Cannabis Use May Reduce the Effectiveness of Standard Treatment for Cyclical Vomiting Syndrome
Among patients with cyclical vomiting syndrome, 19% used cannabis and the standard treatment (low-dose amitriptyline) worked best when patients stopped using both opioids and cannabis.
Quick Facts
What This Study Found
61% of CVS patients responded to a three-tiered treatment algorithm, with 91% of responders responding to low-dose amitriptyline alone (mean 26.5 mg). 33% used opioids and 19% used cannabis. Opioid cessation was significantly associated with treatment response (p = 0.03). While cannabis use was prevalent, the study suggested that cessation of both substances may improve treatment outcomes.
Key Numbers
61% treatment response rate; 91% of responders responded to TCA alone; mean TCA dose 26.5 mg among responders; 33% used opioids; 19% cannabis; 7% both; opioid cessation associated with treatment response (p = 0.03); IBS associated with 6.59x odds of opioid use
How They Did This
Retrospective data from consecutive newly diagnosed CVS patients at a single UK tertiary neurogastroenterology clinic (January 2016 to June 2024). Patients were advised to stop opioids and cannabis and started on low-dose amitriptyline with stepwise escalation if needed.
Why This Research Matters
Cyclical vomiting syndrome is frequently linked to cannabis use, yet the interaction between cannabis, CVS treatment, and clinical outcomes has been poorly understood. This study suggests stopping cannabis may be part of effective CVS management.
The Bigger Picture
Cannabis is paradoxically both a reported remedy for nausea and a recognized cause of cyclical vomiting syndrome (cannabinoid hyperemesis syndrome). This study adds evidence that cannabis use may interfere with standard CVS treatment, supporting cessation as part of clinical management.
What This Study Doesn't Tell Us
Retrospective design at a single tertiary center, small sample limits statistical power for cannabis-specific analyses, cannot separate cessation effects from treatment effects, patients who stopped substances may have been more motivated overall, UK healthcare context
Questions This Raises
- ?How much of the treatment response improvement is from stopping cannabis vs. the amitriptyline itself?
- ?Is cannabis-associated CVS a distinct entity from other CVS?
- ?Would prospective studies with controlled cessation protocols show clearer cannabis effects?
Trust & Context
- Key Stat:
- 19% of CVS patients used cannabis, and cessation was part of the most effective treatment approach
- Evidence Grade:
- Single-center retrospective cohort; provides real-world treatment data but limited ability to isolate cannabis-specific effects
- Study Age:
- Published 2025
- Original Title:
- Impact of Opioid and Cannabis Use on Low-Dose Amitriptyline Efficacy in Cyclical Vomiting Syndrome: A Real-World Study in the United Kingdom.
- Published In:
- Neurogastroenterology and motility, 37(6), e70007 (2025)
- Database ID:
- RTHC-06138
Evidence Hierarchy
Looks back at existing records to find patterns.
What do these levels mean? →Frequently Asked Questions
Does cannabis use affect treatment for cyclical vomiting syndrome?
In this study, CVS treatment worked best when patients stopped using cannabis and opioids alongside starting low-dose amitriptyline. Opioid cessation was statistically linked to better outcomes, and cannabis cessation was recommended as part of the treatment protocol.
How common is cannabis use among CVS patients?
19% of CVS patients in this UK study used cannabis, with an additional 7% using both cannabis and opioids.
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Cite This Study
https://rethinkthc.com/research/RTHC-06138APA
Butt, Mohsin F; Cefalo, Francesca; Sbarigia, Caterina; Dhali, Arkadeep; Corsetti, Maura. (2025). Impact of Opioid and Cannabis Use on Low-Dose Amitriptyline Efficacy in Cyclical Vomiting Syndrome: A Real-World Study in the United Kingdom.. Neurogastroenterology and motility, 37(6), e70007. https://doi.org/10.1111/nmo.70007
MLA
Butt, Mohsin F, et al. "Impact of Opioid and Cannabis Use on Low-Dose Amitriptyline Efficacy in Cyclical Vomiting Syndrome: A Real-World Study in the United Kingdom.." Neurogastroenterology and motility, 2025. https://doi.org/10.1111/nmo.70007
RethinkTHC
RethinkTHC Research Database. "Impact of Opioid and Cannabis Use on Low-Dose Amitriptyline ..." RTHC-06138. Retrieved from https://rethinkthc.com/research/butt-2025-impact-of-opioid-and
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.