A report in this week's journal pediatrics says poison control centers got 4,500 calls related to synthetic pot in just the past year.
Known under brand names like K-2, Spice, Mister Smiley and Blaze, synthetic marijuana is a legal product sold in places like gas stations and convenience stores.
Doctors say the drug is difficult to detect, because it does not show up on routine drug tests. Experts say synthetic marijuana could cause memory loss and psychosis.
