By Keith Coffman
DENVER (Reuters) - Colorado authorities are investigating the deaths of three people and the hospitalization of 75 others who fell ill in recent weeks after possibly smoking synthetic marijuana popularly known by the street name "Spice," officials said on Friday.
The state health department said that since late August, hospitals in the Denver metropolitan area and in Colorado Springs have treated dozens of patients who may have ingested dangerous synthetic pot.
"Several individuals were in intensive care and three deaths are being investigated as possibly associated," a statement from the Colorado Department of Public Health and Environment said. It added that 75 patients were hospitalized but survived.
Colorado and Washington state last year became the first two U.S. states to legalize the adult recreational use of marijuana despite a federal ban on the drug, while the legality of synthetic versions of the drug in Colorado can vary depending on their ingredients.
The outbreak of illnesses possibly tied to synthetic pot indicates it may continue to be popular in some circles despite the newfound legality at the state level of its natural cousin.
Mason Tvert, a spokesman for the Marijuana Policy Project and a leading player in the push to legalize pot in Colorado, said some synthetic marijuana users may continue to opt for that drug because stores selling cannabis to the recreational market are not slated to open until 2014.
He added that users can be "steered toward these harmful substances" because it is easier to pass workplace drug tests after using synthetic pot than actual marijuana, since the chemicals in the designer drug are harder to detect.
MARKETED AS 'SAFE'
Synthetic marijuana products are marketed and sold as "safe" alternatives to marijuana, but they can cause psychotic effects such as extreme anxiety as well as reduce blood supply to the heart, according to the National Institute on Drug Abuse.
The products are made of dried plants, but their active ingredients are synthetic cannabinoid compounds, the institute said on its website.
Synthetic marijuana has been easy to buy in head shops, gas stations and over the Internet, and is the second most abused illegal substance by high school seniors behind marijuana, according to NIDA.
Synthetic marijuana is sold under several names, including Black Mamba, Monkey Spice, K2, Twilight and Herbal Incense, but no single product has been identified as the source for the reported illnesses or fatalities, the health department said.
But certain forms of synthetic pot have been outlawed in a number of states in recent years. Manufacturers of the drug have attempted to evade legal restrictions by substituting different chemicals in their mixtures, according to NIDA.
Synthetic marijuana made from certain chemical compounds is illegal in Colorado under a bill approved in 2011. Also, the U.S. Drug Enforcement Administration has designated five active compounds frequently found in synthetic pot mixtures as controlled substances.
But authorities have not yet determined what chemicals were responsible for the recent cluster of illnesses, said Carolyn Tyler, spokeswoman for the Colorado Attorney General's Office.
"We still need to look at what the chemical compound is," she said, adding that lab work will be required in this case.
(Editing by Alex Dobuzinskis, Cynthia Johnston and Tim Dobbyn)