Olanzapine resolved treatment-resistant cannabinoid hyperemesis syndrome in four patients

Four patients with cannabinoid hyperemesis syndrome that did not respond to standard treatments all improved after receiving olanzapine, an atypical antipsychotic.

Hsu, Jennifer et al.·Journal of psychiatric practice·2021·Preliminary EvidenceCase Report
RTHC-03210Case ReportPreliminary Evidence2021RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Case Report
Evidence
Preliminary Evidence
Sample
Not reported

What This Study Found

All four cases of treatment-refractory CHS remitted after olanzapine treatment. Olanzapine blocks multiple neurotransmitter receptors involved in nausea and vomiting. The authors suggest it may be particularly useful when CHS presents alongside psychotic symptoms or agitation.

Key Numbers

4 patients. All had treatment-refractory CHS. All remitted with olanzapine. Olanzapine targets dopamine, serotonin, histamine, and muscarinic receptors involved in emesis.

How They Did This

Case series of 4 patients with treatment-refractory cannabinoid hyperemesis syndrome treated with olanzapine at a single institution. Clinical outcomes documented before and after olanzapine initiation.

Why This Research Matters

CHS is increasingly recognized as cannabis use grows, and some cases do not respond to standard anti-emetics or hot showers. Having additional treatment options for refractory cases addresses a real clinical gap.

The Bigger Picture

Cannabis cessation remains the definitive treatment for CHS, but patients often cannot or will not stop immediately. Olanzapine could serve as a bridge treatment for acute refractory episodes, borrowing from its established role in chemotherapy-induced nausea.

What This Study Doesn't Tell Us

Only 4 cases with no control group. Cannot rule out spontaneous resolution. No standardized dosing protocol reported. Single institution.

Questions This Raises

  • ?What is the optimal olanzapine dose for CHS?
  • ?Would it work as first-line treatment?
  • ?Does it address the underlying pathophysiology or just mask symptoms?
  • ?How does it compare to haloperidol, which has also been tried for CHS?

Trust & Context

Key Stat:
4 of 4 treatment-refractory CHS cases remitted with olanzapine
Evidence Grade:
Very small case series with no controls. Preliminary signal only.
Study Age:
2021 case series.
Original Title:
Treatment of Cannabinoid Hyperemesis With Olanzapine: A Case Series.
Published In:
Journal of psychiatric practice, 27(4), 316-321 (2021)
Database ID:
RTHC-03210

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / Observational
Case Report / Animal StudyOne case or non-human subjects
This study

Describes what happened to one person or a small group.

What do these levels mean? →

Frequently Asked Questions

What is cannabinoid hyperemesis syndrome?

CHS is a condition in chronic cannabis users characterized by severe cyclical nausea, vomiting, and abdominal pain. It typically resolves only with cannabis cessation, though hot showers provide temporary relief.

Why might olanzapine work for CHS?

Olanzapine blocks multiple neurotransmitter receptors (dopamine, serotonin, histamine, muscarinic) involved in nausea and vomiting pathways, similar to its mechanism in treating chemotherapy-induced nausea.

Read More on RethinkTHC

Cite This Study

RTHC-03210·https://rethinkthc.com/research/RTHC-03210

APA

Hsu, Jennifer; Herrmann, Zachary; Kashyap, Saurabh; Claassen, Cynthia. (2021). Treatment of Cannabinoid Hyperemesis With Olanzapine: A Case Series.. Journal of psychiatric practice, 27(4), 316-321. https://doi.org/10.1097/PRA.0000000000000564

MLA

Hsu, Jennifer, et al. "Treatment of Cannabinoid Hyperemesis With Olanzapine: A Case Series.." Journal of psychiatric practice, 2021. https://doi.org/10.1097/PRA.0000000000000564

RethinkTHC

RethinkTHC Research Database. "Treatment of Cannabinoid Hyperemesis With Olanzapine: A Case..." RTHC-03210. Retrieved from https://rethinkthc.com/research/hsu-2021-treatment-of-cannabinoid-hyperemesis

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.