Marijuana is the most commonly used recreational drug in the United States with an estimated 22 million people using it monthly based on 2015 data from the National Survey on Drug Use and Health.1 According to one large survey, rates of marijuana use among teens have increased as perceptions about risk have decreased.2 In the survey, more than 1 in 3 high school seniors endorsed using marijuana in the preceding year.2 Based on an analysis of the National Poison Data System, there is a documented association of unintentional pediatric exposures with legalization of marijuana in the United States.3 An additional factor contributing to the severity and risk of marijuana intoxication is that the potency of marijuana has significantly increased in the last few decades. In the 1980s, the percentage of delta9-tetrahydrocannabinol (THC) in recreational marijuana was 4% but it had increased to 12% by 2012.4 Emergency department (ED) visits for marijuana have increased for both adults and adolescents in recent years, with the fastest increase in rates observed in those age 12 to 17 years. Between 2004 and 2011, rates of ED visits for marijuana doubled in this age group.5
Mechanism of Action
Marijuana contains approximately 60 pharmacologically active cannabinoids.6 The two for which there is the most information are THC and cannabidiol (CBD). The importance and impact of the other active components in marijuana is mostly unknown. THC is the main psychoactive compound in marijuana and functions in a dose-dependent manner, affecting several different areas of the brain and spinal cord. By exerting antagonistic effects on the CB1 receptor, THC causes mood changes, perception alteration, disturbance of memory function, and impaired judgement.6 Contrary to popular notions, marijuana is an addictive substance, with 9% of those using it recreationally becoming addicted.7 Compared to other forms of consumption, smoking marijuana has the highest addictive potential due to rapid and efficient drug delivery to the brain.3 When ingested orally, the absorption is slow and a significant portion of THC is degraded in the stomach, with bioavailability of 10% to 20%. Peak concentration usually occurs within 1 to 2 hours but can take as long as 8 hours.6
Uses, Available Forms, and Risks
Marijuana can be consumed in a variety of ways, including vaporization, smoking, oral ingestion, as well as via transcutaneous, rectal, and vaginal routes. Its legalization in several states has led to increasing availability in edible forms such as as candy, baked goods (eg, cookies, brownies), and beverages. Synthetic forms of THC are available via prescription (nabilone and dronabinol). These forms of THC do not have the hallucinogenic properties of naturally occurring marijuana, and their approved uses include treatment of anorexia in patients with AIDS and treatment of nausea and vomiting caused by chemotherapy for patients with cancer.8
In young children, the most common place of ingestion is in the patient's home,9 with more than one-half of them consuming an edible form of marijuana.10 Edible products are particularly attractive to young children as they are often in the form of a food that is highly attractive such as cookies, brownies, or candies. The amount of THC in a single product can be variable and potentially high. In many instances, a single chocolate bar or brownie can contain 10 to 50 adult doses of THC and thus is extremely toxic for a child.11 The documented increasing THC percentage in marijuana in the last several years has been recognized as a factor in the increased incidence of serious ingestions (ie, those causing seizures or requiring intubation).9,12
As the amount of THC in marijuana products may be high, young children who ingest them are usually symptomatic. There is a direct relationship between the estimated milligrams of THC per kilogram of body weight ingested and the level of medical intervention needed.13 Most commonly, young children who generally are naïve to marijuana present with altered mental status.14 Parents often report that the lack of responsiveness happens suddenly, but it should be noted that symptom onset may happen 1 or 2 hours after ingestion.15 Children may become ataxic, somnolent, confused, and difficult to arouse.13 Seizures have been reported, and generalized hypotonia is not uncommon.12 Many become agitated and may vomit. Respiratory depression with a range of severity is possible, and in some instances it requires supportive intervention. Older children and adolescents may present with anxiety, dysphoria, ataxia, slurred speech, injected (ie, red) eyes, tachycardia, and increased respiratory rate.16
Supportive care is the first order of consideration, with initial attention to airway, breathing, and circulation. Cases of young children presenting in a coma requiring respiratory support are not unusual, so the ability to perform rapid sequence intubation should be assured.10 After stabilization of cardio-respiratory status, a broad evaluation for presenting symptoms should take place. Most commonly, an evaluation of altered mental status will be needed. Assessment includes bedside glucose measurement, electrolytes, complete blood count, toxicology screen, and computed tomography scan of the head. If the clinical picture is consistent with meningitis, a lumbar puncture should be considered.
