"One of the problems is people become very impatient," Bronstein said. "They eat a brownie or a chocolate chip cookie and they get no effect, so then they stack the doses, and all the sudden, they get an extreme effect that they weren't expecting."
Last year, the poison center run by Bronstein received 126 calls concerning adverse reactions to marijuana. So far this year — after pot sales became legal on Jan. 1 — the center has gotten 65 calls. Bronstein attributed the spike to the higher concentrations of THC in marijuana that has become available.
Although millions of Americans have used pot without becoming violent, Bronstein said such behavior is possible depending on the type of hallucinations a user experiences. Toxicologists say genetic makeup, health issues and other factors also can make a difference.
"With these products, everybody is inexperienced," Bronstein said. "It's the first time people have been able to buy it in a store. People need to be respectful of these products."