05-06-2019 Is it Just A Little Pot? What is the Impact of Edible Marijuana on Children?

Toxicology Question of the Week

May 6, 2019

Is it Just A Little Pot? What is the Impact of Edible Marijuana on Children?

Marijuana is not new in the world of toxicology, but the rise of medical and recreational marijuana legalization brings with it a new wave of consequences, particularly for children.

THC, or delta-9-tetrahydrocannabinol, is the active ingredient in marijuana. It binds anandamide receptors in the brain, causing a mixture of stimulant, sedative and hallucinogenic effects. The THC contents of edible forms of marijuana vary substantially, with no federal oversight to its contents, labeling, or packaging. Commercially-produced low dose products may contain 1-2.5 mg of THC per dose, with THC increasing to 50 to 100 mg per dose in some formulations.

Not only is edible marijuana potent, it is extremely attractive to children. Many formulations of edible marijuana are indistinguishable from traditional food products, particularly in candy and cookie formulations. Furthermore, children do not adhere to dosing recommendations, often ingesting larger than recommended doses as they discover these sweet-tasting snacks.


The threat posed to children by edible marijuana is not only theoretical, it is proven by studies in states where marijuana is legal. A study of Poison Center calls between 2005 and 2011 found an increase in call rates for marijuana exposures in children less than 9 years of age of 30% per year for states with legalization of marijuana. Roughly half of all 985 exposures documented occurred in the 14 states with legalization, but exposures were still very much present in states where marijuana is illegal.

Ingestion itself is not benign, with children presenting with lethargy, ataxia, tachycardia, hypotonia, and mydriasis. As these symptoms are not specific to ingestion, children with unidentified marijuana ingestion may require substantial and invasive medical work-up for traumatic and infectious etiologies of their symptoms. Even once marijuana ingestion is identified, altered mental status and respiratory depression may be significant, with one meta-analysis of 144 children with marijuana ingestions demonstrating a PICU admission rate of 18% and intubation rate of 6%. Peak concentrations in adult studies typically occur 2-3 hours following ingestion, with duration of clinical symptoms in children routinely lasting up to 24 hours, but sometimes longer.

While legislation aimed at packaging warnings and child-resistant packaging is an important step in minimizing risks to children, it is will not eliminate risks to children, particularly in those who cannot read or do not speak in English. In states without legalization, such as Tennessee, these products are not likely to be kept in their original packaging, further increasing the risk to children.

Clinicians should be aware of the risk posed by edible marijuana in children and keep it in their differential for the undifferentiated patient with lethargy and ataxia.

This question was prepared by: Laura Satori, MD, Pediatric Emergency Medicine Fellow VUMC


  1. Wang GS, Roosevelt G, Le Lait MC, Martinez EM, Bucher-Bartelson B, Bronstein AC, Heard K. Association of Unintentional Pediatric Exposure With Decriminalization of Marijuana in the United States. Annals of Emergency Medicine. 2014; 63(6): 684-689.
  2. Richards JR, Smith NE, Moulin AK. Unintentional Cannabis Ingestion in Children: A Systematic Review. The Journal of Pediatrics. 2017; 190: 142-152.
  3. Vandrey R, Herrmann ES, Mitchell JM, Bigelow GE, Flegel R, LoDico C,Cone EJ. Pharmacokinetic Profile of Oral Cannabis in Humans: Blood and Oral Fluid Disposition and Relation to Pharmacodynamic Outcomes. Journal of Analytical Toxicology. 2017;41:83-89.

We have recently seen a child with altered mental status (AMS) from eating THC.  The problem is the urine drug screen (UDS) doesn’t help because the UDS can be positive for days after the ingestion and therefore may not be the cause of AMS.  In most cases, a workup for the altered mental status (depending on the degree of the alteration) is required. -ds

I am interested in any questions you would like answered in the Question of the Week.  Please email me with any suggestion at donna.seger@vumc.org.

Donna Seger, MD

Executive Director

Tennessee Poison Center


Poison Help Hotline: 1-800-222-1222