Deaths from using synthetic marijuana, or spice, have tripled so far this year and the number of emergency calls to US poison centers have soared, officials said Thursday.
From January until May, 15 people were reported dead from synthetic cannabinoid use, up from five during the same period in 2014, said the US Centers for Disease Control and Prevention.
During those months, US poison centers in 48 of 50 states reported receiving 3,572 calls related to synthetic cannabinoid use, a 229 percent increase over the 1,085 calls received during the same January through May period in 2014.
Nearly half of those calls (1,501) were made in April alone.
The findings suggest a need for "enhanced efforts to remove these products from the market," the CDC said in a statement.
The products are made with psychoactive chemicals that are sprayed onto plant material, which is then smoked or ingested.
Synthetic marijuana products are known by names such as spice, K2, black mamba, and crazy clown, and are sold in retail stores and online.
The most common symptoms reported to poison control centers were agitation, fast heart rate, drowsiness or lethargy, vomiting and confusion.