More people are visiting the ER after consuming marijuana, and edibles induce negative reactions at higher rates, according to researchers at the University of Colorado School of Medicine.
Users who smoke marijuana can still end up at the hospital, mostly from cannabis hyperemesis syndrome, which is defined by persistent nausea and vomiting.
But edibles can cause severe psychiatric effects and heart problems, said Dr. Andrew Monte, an emergency medicine and toxicology specialist at UC Health. Monte published the findings, which tracked nearly 10,000 cannabis-related ER visits between 2012 and 2016.
The overall number of visits during that time increased three fold, but Monte notes, so did overall trips to the ER. More notable is the fact that cases due to edible consumption were 33 times higher than anticipated. While they constitute fewer visits, edible sales are a far smaller share of the market than smoking products.
The reasons why aren't clear.
"To be perfectly frank with you, nobody really totally knows," Monte said.
Monte's original hypothesis, that the later onset of edibles caused people to take an unsafely high dose, wasn't held up by data. Now he's guessing that the length of symptoms may be a factor, that users only get more anxious as time goes on, like a feedback loop.
While patients with symptoms induced by marijuana are usually discharged quickly, Monte said they shouldn't be easily dismissed.
"They are severe events, so we would always recommend going to the ER, especially with psychosis and chest pain," he said.
Monte believes the most important step is simply education, and pushing back at the idea that marijuana is 100 percent safe for all people.
"Many thousands of people use cannabis safely. We need to understand and respect that," Monte said. "But we also know that it’s not completely safe, and we need to understand what those risks are. If people are going to use, they need to understand what those risks are and when it’s pertinent to them to go to the emergency department."
Looking forward, however, Monte questions if edibles should always be sold recreationally as there are now.
"I think that we need to take a real hard look as to whether or not edible agents are appropriate for the recreational marketplace," he said. "Clearly there’s a role for edibles for medicinal purposes for some conditions, but I’m not sure if that time course about when people get high and the increased risk of adverse drug effects actually makes sense in the recreational marketplace."