Poison Center Calls Spike After Medical Marijuana Legalized

Megan Brooks

August 20, 2019

After Massachusetts legalized medical marijuana in 2012, cannabis-related calls to a poison control center involving children and teens doubled — and edible pot products are a particular concern, researchers say.

The increase in calls to the Regional Center for Poison Control and Prevention (RPC) at Boston Children's Hospital happened despite legislative mandates for childproof packaging and warning labels, and before the recreational use of marijuana was legalized for adults.

States liberalizing marijuana policies "should consider strengthening regulations to prevent unintentional exposure among young children and enhancing efforts to prevent use by teenagers, with particular attention to edible cannabis products and concentrated extracts," Jennifer Whitehill, PhD, and colleagues from University of Massachusetts Amherst, write.

The study was published online August 16 in JAMA Network Open.

140% Jump in Calls

The researchers reviewed the RPC data from 2009 through 2016 — 4 years before and 4 years after medical marijuana was legalized in Massachusetts.

During the 8-year study period, the poison control center received 218 calls related to cannabis exposure in children and teens aged 0 to 19, representing 0.15% of all poison control calls in this age group for the study period.

"While we're pleased to see that the incidence is relatively low, we feel these cases are preventable, and the issue needs to be on the radar of policymakers and parents, particularly now that dispensaries are open for adult-use sales," Whitehill said in a statement.

RPC calls related to cannabis exposure in children and teens jumped 140% during the study period, from 0.4 per 100,000 population before medical marijuana was legalized to 1.1 per 100,000 population after legalization. Most of the calls involved teenagers aged 15 to 19 years (178 calls, 81.7%).

A little more than a quarter of the exposure cases were reported as unintentional, with 19.4% of calls involving children from infancy through age 4.

The study also showed a statistically significant increase in RPC calls involving exposure to edible products following medical marijuana legalization in young children aged 0 to 4 and teens aged 15 to 19 years.

"This finding is concerning considering recent evidence regarding associations between edible and concentrated cannabis and acute psychiatric and emergency department visits," the investigators write.

A recent study from Colorado, reported by Medscape Medical News, showed that the number of cannabis-associated emergency department visits rose sharply after marijuana was legalized in the state, and a disproportionate number involved edibles.

"Front Side of the Curve"

Commenting on the study for Medscape Medical News, Robert Bassett, DO, associate medical director, The Poison Control Center at Children's Hospital of Philadelphia, noted that access to marijuana is growing exponentially.

"So it's not surprising that we are seeing an increase in usage and subsequent complications from usage both intentional and unintentional," said Bassett, who was not involved with the research.

He is also concerned about edible products. "Access to edibles, in particular, pose a unique problem that we've never dealt with before because you can get excessive amounts of concentrated THC, the active ingredient in marijuana," he said.

"I think we are just on the front side of the curve figuring out the full spectrum of toxicity of these products," Bassett said.

He added that it is easy to get "dangerously high toxic levels" of THC unintentionally because of the change in delivery mechanism with edibles.

"That's true for the 3-year-old who sees a brownie or gummy bear and puts it in their mouth and also for recreational users who don't have a sense of their tolerance or how to dose these products," said Bassett.

"There is a big debate whether an overdose of marijuana can be fatal; but if you take too much of anything there is some dose that can be fatal, even if you drink too much water or have too high a concentration of oxygen," he added.

The study was partially supported by the Massachusetts Department of Public Health. Whitehill and Bassett have reported no relevant financial relationships.

JAMA Netw Open. Published online August 16, 2019. Full article

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