A urine toxicology screen can identify cannabinoids and can be positive up to 30 days after ingestion by chronic users.16 A single ingestion in a nonuser typically results in a urine drug screen that will be positive only up to 72 hours.17 In any possible ingestion with diminished level of consciousness and respiratory depression, a dose of nalaxone can be given. Improvement after naloxone indicates possible opiate or clonidine toxicity but will not be effective for those with THC toxicity.18 Co-ingestion with other recreational drugs (eg, cocaine, phencyclidine) should also be considered, and a urine toxicology screen for drugs of abuse should reveal this.
Treatment is supportive and based on symptoms. Seizures should be treated with benzodiazepines, which are indicated for treatment of anxiety and dysphoria in older children as well. Reassurance and reduction of environmental stimulation/comfort measures are also useful in children with anxiety.
Use of activated charcoal is not recommended because symptoms are often delayed by 1 to 3 hours.18
The duration of symptoms after marijuana exposure can vary from 4 to 48 hours depending on the amount ingested.19 Hospital admission and observation in the ED should be guided by the severity of the symptoms. Social work evaluation to assess home safety and parental supervision is highly recommended.
Social Trends and Prevention
The number of states legalizing medicinal and recreation marijuana is growing. Nine states and the District of Columbia have legalized marijuana for recreational use in adults age 21 years and older, and medical marijuana is legal in an additional 30 states.20 Attitudes toward cannabis use and legalization have become more positive over time, with the latest Gallup poll finding 66% of Americans supporting legalization.21 As legal and attitudinal trends become more favorable and as retail accessibility of marijuana increases, THC-containing products will be found more frequently in homes with children. Because many of the forms of edible marijuana products are identical to common and attractive food products, their risk to small children is particularly great. Parents must understand the danger of all forms of marijuana, so education on safe storage is imperative. Parents should also have an appreciation for the toxic effects of edible marijuana on children and that toxicity can happen with small ingestion due to high THC levels in edible products.
Most states have regulations that require clear labeling on marijuana product packaging, including warnings to keep in its original packaging and out of reach of children. Yet, clearly this is not enough. The American Academy of Pediatrics advises storing marijuana products in locked locations or in child-resistant packaging, never consuming marijuana edibles in front of children, and talking to friends and family members about storage of their products.22,23 Using the example of Colorado child health providers, pediatricians can advocate for legislation that requires mandatory child-resistant packaging for recreational marijuana.3,24
- Substance Abuse and Mental Health Services Administration. Results from the 2015 national survey on drug use and health: detailed tables. http://www.samhsa.gov/data/sites/default/files/NSDUH-DetTabs-2015/NSDUH-DetTabs-2015/NSDUH-DetTabs-2015.htm. Accessed November 18, 2018.
- Johnston L, O'Malley P, Miech R, Bachman J, Schulenberg J. Monitoring the future: national survey results on drug use: 1975–2016: 2016 overview: key findings on adolescent drug use. http://www.monitoringthefuture.org/pubs/monographs/mtf-overview2016.pdf. Accessed November 18, 2018.
- Wang GS, Roosevelt G, Le Lait M, et al. Association of unintentional pediatric exposures with decriminalization of marijuana in the United States. Ann Emerg Med. 2014;63:684–689. doi:. doi:10.1016/j.annemergmed.2014.01.017 [CrossRef]
- El Sohly MA. Potency Monitoring Program. Quarterly Report No. 123—Reporting Period: 09/16/2013-12/15/2013. Oxford MS: University of Mississippi, National Center for Natural Products Research; 2014.
- Zhu H, Wu L. Trends and correlates of cannabis-involved emergency visits: 2004–2001. J Addict Med. 2016;10(6):429–436. doi:. doi:10.1097/ADM.0000000000000256 [CrossRef]
- Oberbarnscheidt T, Miller NS. Pharmacology of marijuana. J Addict Res Ther. 2016;S11:012. doi:10.4172/2155-6105.1000S11-012 [CrossRef].
