Some people may consider smoking synthetic marijuana be a more harmless alternative, but researchers are warning that it may take a toll on their kidneys.
Four case studies have linked the marijuana-alternative drug to kidney damage. The findings appeared in the March 2013 print edition of the Clinical Journal of the American Society of Nephrology.
"Cases of acute coronary syndrome associated with synthetic marijuana use have been reported, but our publication is the first to associate use with acute kidney injury," study co-author Dr. Gaurav Jain, assistant professor in the Division of Nephrology, said in a press release.
Synthetic marijuana is a designer drug that mimics the effects of pot. Study authors pointed out that its low price of about $20 a gram makes it appealing. It is sold under a variety of names including K2 and Spice. Usually made from a blend of different herbs, it is often sprayed with synthetic cannabinoid compounds.
Though first sold legally in gas stations starting in 2008 -- and labeled "not for human consumption" -- most of the active chemicals are now a DEA Schedule I drug. Synthetic marijuana is currently banned in 38 states, and the Food and Drug Administration has banned wholesale purchases as of 2012.
A December 2012 report by the Drug Abuse Warning Network (DAWN), a part of the Substance Abuse and Mental Health Services Administration (SAMHSA), revealed that 11,406 people went to the emergency room because of synthetic pot in 2010. Fifty-nine percent of the patients only had synthetic marijuana in their system, and 36 percent had consumed another substance as well. One-third of the patients were between the ages of 12 to 17, and another 35 percent were between 18 and 24. Seventy-eight percent were men.
Fitting the demographic of the typical synthetic marijuana user, the researchers looked at four different cases of previously healthy young men. They all went to a hospital within a nine-week period and had symptoms of nausea, vomiting and abdominal pain after using the drug. Three of the men had abnormally low urine levels, and a fourth had lower blood flow to the kidney. In addition, the biopsies of three of the subjects showed that they had kidney cell death, which can lead to kidney failure. However, the men were able to regain their kidney function and did not need dialysis.
Because the men were in the same area and had the same symptoms around the same time, doctors believe the synthetic marijuana was linked to the health episodes.
They do point out that because there was only four cases and they were unable to get a sample of the synthetic marijuana as well as the patients' serum and urine samples, they cannot claim that synthetic marijuana caused the acute kidney injury. Because there are many additives in the drug, it could be one of the particular chemicals not the cannabinoid that caused the damage.
"There is very little information regarding the ingredients in synthetic cannabinoids that are sold on the streets, although it is known that additional compounds are added to the preparations," Jain added. "It is very likely that a possible nephrotoxin adulterated the preparation used by our patients."
But, another study published in the CDC's Morbidity and Mortality Weekly Report on Feb. 14 showed that 16 cases of synthetic marijuana-related acute kidney injury were recorded in 2012, suggesting that there may be more links to the designer drug and kidney damage.
Dr. Robert Glatter, an emergency medicine physician at Lenox Hill Hopsital in New York who was not involved in the study, told CBSNews.com that he thought the study brought awareness to an important issue: Synthetic marijuana is dangerous.
"We know that products like K2 and Spice are dangerous and can cause agitation, acute psychosis, acute elevations in blood pressure leading to acute coronary syndromes -- however this study points out another significant risk of this dangerous synthetic compound," he said.
The authors recommended that medical professionals ask about designer drug use when looking at patients who may have potential kidney injuries, especially if the cause is unknown and a urine screen turns up negative for drugs. They also warn young people that synthetic marijuana -- even though it's not a "real" drug -- can have real consequences.
"If they don't get to a physician in time, the damage to their kidneys could be permanent, and they could end up on dialysis," Jain added.