Elizabeth Prabhu, MD
Pediatric emergency medicine fellow
Marijuana is the most cultivated, trafficked and abused illicit substance worldwide and its use is increasing among youth in the United States. An estimated 2.5% of the world population use cannabis, which is about 150 million people. Between 10-20% of middle school and high school students admit to using marijuana when surveyed anonymously about their use. Some states in the US have experienced changes to the marijuana laws, which may lead to more marijuana exposures in the pediatric and adolescent population.
Different types and formulations of marijuana exist. Cannabis sativa refers to the dried flower of the marijuana plant, which is the most commonly used recreationally. Over 60 cannabinoids exist and Delta-9-tetrahydrocannabinol (THC) is the most psychoactive and most responsible for the symptoms of intoxication. Marijuana can be smoked, vaporized, or made into oils/tinctures in highly concentrated forms.
Another popular form of marijuana use is ingested cannabis mixed into food products, such as cookies, cakes and candies. These food products made with cannabis for recreational use are commonly referred to as “edibles”. Some examples of products sold are “mile high bar” or the “mile higher bar”, “mountain high suckers” or “karma candy”. In regions where marijuana use is legal ingested forms are popular and may pose a risk of unintentional ingestion by children or excessive ingestion in adults.
Marijuana affects are from cannabinoid receptors CB1 and CB2 in the central nervous system or located peripherally, causing the inhibition of several neurotransmitters, such as GABA and dopamine. These neurotransmitters control movement, cognition, motivation and affect. Acute toxicity occurs when more than 7.5mg/mg2 of THC is inhaled or when 5-300mg is ingested.
Toxicity in children usually occurs after exploratory ingestion of marijuana intended for adult use. Clinical manifestations in children who have inhaled a toxic dose of marijuana include nausea, postural hypotension, delirium, panic attacks and myoclonic jerking. Children who have ingested a toxic amount usually present with sleepiness, behavioral change, ataxia, hyperkinesis, and even respiratory depression or coma.
Laws across the United states have been changing over the past two decades, in regards to marijuana legalization. Thus far, 20 states have legalized marijuana use for medical conditions. And since 2012, Colorado and Washington have legalized marijuana for recreational use for adults 21 years and older. The impact of the legalization of marijuana use has not fully been realized. A review of medical marijuana laws in 50 states showed that there is a higher odds of marijuana use where medical marijuana is legal. Potency of THC in marijuana has risen over the past 2 decades and has also increased since more states have legalized its use.
The full impact of legalizing marijuana in the US on pediatric marijuana exposures is yet to be known. A retrospective study done in the Children’s hospital of Colorado demonstrated an increase in the proportion of marijuana ingestions in patients 12 years old and younger after the legalization of medical marijuana. Out of the 14 patients in the cohort, 2 patients had severe enough respiratory depression to require PICU monitoring. The majority of the reported pediatric toxic ingestions of marijuana were from unintentional ingestion of edible products.
Marijuana use and potency has been increasing over the past two decades and use in the pediatric and adolescent population is climbing. Liberalization of marijuana laws may increase the number of pediatric exposures, so as an emergency medicine physician one should always keep marijuana toxicity on the differential. More studies are needed to study the potential effect of legal recreational marijuana in the pediatric population.