A CB1 Receptor Blocker Rapidly Reversed the Effects of Synthetic Cannabinoid Intoxication in Mice
The CB1 receptor antagonist AM251 rapidly reversed the hypothermic and sedative effects of a synthetic cannabinoid in mice, suggesting CB1 blockers could serve as emergency antidotes for cannabinoid overdose.
Quick Facts
What This Study Found
Researchers induced cannabinoid intoxication in mice using the synthetic CB1 agonist CB-13, which caused significant hypothermia and visible sedation. Twenty minutes after CB-13 administration, the CB1 receptor antagonist/inverse agonist AM251 was given.
AM251 rapidly reversed the hypothermic effects of CB-13, returning body temperature toward normal. There was also a subjective reversal of visible sedation. The key finding was that the antagonist worked therapeutically (after intoxication had already occurred), not just prophylactically (before exposure).
The authors argue that with the emergence of extremely potent synthetic cannabinoids ("Spice," "Black Mamba") causing life-threatening intoxications and deaths, a single-dose cannabinoid receptor antagonist could serve as a life-saving antidote, analogous to naloxone for opioid overdose.
Key Numbers
AM251 administered 20 minutes after CB-13 intoxication. Hypothermic effect was rapidly reversed. CB1 receptor antagonists have been widely used in research with established safety profiles for single doses.
How They Did This
Biozzi ABH mice received the synthetic CB1 agonist CB-13. Body temperature was monitored as a measure of cannabinoid intoxication. AM251 was administered 20 minutes after CB-13 to test therapeutic (post-intoxication) reversal. Sedation was assessed observationally.
Why This Research Matters
Synthetic cannabinoid overdoses have caused numerous hospitalizations and deaths, and currently there is no specific antidote. This proof-of-concept study demonstrates that a CB1 receptor antagonist can reverse at least some cannabinoid effects after they have already begun, supporting the development of an emergency antidote for clinical use.
The Bigger Picture
The opioid crisis led to widespread naloxone availability as an overdose antidote. As synthetic cannabinoids become more potent and more dangerous, a similar approach for cannabinoid overdose becomes more relevant. This study provides preclinical evidence that such an antidote is pharmacologically feasible.
What This Study Doesn't Tell Us
Mouse study using a single synthetic cannabinoid and a single antagonist. Many synthetic cannabinoids in recreational use may have off-target effects not mediated by CB1 receptors, which an antagonist would not reverse. AM251 is a research tool, not a clinical drug. The study measured hypothermia as a proxy for intoxication; more severe effects (seizures, psychosis, cardiovascular collapse) were not modeled.
Questions This Raises
- ?Would a CB1 antagonist reverse the most dangerous effects of synthetic cannabinoid intoxication (cardiovascular collapse, seizures)?
- ?Could a clinical-grade CB1 antagonist be developed and deployed like naloxone?
- ?What are the side effects of acutely blocking CB1 receptors in someone who is a chronic cannabis user?
Trust & Context
- Key Stat:
- CB1 antagonist rapidly reversed cannabinoid intoxication when given 20 minutes after exposure
- Evidence Grade:
- Preliminary evidence from a single animal study demonstrating proof of concept.
- Study Age:
- Published in 2017. Synthetic cannabinoid overdose emergencies have continued to increase.
- Original Title:
- Antidote to cannabinoid intoxication: the CB1 receptor inverse agonist, AM251, reverses hypothermic effects of the CB1 receptor agonist, CB-13, in mice.
- Published In:
- British journal of pharmacology, 174(21), 3790-3794 (2017)
- Authors:
- Pryce, Gareth(10), Baker, David(10)
- Database ID:
- RTHC-01493
Evidence Hierarchy
Tests effects in animals (usually mice or rats), not humans.
What do these levels mean? →Frequently Asked Questions
Is there an antidote for cannabis or synthetic cannabinoid overdose?
Not yet in clinical use. This study demonstrated in mice that a CB1 receptor antagonist can reverse some effects of synthetic cannabinoid intoxication. Development of a clinical antidote for human use would require significant further research and regulatory approval.
Would this work for natural cannabis intoxication too?
Theoretically, a CB1 antagonist could reverse THC's effects since THC acts primarily through CB1 receptors. However, natural cannabis intoxication is almost never life-threatening, so the clinical need is much greater for synthetic cannabinoid overdoses, which can be fatal.
Read More on RethinkTHC
- 420-sober-survival-guide
- CBT-cannabis-recovery
- THC-purity-potency-label-meaning
- cannabis-relapse-cycle-pattern
- cold-turkey-vs-taper-quit-weed
- dab-concentrate-addiction-withdrawal
- dating-sober-after-quitting-weed
- delta-8-addiction-withdrawal
- edible-addiction-withdrawal-different
- edibles-psychosis-emergency-room
- exercise-quitting-weed-anxiety-brain
- grieving-quitting-weed-loss
- healthiest-way-to-consume-cannabis
- help-someone-quit-weed
- how-cannabis-products-made-concentrates-edibles
- how-to-quit-weed
- journaling-weed-withdrawal
- laced-weed-fentanyl-contaminated-vape
- legal-weed-vs-street-weed-quality-safety
- marijuana-anonymous-SMART-recovery-compare
- meditation-mindfulness-weed-withdrawal
- partner-still-smokes-weed
- partner-still-smokes-weed-quitting
- pink-cloud-sobriety-cannabis
- quit-weed-cold-turkey
- quit-weed-or-cut-back-which-is-better
- quit-weed-regret-went-back
- quitting-dabs-withdrawal
- quitting-edibles-withdrawal
- quitting-weed-20s
- quitting-weed-30s
- quitting-weed-after-years
- quitting-weed-during-crisis-divorce-job-loss
- quitting-weed-exercise
- quitting-weed-grief-loss-coping
- quitting-weed-legal-state
- quitting-weed-success-stories
- quitting-weed-triggers-environment
- relapsed-smoking-weed-what-to-do
- relapsed-weed
- sativa-vs-indica-difference-myth
- should-i-quit-weed
- sober-music-festival-concert-without-weed
- supplements-weed-withdrawal
- telling-friends-quitting-weed
- weed-potency-withdrawal
- weed-relapse-prevention-plan
- weed-relapse-why-it-happens
- weed-ritual-replacement
- weed-ruined-relationships
- weed-social-media-triggers-quit
Cite This Study
https://rethinkthc.com/research/RTHC-01493APA
Pryce, Gareth; Baker, David. (2017). Antidote to cannabinoid intoxication: the CB1 receptor inverse agonist, AM251, reverses hypothermic effects of the CB1 receptor agonist, CB-13, in mice.. British journal of pharmacology, 174(21), 3790-3794. https://doi.org/10.1111/bph.13973
MLA
Pryce, Gareth, et al. "Antidote to cannabinoid intoxication: the CB1 receptor inverse agonist, AM251, reverses hypothermic effects of the CB1 receptor agonist, CB-13, in mice.." British journal of pharmacology, 2017. https://doi.org/10.1111/bph.13973
RethinkTHC
RethinkTHC Research Database. "Antidote to cannabinoid intoxication: the CB1 receptor inver..." RTHC-01493. Retrieved from https://rethinkthc.com/research/pryce-2017-antidote-to-cannabinoid-intoxication
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.