A Severe Case of Cannabis Hyperemesis That Worsened With Prescription THC | Research

The takeaway

A case report described a patient whose cannabis hyperemesis syndrome worsened when given prescription dronabinol (synthetic THC), providing clinical evidence that THC itself drives the condition, and who became symptom-free after 12 months of abstinence.

Cannabis users experiencing unexplained vomiting and clinicians who may encounter undiagnosed CHS.

Symptoms worsened with prescription THC, then resolved after 12 months of abstinence

What the researchers found

This case report described a patient with severe cannabinoid hyperemesis syndrome (CHS) that was notable for two reasons.

First, the patient's symptoms worsened when she received dronabinol (a synthetic isomer of THC), providing what the authors called "first direct clinical evidence" that THC plays a key role in CHS pathogenesis. This strengthens the case that THC, rather than other cannabis compounds, drives the condition.

Second, the patient experienced an extended diagnostic odyssey with multiple hospital stays and extensive workups before she herself discovered the correct diagnosis via internet research. This pattern of delayed diagnosis is common in CHS because clinicians typically associate cannabis with anti-nausea effects, not vomiting. The patient became symptom-free during 12 months of confirmed cannabis abstinence.

Why it matters

The worsening of symptoms with prescription THC is a particularly telling observation, as it isolates THC from the many other compounds in cannabis. This case also highlights the ongoing problem of CHS being misdiagnosed or unrecognized, leading to unnecessary medical interventions.

The numbers in context

12 months of controlled abstinence with complete symptom resolution. Multiple hospital stays with extensive workups before correct diagnosis.

How the study worked

This was a single case report published in a clinical neuropharmacology journal, describing the clinical course, diagnostic challenges, and treatment outcome.

What this study cannot tell us

Single case reports cannot establish causality or generalize to all CHS patients. The patient may have had unique characteristics that made her particularly susceptible. The mechanism by which THC causes emesis paradoxically remains incompletely understood.

How to read the evidence

This is a single case report. While it provides a compelling clinical observation, case reports represent the lowest level of clinical evidence.

When this study was published

Published in 2016. Recognition and diagnosis of cannabinoid hyperemesis syndrome has improved since then.

The bigger picture

This case contributes to the growing understanding of CHS by providing evidence that THC specifically (rather than other cannabinoids or contaminants) drives the syndrome. The delayed diagnosis pattern underscores the need for greater clinical awareness.

Questions still open

Could specific genetic factors explain why some heavy cannabis users develop CHS while others do not? Would CBD without THC also trigger CHS symptoms?

Common questions

Why did prescription THC make the vomiting worse?

Dronabinol is a synthetic version of THC. The fact that it worsened symptoms supports the theory that THC itself triggers CHS, even when taken in a pharmaceutical form without the other compounds found in smoked cannabis.

How common is delayed diagnosis of CHS?

Delayed diagnosis is very common with CHS. Because cannabis is widely known for its anti-nausea properties, many clinicians do not consider it as a cause of vomiting. Patients often undergo extensive (and unnecessary) testing before the connection to cannabis use is identified.

Read the original research

An Overlooked Victim of Cannabis: Losing Several Years of Well-being and Inches of Jejunum on the Way to Unravel Her Hyperemesis Enigma.

Clinical neuropharmacology, 39(1), 53-4

View on PubMed ↗Publisher’s paper ↗

Citation

Bonnet, Udo. (2016). An Overlooked Victim of Cannabis: Losing Several Years of Well-being and Inches of Jejunum on the Way to Unravel Her Hyperemesis Enigma.. Clinical neuropharmacology, 39(1), 53-4. https://doi.org/10.1097/WNF.0000000000000118