- Hall W, Degenhardt L. Adverse health effects of non-medical cannabis use. Lancet. 2009;374(9698):1383–1391. doi:. doi:10.1016/S0140-6736(09)61037-0 [CrossRef]
- AbbVie Inc. Marinol. http://www.marinol.com. Accessed November 18, 2018.
- Claudet I, Mouvier M, Labadie M, et al. Unintentional cannabis intoxication in toddlers. Pediatrics. 2017;140(3):e20170017. doi:. doi:10.1542/peds.2017-0017 [CrossRef]
- Wang GS, Le Lait MC, Deakyne SJ, et al. Unintentional pediatric exposures to marijuana in Colorado, 2009–2015. JAMA Pediatr. 2016;170(9):e160971. doi:. doi:10.1001/jamapediatrics.2016.0971 [CrossRef]
- Barrus DG, Capogrossi KL, Cates SC, et al. Tasty THC: promises and challenges of cannabis edibles. Methods Rep RTI Press. 2016. doi:10.3768/rtipress.2016.op.0035.1611 [CrossRef].
- Claudet I, Le Breton M, Bréhin C, Franchitto N. A 10-year review of cannabis exposure in children under 3-years of age: do we need a more global approach?Eur J Pediatr. 2017;176(4):553–556. doi:. doi:10.1007/s00431-017-2872-5 [CrossRef]
- Heizer JW, Borgelt LM, Bashqoy F, Wang GS, Reiter PD. Marijuana misadventures in children: exploration of a dose-response relationship and summary of clinical effects and outcomes. Pediatr Emerg Care. 2018;34(7):457–462. doi:10.1097/PEC.0000000000000770 [CrossRef].
- Pelissier F, Claudet I, Pelissier-Alicot A, Franchitto N. Parental cannabis abuse and accidental intoxications in children: prevention by detecting neglectful situations and at-risk families. Pediatr Emerg Care. 2014;30:862–866. doi:. doi:10.1097/PEC.0000000000000288 [CrossRef]
- Murray D, Olson J, Lopez A. When the grass isn't greener: a case series of young children with accidental marijuana ingestion. CJEM. 2016;18(6):480–483. doi:. doi:10.1017/cem.2015.44 [CrossRef]
- Grotenhermen F. Pharmacokinetics and pharmacodynamics of cannabinoids. Clin Pharmacokinet. 2003;42(4):327–360. doi:. doi:10.2165/00003088-200342040-00003 [CrossRef]
- Hollister LE, Kanter SL. Laboratory verification of “heavy” and “light” users of cannabis. Drug Alcohol Depend. 1980;5(2):151–152. doi:. doi:10.1016/0376-8716(80)90192-1 [CrossRef]
- Wang GS. Cannabis (marijuana): acute intoxication. https://www.uptodate.com/contents/cannabis-marijuana-acute-intoxication/print. Accessed November 27, 2018.
- Atakan Z. Cannabis, a complex plant: different compounds and different effects on individuals. Ther Adv Psychopharmacol. 2012;2(6):241–254. doi:. doi:10.1177/2045125312457586 [CrossRef]
- Berke J. Here's where you can legally consume marijuana in the US in 2018. https://www.businessinsider.com/where-can-you-can-legally-smoke-weed-2018-1. Accessed November 18, 2018.
- McCarthy J. Two in three Americans now support legalizing marijuana. https://news.gallup.com/poll/243908/two-three-americans-support-legalizing-marijuana.aspx. Accessed November 18, 2018.
- Ryan SA, Ammerman SDCommittee on Substance Use and Prevention. Counseling parents and tends about marijuana use in the era of legalization of marijuana. Pediatrics. 2017;139(3):e20164069. doi:. doi:10.1542/peds.2016-4069 [CrossRef]
- American Academy of Pediatrics. Edible marijuana dangers: how parents can prevent pot poisoning. https://www.healthychildren.org/English/ages-stages/teen/substance-abuse/Pages/Edible-Marijuana-Dangers.aspx. Accessed November 18, 2018.
- Children's Hospital of Chicago. Marijuana safety policies supported by Children's Hospital Colorado. https://www.childrenscolorado.org/conditions-and-advice/marijuana-what-parents-need-to-know/marijuana-laws/bills-supported-by-children-s-colorado/. Accessed November 18, 2018.