of preventive therapy:
- Start at 25 mg at bedtime 5, 6
- Titrate weekly to reach minimal effective dose of 75-100 mg 5, 6
- Continue as maintenance therapy 2
Complete cannabis cessation is the only definitive cure and should be strongly emphasized through counseling 5, 6, 1, 7, 3.
Critical Diagnostic Features
CHS should be suspected when patients present with:
- Stereotypical episodic vomiting (≥3 episodes annually) 5, 6
- Cannabis use >4 times weekly for >1 year before symptom onset 5, 6
- Pathognomonic hot water bathing behavior (present in 44-71% of cases) 5, 1
Common Pitfall
Avoid opioids as they worsen nausea and carry high addiction risk in this population 5, 6, 1. This is a critical error frequently made when CHS is misdiagnosed as other causes of abdominal pain 2, 8.