Feb. 13, 2013 -- Kidney damage is now among the growing list of serious health effects associated with using synthetic marijuana.
Also known as Spice, Spice Gold, and K2, synthetic marijuana has been marketed as various herbal mixtures and sold as incense, bath additives, and air fresheners. They contain synthetic cannabinoid, which mimics the effects of the natural ingredient in marijuana that causes a high.
A study at the University of Alabama, Birmingham, involved four previously healthy young men who developed short-term kidney damage, called acute kidney injury. All had used synthetic marijuana.
Three of the men also had an abnormally small amount of urine, and the fourth had a decrease in blood flow to the kidney. Three underwent a test that showed a condition called acute tubular necrosis. Left untreated, this can cause the kidneys to shut down.
All four recovered their kidney function, and none required dialysis.
In the study, researchers note a "dramatic increase" in the use of synthetic marijuana products in the past five years. The relatively low cost ($20 per gram) and the fact that they don’t show up on routine drug tests are cited as the main reasons for their growing popularity.
In the first half of 2010 there were 567 cases of synthetic marijuana use reported by U.S. poison control centers in 41 states, compared to 13 cases in 2009.
The researchers also note that use is growing despite laws banning these products in about 40 states. "This is partly because new synthetic preparations that are not covered by legislation continue to be made and are available on the streets sometimes days after the legislation against prior preparations is introduced," the researchers write.
Synthetic marijuana is typically smoked, but it can also be inhaled and ingested.
The products often include several additives. The researchers write that it is likely that an additive, rather than the synthetic cannabinoid, caused the acute kidney injury.
The study will be published in the March issue of the Clinical Journal of the American Society of Nephrology.