Combining Cannabis With Prescription Drugs Could Lead To Harmful Interactions
The cannabinoids found in marijuana and their metabolites could negatively interfere with a range of prescription drugs. According to researchers at Washington State University, using marijuana in combination with prescription drugs can either decrease the drugs’ positive effects or increase their negative side effects. In some cases, mixing the two can also lead to toxicity and accidental overdose.
“Physicians should be aware of the possibility of toxicity or lack of response when patients use cannabinoids,” said Philip Lazarus, lead author of the papers and professor of pharmaceutical sciences at Washington State University. “It’s one thing if you’re young and healthy and smoke cannabis once in a while, but for older people who use medication, taking CBD or medicinal marijuana can have a negative impact on their processing.”
Lazarus and his colleagues have published a pair of studies looking at the interactions between cannabis and two families of enzymes that together are responsible for metabolizing and eliminating more than 70% of the most commonly used pharmaceutical drugs. . One study looked at cytochromes P450 (CYPs), while the other looked at UDP-glucuronosyltransferases (UGTs).
The comprehensive analysis not only examined the role played by the most abundant and important cannabinoids – tetrahydrocannabinol (THC), cannabidiol (CBD) and cannabinol (CBN) – but also their metabolites, the intermediate products of the reactions metabolic processes catalyzed by various enzymes that occur naturally in cells.
Cannabinoids like THC or CBD stay in your body for only 30 minutes before being broken down into smaller molecules, each with different effects. These metabolites persist in the body for much longer, up to 14 days in some cases. They also build up over time with continued use, so their concentration can be higher than that of the original cannabinoids. But despite their importance, the impact of these metabolites during interactions with other drugs has been neglected by previous studies.
The researchers first worked with individual human kidney cells that allowed them to zoom in on a single enzyme at a time, then validated their findings in human liver and kidney samples where many of these enzymes were present.
The results showed that cannabinoids and major metabolites of THC inhibited several CYP enzymes, particularly those found in the liver. All three cannabinoids, in particular CBD, inhibited two of the main UGT enzymes found in the liver. CBD blocked three enzymes that account for 95% of renal UGT metabolism, which plays a major role in removing toxins and certain drugs from your system.
“If you have kidney disease or take one or more drugs that are metabolized primarily by the kidneys and also smoke marijuana, you may inhibit normal kidney function, and this may have long-term effects. for you,” said Lazarus.
Many patients take prescription drugs for a variety of chronic conditions, from diabetes to cancer. These conditions are painful to live with, which is why some patients self-medicate with cannabis or cannabis-derived products like CBD. But using these anti-inflammatory products can end up doing more harm than good when combined with certain medications.
“Taking CBD or marijuana may relieve your pain, but could make the other drug you’re taking more toxic, and this increased toxicity may mean you can’t continue taking that drug,” the former said. author Shamema Nasrin, a graduate student. at the WSU College of Pharmacy and Pharmaceutical Sciences. “So there could be serious ramifications for cancer drugs, and this is just one example of the many drugs that could potentially be affected by the cannabinoid-enzyme interactions we’re seeing.”
Both studies appeared in the journal Drug metabolism.