THC Dose of Edible Cannabis Tied to Degree of Toxicity in Young Kids

— Researchers note possible thresholds for medical decisions and marijuana regulations

A photo of a little boy looking at gummy candies on a countertop.

The tetrahydrocannabinol (THC) dose of edible cannabis correlated to the degree of toxicity in children under 6 years, a retrospective review showed.

Among 80 kids with a median age of 2.9 years, THC weight-based dose was a significant predictor of severe toxicity (adjusted OR 2.9, 95% CI 1.8-4.7) and prolonged toxicity (aOR 3.2, 95% CI 1.6-6.5), while patient age and sex were not, reported Lesley Pepin, MD, of Denver Health and Hospital Authority, and colleagues.

The area under the curve (AUC) was 92.9% for severe toxicity and 87.3% for prolonged toxicity, they noted in Pediatrics.

THC ingestions of at least 1.7 mg/kg can predict severe toxicity, with a sensitivity of 97.3%, and prolonged toxicity, with a sensitivity of 75.4%, they said.

"Ultimately, we propose that exposures exceeding 1.7 mg/kg of THC would benefit from being managed where pediatric services and prolonged observation or admission capabilities are available," Pepin and colleagues wrote. "Transfer to a tertiary facility could be avoided in children with smaller ingestions who do not require interventions beyond observation."

"Home observation through poison center guidance may require a larger safety margin and likely widespread improvement in cannabis regulations," they added.

Ingestion is the most common route of cannabis exposure in young children, the authors noted. Edible cannabis products are often sold in forms that may be difficult to distinguish from non-cannabis items, and include gummies, chocolate, candy, and baked goods.

A rise in overall cannabis exposures in young children from 2017 through 2021 was largely due to ingesting edible cannabis products, "during which time a higher proportion of children required hospital admission, which suggests an increase in toxicity from these exposures," Pepin and colleagues wrote, noting that cannabis edibles "pose a heightened risk in this age group."

"Based on our bedside experience managing these cases as a toxicology service, we were surprised by the THC dose that predicts more severe and prolonged effects from cannabis," Pepin told MedPage Today in an email. "The 1.7 mg/kg threshold was lower than we expected."

"In Colorado, where we performed the study, the maximum THC content for a single recreational gummy edible is 10 mg," she noted. "A 3-year-old in the 50th percentile for weight may reach the 1.7 mg/kg threshold with only 2.5 edible gummies."

"It is important to note that regulations around cannabis products are very state/region dependent," she added. "Medicinal products can also have their own regulations. If a product was intended for medicinal use, a single edible may have a much higher THC content. If a product was purchased online or illegally, there is also a chance the labeled THC dose is unreliable."

Among the 80 cases of edible cannabis ingestion, 43% of patients did not require medical interventions; 76% of these patients ingested 2 mg/kg of THC or less. However, severe toxicity was present in 46% of cases. The median THC dose was 5.4 mg/kg in these patients, and the median duration of symptoms was 20.3 hours. Gummy edibles were responsible for 57% of these cases.

In 88% of cases, the child obtained a cannabis edible from home. In six cases, an edible was mistaken for a non-cannabis product and given to the child, and in two cases, there was co-exposure to another medication.

The median length of stay was 6.1 hours for patients who were discharged from the emergency department, and 24 hours for patients who were admitted.

Sedation or lethargy was the most commonly reported symptom, affecting 85% of patients. No patients received gastrointestinal decontamination.

Timing of signs or symptoms was estimated in 83% of 72 symptomatic patients, with a median onset time of 1 hour.

Neurologic effects accounted for 76% of presentations among patients with severe toxicity. Sixty-five percent of patients had more than one system that met the severe toxicity definition, and the remaining 13 patients had supplemental oxygen requirements (four), hypotension requiring intravenous fluids (two), and severe neurologic effects (seven).

Median onset to severe toxicity was estimated in 84% of cases, and was within 2.3 hours. Seventy-four percent of patients demonstrated prolonged toxicity, with a median THC dose of 3.7 mg/kg.

"The THC dose ingested can be used to risk stratify patients in this age group, with ingestions exceeding 1.7 mg/kg being more likely to develop severe and prolonged toxicity," Pepin and colleagues concluded.

"This threshold should be considered in both medical management decisions and development of marijuana regulations," they added.

Of 325 pediatric hospital network encounters for cannabis exposures in kids under age 6 from January 2015 through October 2022, 80 patients met inclusion criteria for this study. Median patient age was 2.9 years, and the group was split evenly by sex. THC dose ranged from 0.2 mg/kg to 69.1 mg/kg, with a median dose of 2.1 mg/kg. Of the edible cannabis types, 61% were gummies and 23% were chocolate.

The study population reflected the most common pediatric age group that unintentionally ingests edibles, but excluded other age groups, Pepin and team noted, which was a limitation.

Additionally, there may have been errors in parent or guardian reporting, and though there are quality mandates in place for THC dose accuracy, the FDA has not approved federal testing requirements or standards, they added.

Furthermore, not all patients had confirmatory testing to prove cannabis exposure, and the retrospective study design was limited by the completeness of medical chart documentation.

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    Jennifer Henderson joined MedPage Today as an enterprise and investigative writer in Jan. 2021. She has covered the healthcare industry in NYC, life sciences and the business of law, among other areas.


This study had no external funding.

Pepin had no disclosures. A co-author disclosed relationships with the Cannabis Research and Policy Project through the University of Colorado School of Public Health and UpToDate, in addition to being a co-investigator/consultant for NIH-funded work on assessing cannabis-impaired driving.

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Source Reference: Pepin LC, et al "Toxic tetrahydrocannabinol (THC) dose in pediatric cannabis edible ingestions" Pediatrics 2023; DOI: 10.1542/peds.2023-061374.