Cannabis use could cause harmful drug interactions

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In a new study at Washington State University, researchers found using cannabis alongside other drugs may come with a big risk of harmful drug-drug interactions.

They looked at cannabinoids—a group of substances found in the cannabis plant—and their major metabolites found in cannabis users’ blood.

They found that they interfere with two families of enzymes that help metabolize a wide range of drugs prescribed for a variety of conditions.

As a result, 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.

While more research needs to be done, the authors said one early takeaway from these studies is that it’s important to be careful when using cannabis with other prescription drugs.

In the study, the team focused on a family of enzymes known as cytochrome P450s (CYPs) and UDP-glucuronosyltransferases (UGTs), another enzyme family.

Together, these two enzyme families help metabolize and eliminate more than 70% of the most commonly used drugs from the body.

The team looked at the interaction between three of the most abundant cannabinoids—tetrahydrocannabinol (THC), cannabidiol (CBD) and cannabinol (CBN)—and their metabolites and all of the major CYP enzymes.

The researchers used human kidney cells to examine the interactions.

They found that cannabinoids and the major THC metabolites strongly inhibited several CYP enzymes.

One key discovery was that one of the most abundant THC metabolites appears to play a major role in inhibiting several key enzymes in the liver.

Looking at the UGT enzyme family, the researchers found that all three cannabinoids, but especially CBD, inhibited two of the primary UGT enzymes present in the liver.

CBD was also found to block three enzymes that account for about 95% of kidney UGT metabolism, which helps clear toxins and certain drugs from the body.

The team says if you have 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.

These interactions could be inhibiting kidney function in patients with acute kidney disease or kidney cancer, who may be using CBD to treat pain or to try to reduce the side effects from anti-cancer drugs.

If you care about cannabis, please read studies about high-potency cannabis that may affect your memory functions, and findings that people with this heart problem need to use cannabis cautiously.

For more information about cannabis, please see recent studies about cannabis could reduce blood pressure in older people, and results showing that medical cannabis could help reduce this brain disease.

The study is published in the journal Drug Metabolism and Disposition. One author of the study is Philip Lazarus.

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