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Recognizing acute cannabis intoxication

Toth, Haley RN; Mann, Cleo RN; Parsh, Bridget EdD, RN, CNS

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doi: 10.1097/01.NURSE.0000827208.59594.c3
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I am an RN working in a state where recreational cannabis use is legal. Some of my patients have informed me that they ingest cannabis edibles. How do I recognize acute cannabis intoxication in adults?–DO, CALIF.

Haley Toth, RN; Cleo Mann, RN; and Bridget Parsh, EdD, RN, CNS, reply–Cannabinoids are unique chemical compounds specific to Cannabis sativa.1 Over 100 different cannabinoids have been identified, including delta-9 tetrahydrocannabinol (THC). This is the principal psychoactive component that is responsible for the euphoric effects or the “high” desired by many cannabis users.

The term “edibles” is commonly used to refer to food products containing cannabis.2 Typically, edibles are sought out for recreational use due to their greater concentration of THC. Edibles are available in numerous forms including baked goods, candies, gummies, lozenges, butter, oils, and beverages. In states where recreational cannabis has been legalized, these products are available for purchase at dispensaries. Many individuals make edibles at home, so sales records likely underrepresent consumption.2

The recreational use of cannabis, including edibles, is now legal in 18 states and Washington, D.C., despite being classified as a Schedule I substance under federal law (no currently accepted medical use and a high potential for abuse).3,4 This change reflects the growing support for the legalization of recreational cannabis and may contribute to a change in perception of harm and social norms surrounding recreational cannabis use.2,5

Acute THC intoxication

Current literature suggests acute THC intoxication is more common when using edibles compared with other forms of consumption such as smoking or vaping.6 Accurate dosing is difficult to determine due to the delayed and variable effects of the edibles. This may lead to excessive ingestion if the user does not initially feel the desired effects.

Inaccurate and inconsistent labeling of edible THC products is another risk factor for severe toxicity.7 Because cannabis is illegal at the federal level, cannabis products are not subjected to the same level of oversight as other drugs such as alcohol.1 Manufacturing standards vary by state and are relatively inconsistent. According to one study, out of the 75 edible products that were tested, only 17% were accurately labeled, with 23% of those containing underlabeled THC content.7 The combination of highly appetizing and underlabeled products significantly increases the chances of accidental overdose.6,7

Research has shown that the threshold for intoxication occurs with the consumption of approximately 10-30 mg of THC; however, this can vary widely depending on the patient's metabolism and tolerance to THC.1,6 Studies have shown that chronic users of THC products typically develop a higher tolerance over time when compared with casual users.1

When assessing a patient with known or suspected cannabis use, it is important to obtain a detailed health history. The assessment should include questions regarding a personal and family history of substance use or mental health disorders.8 Environmental stressors may be an additional factor in the use of cannabis and should be discussed.

Acute THC intoxication is a clinical diagnosis in adults. Signs and symptoms in adults include tachycardia, BP changes (hypertension, or in older adults, orthostatic hypotension), tachypnea, conjunctival injection, dry mouth, increased appetite, nystagmus, ataxia, slurred speech, euphoria, perceptual changes, and psychomotor impairment.

Typically, episodes of acute THC intoxication will resolve with time and generally do not require medical intervention.9 Screen for co-ingestions and consider an EKG, especially if chest pain is present.9 Caregivers are encouraged to provide supportive care. Most patients can be managed with a dimly lit room, reassurance, and decreased stimulation.

Interprofessional teamwork is encouraged when caring for patients who use cannabis edibles recreationally.8 This includes consultations with the patient's primary care provider and other specialists. Some of the symptoms associated with cannabis use, including anxiety and sleep disturbances, may be better addressed by specialists in these areas.8 Referrals to healthcare professionals specializing in psychiatry, pain management, sleep, and behavioral health should be considered based on the individual needs of the patient.

As the use of THC edibles continues to grow, it is increasingly important for nurses to become familiar with the signs and symptoms of acute THC intoxication.

Precautions for patients

  • Some people who use cannabis develop cannabis use disorder, which has symptoms such as craving, withdrawal, lack of control, and negative effects on personal and professional responsibilities. Adolescents using cannabis are four to seven times more likely than adults to develop cannabis use disorder.
  • Cases of unintentional consumption and intoxication involving both adults and children have been reported due to individuals mistaking edibles for regular treats. Edibles should be clearly labeled and stored out of the reach of young children.2 Some children who had accidental exposure to candies containing THC required ED treatment or hospital admission. Children generally had more severe symptoms than the adults and needed to stay in the hospital longer.
  • Research has shown some correlation between THC intoxication and motor vehicle crashes.1
  • THC is stored in fat cells and is slowly released into the body over time. Because of this, the CDC recommends that people who are pregnant or breastfeeding abstain from any type of cannabis use. Although no definitive data show that THC can be passed from breastmilk to child, more research is needed in this area.10
  • The CDC recommends that patients discuss with their doctor whether or not it is safe to use any form of cannabis with their medication regimen.10
  • Avoid drinking alcohol or other drug use while partaking in edibles, as this can increase the risk of intoxication.10
  • Be aware of label inaccuracy that can potentially lead to overdosing.


1. National Academies of Sciences, Engineering, and Medicine (NASEM). The health effects of cannabis and cannabinoids: the current state of evidence and recommendations for research. The National Academies Press. doi:10.17226/24625. 2017.
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3. Smart R, Pacula RL. Early evidence of the impact of cannabis legalization on cannabis use, cannabis use disorder, and the use of other substances: findings from state policy evaluations. Am J Drug Alcohol Abuse. 2019;45(6):644–663. doi:10.1080/00952990.2019.1669626.
4. Department of Justice/Drug Enforcement Administration. Drug Face Sheet
5. Daniller A. Two-thirds of Americans support marijuana legalization. Pew Research Center. 2020.
6. Monte AA, Zane RD, Heard KJ. The implications of marijuana legalization in Colorado. JAMA. 2015;313(3):241–242. doi:10.1001/jama.2014.17057.
7. Vandrey R, Raber JC, Raber ME, Douglass B, Miller C, Bonn-Miller MO. Cannabinoid dose and label accuracy in edible medical cannabis products. JAMA. 2015;313(24):2491–2493. doi:10.1001/jama.2015.6613.
8. Patel J, Marwaha R. Cannabis use disorder. StatPearls [Internet]. 2021.
9. Turner AR, Spurling BC, Agrawal S. Marijuana Toxicity. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-.
10. Centers for Disease Control and Prevention. Marijuana and public health. 2021.
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