The Best Available Treatments for Cannabinoid Hyperemesis Syndrome: Benzodiazepines, Haloperidol, and Capsaicin | Research

The takeaway

A systematic review of 63 studies found benzodiazepines, haloperidol, and capsaicin cream were the most frequently reported effective treatments for acute CHS, while tricyclic antidepressants showed promise for long-term management.

Readers or clinicians dealing with cannabinoid hyperemesis syndrome.

63 studies covering 205 patients; hot showers universally effective across all studies

What the researchers found

The systematic review analyzed 63 eligible articles covering 205 CHS patients. The evidence quality was generally low: only 4 prospective studies (level 2), 3 retrospective studies (level 3), 12 case series (level 4), and 44 case reports (level 5).

For acute treatment, benzodiazepines (particularly lorazepam) were the most frequently cited effective medication, followed by haloperidol and topical capsaicin cream. Hot showers and baths were universally effective across all case-level studies.

For long-term management, tricyclic antidepressants showed the most promise in the limited prospective data. Standard antiemetics (ondansetron, promethazine, diphenhydramine) were mentioned but authors did not consistently endorse their efficacy.

Importantly, conventional antiemetics that work well for other causes of vomiting were frequently associated with treatment failure in CHS, underscoring the unique pathophysiology of this condition.

Why it matters

CHS has become increasingly common with cannabis legalization, yet emergency physicians and clinicians have had little evidence-based guidance for treatment. This systematic review provides the most comprehensive summary of treatment options available, even though the evidence base remains limited to mostly case reports.

The numbers in context

1,262 articles screened. 63 included. 205 human subjects total. 4 level-2 studies (64 subjects). 3 level-3 studies (43 subjects). 12 level-4 case series (54 subjects). 44 level-5 case reports (44 subjects). Hot showers: universally effective.

How the study worked

Systematic review searching Medline, PsycINFO, DARE, OpenGrey, Google Scholar, and the Cochrane Library from inception to February 2017. Evidence was graded using Oxford Center for Evidence-Based Medicine guidelines. 1,262 articles were screened, 63 included.

What this study cannot tell us

The vast majority of evidence comes from case reports and case series (level 4-5), the weakest forms of clinical evidence. No randomized controlled trials existed at the time of this review. Publication bias likely favors reporting of successful treatments. The heterogeneity of dosing, timing, and outcome measures across studies limits firm conclusions.

How to read the evidence

Moderate evidence: systematic review with comprehensive search, but underlying evidence is mostly case-level.

When this study was published

Published in 2017. CHS treatment research has continued to evolve.

The bigger picture

CHS represents a clinical challenge because it defies the usual antiemetic approach. The finding that benzodiazepines and antipsychotics outperform traditional antiemetics suggests CHS involves different neural pathways than standard nausea and vomiting. The emergence of topical capsaicin as a treatment option is particularly interesting, as it provides a non-sedating alternative.

Questions still open

Why are benzodiazepines and antipsychotics more effective than standard antiemetics for CHS? Could capsaicin cream become a first-line treatment given its ease of use and lack of sedation? When will randomized controlled trials for CHS treatment be conducted?

Common questions

What is the best treatment for CHS?

Based on this review, benzodiazepines (especially lorazepam) are the most frequently reported effective acute treatment, followed by haloperidol and topical capsaicin cream applied to the abdomen. Hot showers provide temporary but reliable relief. For long-term management, tricyclic antidepressants showed promise. However, the only definitive cure remains stopping cannabis use.

Why does capsaicin cream help CHS?

Capsaicin activates TRPV1 receptors, the same heat-sensitive receptors that hot water activates. Applying capsaicin cream to the abdomen may produce similar receptor stimulation to hot bathing, providing relief through the same mechanism but without the need for hot water.

Read the original research

Pharmacologic Treatment of Cannabinoid Hyperemesis Syndrome: A Systematic Review.

Pharmacotherapy, 37(6), 725-734

View on PubMed ↗Publisher’s paper ↗

Citation

Richards, John R; Gordon, Brent K; Danielson, Aaron R; Moulin, Aimee K. (2017). Pharmacologic Treatment of Cannabinoid Hyperemesis Syndrome: A Systematic Review.. Pharmacotherapy, 37(6), 725-734. https://doi.org/10.1002/phar.1931