Comprehensive review of cannabinoid hyperemesis syndrome: three phases, paradoxical vomiting from an antiemetic drug

A review characterized CHS as a three-phase condition (prodromal, hyperemetic, recovery) where cannabis paradoxically causes vomiting despite its established anti-emetic properties, with compulsive hot bathing as a hallmark behavior.

Galli, Jonathan A et al.·Current drug abuse reviews·2011·Moderate EvidenceReview
RTHC-00486ReviewModerate Evidence2011RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Review
Evidence
Moderate Evidence
Sample
Not reported

What This Study Found

The review synthesized existing knowledge about cannabinoid hyperemesis syndrome (CHS), describing a paradox: cannabis is well-established as an anti-emetic, yet chronic use could cause severe cyclic vomiting.

The clinical course was divided into three phases. The prodromal phase involved morning nausea and fear of vomiting. The hyperemetic phase featured severe nausea, vomiting, and abdominal pain, typically ceasing within 48 hours. The recovery phase saw symptom resolution with cannabis cessation.

Compulsive hot bathing was identified as a learned behavior that provided temporary symptom relief, with patients often spending hours in hot water. The mechanism remained unknown, though the review discussed opposing effects of THC, CBD, and cannabigerol on the emesis response.

CHS was frequently misdiagnosed due to overlapping symptoms with cyclic vomiting syndrome, leading to unnecessary diagnostic workups.

Key Numbers

Three phases identified: prodromal, hyperemetic (ceases within 48 hours), recovery. Three cannabinoids with opposing emesis effects: THC, CBD, cannabigerol.

How They Did This

Narrative review synthesizing case reports, clinical series, and pathophysiological hypotheses about cannabinoid hyperemesis syndrome.

Why This Research Matters

The comprehensive characterization of CHS phases, hallmark features, and differential diagnosis helped clinicians recognize and diagnose the condition more efficiently, potentially reducing unnecessary testing.

The Bigger Picture

CHS represented a growing clinical challenge as cannabis use increased. The paradox of an anti-emetic drug causing vomiting highlighted the complexity of cannabinoid pharmacology with chronic use.

What This Study Doesn't Tell Us

Knowledge was largely based on case reports and small series. Mechanism remained unknown. Epidemiology was poorly characterized. No validated diagnostic criteria existed at the time.

Questions This Raises

  • ?What is the mechanism by which chronic cannabis exposure switches from anti-emetic to pro-emetic?
  • ?How common is CHS among chronic cannabis users?

Trust & Context

Key Stat:
Three opposing cannabinoids may explain the anti-emetic paradox
Evidence Grade:
Comprehensive narrative review synthesizing available case literature and pathophysiological hypotheses.
Study Age:
Published in 2011. CHS is now widely recognized in emergency medicine with updated diagnostic criteria.
Original Title:
Cannabinoid hyperemesis syndrome.
Published In:
Current drug abuse reviews, 4(4), 241-9 (2011)
Database ID:
RTHC-00486

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study

Summarizes existing research on a topic.

What do these levels mean? →

Frequently Asked Questions

How can cannabis cause vomiting if it's used to treat nausea?

The review described this paradox. Cannabis contains multiple cannabinoids (THC, CBD, cannabigerol) with opposing effects on vomiting. With chronic use, the balance may shift toward pro-emetic effects through an unknown mechanism.

How is CHS diagnosed?

CHS is characterized by chronic cannabis use, cyclic nausea/vomiting episodes, compulsive hot bathing, and symptom resolution with cannabis cessation. It is often confused with cyclic vomiting syndrome and diagnosed only after extensive workups.

Read More on RethinkTHC

Cite This Study

RTHC-00486·https://rethinkthc.com/research/RTHC-00486

APA

Galli, Jonathan A; Sawaya, Ronald Andari; Friedenberg, Frank K. (2011). Cannabinoid hyperemesis syndrome.. Current drug abuse reviews, 4(4), 241-9.

MLA

Galli, Jonathan A, et al. "Cannabinoid hyperemesis syndrome.." Current drug abuse reviews, 2011.

RethinkTHC

RethinkTHC Research Database. "Cannabinoid hyperemesis syndrome." RTHC-00486. Retrieved from https://rethinkthc.com/research/galli-2011-cannabinoid-hyperemesis-syndrome

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.