Despite dire warnings about the dangers of synthetic cannabinoids, popularly known by names such as K2, Spice, Black Mamba and Kronic, they continue to grow in popularity, NBC News reports.
On Tuesday, 33 people were rushed to the hospital in Brooklyn with symptoms that suggested an overdose on the drugs. New York City's health department told NBC New York there have been more than 6,000 K2-related emergency room visits and two confirmed deaths in New York City since 2015.
To get a better understanding of what K2 is and why the drug is so dangerous, NBC News spoke with Marilyn A. Huestis, a professor at the University of Maryland School of Medicine in Baltimore and former chief of chemistry and drug metabolism at the National Institute on Drug Abuse.
"They can destroy the kidneys so people may die or need to have dialysis and/or transplants," she said. "They can cause cardiovascular effects and can bring on heart attacks and strokes in the brain."