In some chronic users, however, it can have an opposite effect and cause constant vomiting and abdominal pain, and the number of people affected appears to be growing in Augusta, says an emergency medicine physician at Georgia Regents University.
States that have decriminalized it also have a much higher rate of accidental ingestion by children, who then get sick, a recent study found.
A bill has been introduced in the Georgia Legislature that would allow medical marijuana in very limited circumstances, using a cannabidiol oil for people with seizure disorders, according to the Web site of one of its main sponsors, Rep. Allen Peake, R-Macon, who refused a request for an interview Thursday.
In other states, marijuana can be used for a wide variety of problems, and in Colorado and Washington state it is cleared for recreational use.
Those states that decriminalized the drug saw a 30 percent increase per year from 2005 to 2011 in calls to poison control centers concerning children age 9 or younger sickened by accidentally ingesting marijuana, usually by eating a marijuana-laced food product, according to a study published this week in the Annals of Emergency Medicine.
Many of these products, such as brownies or candies, are indistinguishable from normal products but can contain high levels of the psychoactive ingredient in marijuana, tetrahydrocannabinol, the study stated.
“We are concerned that kids are potentially getting into these things that have high amounts of THC and they can potentially develop some symptoms that we’re not traditionally thinking about when it comes to marijuana exposures in kids,” said George S. Wang, the lead author of the study and an assistant professor of pediatrics at the University of Colorado and Children’s Hospital Colorado.
Many of those products are not meant to be multiple servings but a small child won’t know any differently, he said.
“Some of these products are quite concentrated, quite potent,” Wang said.
After seeing evidence of accidental exposure with some hospitalizations, the Colorado Legislature moved to require recreational marijuana products be put into child-resistant packaging, a move that Wang said other states should take note of.
Even in adults, frequent chronic use of marijuana can result in a condition called cannabinoid hyperemesis syndrome, or cyclic vomiting and abdominal pain. It was first described in Australia in 2004, and since then more than 100 case reports in the U.S. have been reported; still, many physicians just don’t know about it, said Dr. Larry Mellick, a professor of emergency medicine at GRU and Georgia Regents Medical Center.
“It is not on everybody’s radar just yet,” he said.
He told of a patient last week who had been to the ER seven times before Mellick saw her, with several tests and scans that proved negative before she got the right diagnosis.
“And this is typical,” he said. “Every patient I’ve seen here has had multiple visits in ERs around the CSRA. They’ve had CT scans, they’ve had lab tests, they’ve had ultrasounds. Repeatedly, nothing shows up. It’s consistently negative. And the diagnosis just isn’t being made.”
Many of the patients find temporary relief by taking hot showers or baths, and for some that becomes a compulsion that can aid in getting their diagnosis. Anti-nausea drugs seem to work only short-term, but Mellick said that he has found giving them the drug Haldol helps relieve abdominal pain and vomiting and that others found success with the drug Ativan.
Abstaining from marijuana ultimately seems to relieve their symptoms, Mellick said.
Exactly why some patients would develop the problem is largely unknown, although there are lots of theories. THC affects receptors in the brain and stomach, and although one might cause an anti-nausea effect it might be reversed in the long-term by stimulation of the other.
One case report stated that although marijuana has been smoked for thousands of years, its potency might be much higher now. It pointed to research at the University of Mississippi’s Potency Monitoring Project of seized marijuana in which THC levels had increased from 3.4 percent in 1993 to 8.8 percent in 2008.
Mellick said that the anti-nausea and vomiting properties are well-known but that there are number of other metabolites in marijuana that can accumulate in the body and might exert a toxic effect, particularly in people who might be genetically susceptible to it. The problem would be if an already nauseated patient, such as one on chemotherapy, turns to the drug and gets the opposite effect in the long-term, Mellick said.
“Now the treatment they were hoping would make them feel better is actually complicating their illness even more,” he said.
What the syndrome points out is that there is a real lack of good research on marijuana, Mellick and Wang said.
“I think there is a lot we don’t know about marijuana, both the good and the bad,” Wang said. “I think as more states pass legislation and the use goes up, we’re going to be finding out more of the short- and long-term consequences, both good and bad, of medical and recreational marijuana. I think there are a lot more questions than answers at this point.”
With at least three cases of cyclic vomiting from heavy marijuana use in the past month, however, Mellick says he might be spotting a trend.
“I think there may be an upswing potentially happening,” he said.