According to new research by scientists out of Washington State University, using cannabis along with other drugs could create a significant risk for harmful drug interactions.
As part of the study, researchers looked at cannabinoids, a group of substances found in the cannabis plant, and their major metabolites found in cannabis users’ blood.
They had found that they interfere with two families of enzymes that help metabolize a wide range of drugs prescribed for a variety of conditions. This means either the drugs’ positive effects might decrease or their negative effects might increase with too much building up in the body, causing unintended side effects such as toxicity or accidental overdose.
The authors said one early takeaway from these studies is that it’s important to be careful when using cannabis with other prescription drugs. More research however needs to be done.
“Physicians need to be aware of the possibility of toxicity or lack of response when patients are using cannabinoids,” said Philip Lazarus, senior author on the papers and Boeing distinguished professor of pharmaceutical sciences.
“It’s one thing if you’re young and healthy and smoke cannabis once in a while, but for older people who are using medications, taking CBD or medicinal marijuana may negatively impact their treatment.”
The findings were described in a pair of studies published in the journal Drug Metabolism and Disposition.
“Cannabinoids stay in your body only for about 30 minutes before they are rapidly broken down,” said first author Shamema Nasrin, a graduate student in the WSU College of Pharmacy and Pharmaceutical Sciences. “The metabolites that result from that process stay in your body for much longer—up to 14 days—and at higher concentrations than cannabinoids and have been overlooked in previous studies, which is why we thought we should focus on those as well.”
“If you have a kidney disease or you are taking one or more drugs that are metabolized primarily through the kidney and you’re also smoking marijuana, you could be inhibiting normal kidney function, and it may have long-term effects for you,” Lazarus said.
“Taking CBD or marijuana might help your pain but could be making the other drug you’re taking more toxic, and that increase in toxicity may mean that you can’t continue taking that drug,” Nasrin added. “So, there could be serious ramifications for anti-cancer drugs, and that’s only one example of the many drugs that could potentially be affected by the cannabinoid-enzyme interactions we’re seeing.”