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Ask a Doctor is a series of physician-authored columns offering insights and advice on common health topics. It is not a substitute for seeking medical care.
In many Canadian households, cannabis has become a routine part of life. For some, it’s a way to unwind after work, while others use it for chronic pain or insomnia. With access increasing since Canada legalized cannabis in 2018, formulations have also expanded, with many cannabis products now mimicking everyday treats. This is one reason that emergency physicians like myself are seeing a rise in pediatric cannabis exposures. Here are some things parents should know about cannabis poisonings.
Why we’re seeing more cannabis-related emergencies
Edible cannabis products, such as gummies, chocolates, cookies and beverages, have become a leading cause of accidental poisonings in young children. One Canadian study published in 2022 found that in provinces where edibles were legal, the hospitalization rate for cannabis poisoning in children under 10 was 7.5 times as high as before legalization. Many of these products look almost identical to ordinary candy or baked treats. A young child doesn’t know the difference.
What symptoms to watch for
I’ve cared for many toddlers who seemed normal initially after ingestion only to become extremely sleepy a couple of hours later. Effects of cannabis ingestion can take anywhere from 30 minutes to three hours to develop – a delay that can create a false sense of security. In addition, symptoms often end up lasting much longer than people expect.
The most common symptom is excessive sleepiness. This can include difficulty to waking, appearing floppy or having trouble walking. Patients can also develop a fast heart rate or seem confused. In the most severe cases, breathing can become depressed.
Thankfully, most children recover fully with supportive care, including observation or receiving IV fluids in the emergency department. However, some do require admission to hospital, intensive care or even breathing support while the drug wears off.
An important note is that the amount of THC (delta-9-tetrahydrocannabinol), the main psychoactive chemical in cannabis, matters. A modest amount to an adult can represent a large dose for a toddler. An entire package of cannabis gummies can cause significant illness in a young child.
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Why teens end up in the emergency department
While young children present with accidental overdoses and predominant effects on breathing and level of consciousness, teens tend to present differently. More commonly, they’re intentionally using cannabis but underestimating its potency, particularly with edibles. A common mistake is assuming that an entire edible package is a single serving when, in reality, one package can contain multiple servings. This can lead to severe anxiety, panic attacks, paranoia and, in some cases, hallucinations or psychosis.
I’ve seen teenagers arrive in the emergency department terrified, convinced people were trying to harm them or unable to distinguish what was real from what wasn’t.
While these episodes often improve as the drug wears off, they shouldn’t be dismissed as an insignificant event. Adolescence is known to be a particularly vulnerable time for the developing brain. Research continues to show associations between regular cannabis use and problems with memory, attention and executive functioning. Further, studies have shown that cannabis use among adolescents is associated with increased risk of psychiatric disorders in adolescence and young adulthood.
Another condition that I’m starting to see more frequently among teens is cannabis hyperemesis syndrome. CHS is different from cannabis poisoning. It is a condition linked to chronic cannabis use that often causes repeated episodes of severe nausea, vomiting and stomach pain. While I have been seeing this condition for years in adults, younger patients are now coming to the ER exhibiting signs. While symptoms may temporarily improve with hot showers or baths, they can be unrelenting, and patients require many IV medications and fluids to manage the condition.
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When to seek medical care
If you think a young child has consumed cannabis, it’s important not to wait for symptoms to appear. Call your local poison centre immediately for advice, even if the child seems completely fine.
Go to the nearest emergency department right away or call 911 if the child is difficult to wake, has trouble breathing, has a seizure or becomes unresponsive, or if you’re worried they’re getting worse.
For older children and teenagers, seek urgent medical care if they develop severe panic, hallucinations, paranoia, persistent vomiting, suicidal thoughts or significant impairment that makes it difficult to stay safe.
How parents can reduce the risk
If you keep cannabis in your home, store it the same way you would prescription medications or household chemicals: locked up, out of sight and out of reach of children. Don’t leave edibles on a kitchen counter, on a bedside table or in a purse where curious hands can find them. Be aware of products brought into your home by visitors as well; this is a more common source of accidental ingestion than you might think.
Just as importantly, talk to teenagers honestly. Many assume cannabis is low risk because it’s legal. But legal doesn’t mean harmless. Explain that edible products can take hours to work, that potency varies widely and that taking more because “nothing is happening yet” is one of the most common reasons young people end up in the emergency department.
A locked cupboard and an honest conversation may prevent your next visit to the emergency department.
Dr. Shazma Mithani is an emergency physician working with adult and pediatric patients in Edmonton. She is actively involved with the Canadian Medical Association and the Alberta Medical Association, and is also co-host of the Doc Talk Podcast.