An herb and chemical blend dubbed K2 that is sold legally in the U.S. as incense but produces a marijuana-like high when smoked is landing a rising number of people in emergency rooms, doctors said.
The surge in calls to poison control centers across the country has spurred 10 states to ban K2 and other similar brands of so-called synthetic marijuana products.
It has also prompted public doctors who have treated patients who used K2 to issue health warnings.
"My first reaction to a product like this is 'buyer beware,'" said Anthony Scalzo, director of toxicology at Cardinal Glennon Children's Medical Center in St. Louis.
"You don't know exactly what is in the product, the relative doses in the product, and there is no quality assurance," he explained.
K2, defined by the Missouri Poison Center as a mix of herbs and spices that are sprayed with a psychoactive chemical, is likened to marijuana because the chemical compound produces a similar interaction with receptors in the brain.
Despite label warnings against consumption, smoking K2 has become a popular way to get high and pass drug screens. The product is sold online and at convenience stores and other outlets for roughly $30 to $40 for a 3-gram bag.
Users ranging from teens to adults in their 60s have suffered from agitation, anxiety, hypertension, vomiting and in some cases severe paranoia and hallucinations.
"These people come into an ER, they are extremely agitated," Scalzo said. "They feel like their heart will beat out of their chest."
The substance has also been linked to a suicide in Iowa and may have played a role in at least one other near-suicide, Scalzo said.
Scalzo, who also serves as the medical director for the Missouri Poison Center, said cases stemming from the use of K2 were considered rare just a year ago, when centers nationwide fielded just 13 related calls.
But with 766 cases already reported to poison control centers in 46 states and the District of Columbia during the first half of 2010, Scalzo fears "it may represent the tip of an iceberg."
The American Association of Poison Control Centers said Missouri, Indiana, Georgia, Utah and Texas have the highest use of K2.
Unlike marijuana, which has been heavily researched, little is known about whether the chemical compounds in K2.
Alabama, Louisiana, North Dakota, Tennessee and Kentucky were among the first 10 states that have already passed some form of a ban, according to data from the National Conference of State Legislatures.
Other states such as Nebraska are considering bans
"We just don't know what the long-term effects are and we need to address it," said Nebraska State Senator Beau McCoy, who intends to introduce a bill next term prohibiting both selling and possession of K2.
McCoy is trying to write an inclusive bill that broadly bans the ingredients of the chemical compounds sprayed on the dried herb mix, preventing an alteration in the chemical makeup of the spray that would allow the substance back on the market.
