PORTLAND-- A form of synthetic marijuana known as "spice" has caused at least a half-dozen cases of sudden kidney failure in Oregon and Southwest Washington since May, the Oregon Health Authority reported Friday.
The agency said experts are analyzing samples to determine what toxin is causing problems. It has also asked doctors across the region to report cases of kidney failure that might be linked to the drug.
"This is not just a bad trip," said Gary Schnabel, executive director of the Oregon Board of Pharmacy, which voted to ban the sale and possession of synthetic cannabis products last year. "We are talking about your kidneys, and you only have two of them."
The six patients requiring hospitalization were from the Portland, Salem and Roseburg areas, as well as Vancouver. The most recent case occurred in late September.
Five of the patients were 18 or younger, and all were male. Though they have been discharged, they remain at heightened risk for kidney problems later in life.
Spice, which is typically smoked, is a mixture of plant material sprayed with a designer drug similar to THC, the main psychoactive component of cannabis. It's marketed under street names such as "K2," "herbal incense" and "potpourri."
A University of Michigan study found that 11.4 percent of high school seniors reported using synthetic marijuana in the past year. There is no such statistic for Oregon.
The manufacturers are generally overseas and unknown, and there are often no ingredients on the package. The Oregon patients bought the illegal drug over-the-counter at places such as convenience stores, gas stations and tobacco shops, said Dr. Katrina Hedberg, the state epidemiologist.
"It's very hard to regulate something that's being sold as potpourri," Hedberg said. "Doesn't that sound like something you put in your bathroom that smells nice?"
"It's a clear effort to circumvent the law," she added. "The people who are buying it know what it's intended use is -- while not explicit."
But law enforcement has taken notice. A federal grand jury in Idaho indicted five people in July on charges they conspired to distribute synthetic marijuana products. As part of the investigation, 14 search warrants were issued at businesses in Idaho, Oregon and Southwest Washington.
Authorities in Wyoming arrested three people in March after several users in Casper were hospitalized with kidney failure.
Poison centers responded to 3,200 calls related to synthetic marijuana or "bath salts" in 2010 and that number soared to more than 13,000 last year, said Jodie Underwood, Drug Enforcement Administration agent in Seattle.
"A teenager thinks it safe because it's being sold in a gas station," Underwood said. "And these products are not for human consumption."