Cannabinoid Hyperemesis Syndrome: Pathophysiology and Clinical Management
Abstract
Comprehensive review of CHS pathophysiology implicates TRPV1 receptor dysregulation and hypothalamic temperature dysregulation. Hot water bathing behavior explained by TRPV1 activation. Capsaicin cream and haloperidol identified as most evidence-supported acute treatments.
Study Summary
This comprehensive narrative review synthesized evidence on cannabinoid hyperemesis syndrome (CHS) — a paradoxical condition of cyclical vomiting in heavy, long-term cannabis users. The review covered 87 case reports, case series, and observational studies. CHS pathophysiology is proposed to involve: (1) TRPV1 receptor desensitization in the gut with chronic THC exposure, leading to loss of antiemetic tone; (2) hypothalamic temperature dysregulation via CB1 receptor downregulation; (3) accumulation of lipophilic cannabinoids in adipose tissue with slow release. The characteristic hot water bathing behavior is explained by cutaneous TRPV1 activation providing temporary symptomatic relief. Capsaicin cream (applied to abdomen) and haloperidol (IV) were identified as the most evidence-supported acute treatments, with cessation of cannabis use as the only definitive cure. Ondansetron and standard antiemetics are largely ineffective.
Key Findings
- 1TRPV1 desensitization and CB1 downregulation in gut proposed as primary CHS mechanisms
- 2Hot water bathing behavior explained by cutaneous TRPV1 activation — temporary relief
- 3Capsaicin cream (topical abdominal) and IV haloperidol most evidence-supported acute treatments
- 4Standard antiemetics (ondansetron, metoclopramide) largely ineffective for CHS
- 5Cannabis cessation is the only definitive cure — symptoms resolve within days to weeks
Clinical Implications
- CHS should be considered in any heavy cannabis user presenting with cyclical vomiting
- Capsaicin cream is a low-risk, inexpensive first-line option for acute CHS management
- Clinicians should counsel patients that standard antiemetics will not resolve CHS
- Cannabis cessation counseling is the most important clinical intervention
Study Limitations
- No RCT evidence for any CHS treatment — all recommendations based on case series
- CHS prevalence likely underestimated due to underdiagnosis and underreporting
- Pathophysiology remains incompletely understood; proposed mechanisms are largely theoretical
- Long-term outcomes after cannabis cessation not well characterized