A new study has found that patients' reasons for visiting emergency rooms are different for edible marijuana than they are for the inhaled form and that the visits are disproportionately high for the number of edible products that are sold.
“That type of discrepancy is not something that we would tolerate in any of our food or any other type of medication, so I don’t think we should tolerate it in a drug that has killed people,” Dr. Andrew Monte, a toxicologist and emergency medicine physician at the UCHealth University of Colorado Hospital who led the study, told ABC News.
Marijuana use is widespread in the U.S., with about 7.5 percent of Americans over the age of 12 using it at any given time. Colorado legalized marijuana in 2014 and is one of 10 states — plus the District of Columbia — to do so.
Edible and inhaled marijuana share the same active ingredient: tetrahydrocannabinol, or THC for short. The inhaled form is more commonly used and has been associated with long-term lung damage. Edibles bypass the lungs entirely as the drug is mixed into various foods, such as brownies, gummies, drinks, cookies, granola and even popcorn. The downsides to edible marijuana have not been well studied.
For the most recent study, Monte and his team of researchers at the University of Colorado looked at 450,000 emergency room visits between 2014 and 2016. Edible marijuana made up a tiny fraction (0.32 percent) of Colorado sales, but accounted for more than 10 percent of emergency room visits — more than 30 times the rate of its sales.
The team found drastic differences in the symptoms that emergency room patients reported for smoked marijuana versus edible, too. Whereas inhaled marijuana brought people to the emergency room for upset stomachs, nausea and vomiting, patients who consumed edible marijuana were more likely to report psychiatric problems, such as psychosis and panic attacks, as well as cardiovascular issues like abnormal heart rhythms and heart attacks.
Monte said the difference in how our bodies process edible and inhaled marijuana might be to blame. The effects of edible marijuana, for example, don't begin to kick in until 30 minutes after ingestion, peaking two to three hours later. On the other hand, inhaled marijuana takes effect immediately.
Because people may not feel high as quickly, they may eat more and accidentally consume more THC than they intended.
Edible marijuana also stays in the body longer. Compared to inhaled marijuana, which peaks within 30 minutes and then fades away, edible marijuana stays in the system for eight to 12 hours. The longer someone feels ill, the more likely they are to end up in an emergency room.
Part of the danger of edible marijuana may lie in its packaging, which isn't always clear about dosing. Children are notorious for accidentally eating marijuana that looks like a treat, such as cookies or gummies. The same can happen to adults, who might also mix their marijuana with alcohol, compounding the drug’s effects.
“Many people use cannabis safely and it’s not a problem,” Monte said. “We’re not trying to demonize cannabis overall. But we also need to educate patients about safe use.”
For first-time users, Monte recommended starting at a very low dose — just 5 milligrams of the drug — and waiting at least four hours for its effects to kick in. For established users, he advises not to mix marijuana with sedatives, which may include alcohol and other medications. After taking edible marijuana, people should wait six hours before driving.
Dr. Leila Haghighat is an internal medicine resident from Yale New Haven Hospital who also works with the ABC News Medical Unit.