At which dose does cannabis become toxic to kids?

Ingestion of tetrahydrocannabinol (THC) from edible cannabis at ≥1.7 mg/kg can lead to significant toxicity in young children, according to a study.

For the study, researchers reviewed the medical records of 80 children aged <6 years (median 2.9 years) who presented with edible cannabis ingestions of known THC dose within a paediatric hospital network.

Cannabis toxicity was deemed severe if the children showed severe cardiovascular (bradycardia, tachycardia/hypotension requiring vasopressors or intravenous fluids, other dysrhythmias), respiratory (respiratory failure, apnoea, requiring oxygen supplementation), or neurologic (seizure, myoclonus, unresponsiveness, responsiveness to painful stimulation only, requiring intubation or sedation) effects. Prolonged toxicity was defined as exceeding 6 hours to return to baseline from the time of ingestion.

The median THC ingestion in the sample was 2.1 mg/kg. Of the children, 46 percent had severe toxicity and 74 percent had prolonged toxicity. Multivariable logistic regression analysis showed that THC dose was significantly associated with severe (adjusted odds ratio [aOR], 2.9, 95 percent confidence interval [CI], 1.8–4.7) and prolonged toxicity (aOR, 3.2, 95 percent CI, 1.6–6.5). Age and sex showed no association with toxicity.

At a level of ≥1.7 mg/kg, THC dose predicted severe toxicity with an area under the curve (AUC) of 92.9 percent and a sensitivity of 97.3 percent, as well as prolonged toxicity with an AUC of 87.3 percent and a sensitivity of 75.4 percent.

In light of the findings, the threshold of 1.7 mg/kg of THC may be used to guide medical management and preventive regulations.