New research by scientists at Washington State University suggests that using cannabis alongside other drugs may come with a significant risk of harmful drug-drug interactions.
The researchers found that cannabinoids, a group of substances found in the cannabis plant, can interfere with enzymes that help metabolize a wide range of drugs prescribed for various conditions.
This interference may result in decreased positive effects or increased negative effects of these drugs, leading to unintended side effects like toxicity or accidental overdose.
Enzymes Affected by Cannabinoids
Two enzyme families, cytochrome P450s (CYPs) and UDP-glucuronosyltransferases (UGTs), help metabolize and eliminate over 70% of the most commonly used drugs.
The researchers examined the interaction between three abundant cannabinoids—tetrahydrocannabinol (THC), cannabidiol (CBD), and cannabinol (CBN)—and their metabolites with all major CYP enzymes. They also studied the interactions between these cannabinoids and UGT enzymes.
The study found that cannabinoids and major THC metabolites strongly inhibited several CYP enzymes, and all three cannabinoids, especially CBD, inhibited primary UGT enzymes present in the liver and kidney.
Potential Consequences of Drug Interactions
The researchers warn that these interactions between CBD and UGT enzymes could inhibit kidney function in patients with acute kidney disease or kidney cancer, who may be using CBD to treat pain or reduce the side effects of anti-cancer drugs.
This interference may have long-term effects and serious ramifications for anti-cancer drugs, among other medications that could potentially be affected by cannabinoid-enzyme interactions.
Physicians need to be aware of the possibility of toxicity or lack of response when patients are using cannabinoids.
It’s essential to be cautious when using cannabis with other prescription drugs, especially for older people who are using medications, as taking CBD or medicinal marijuana may negatively impact their treatment.
The findings of this research were published in two studies in the journal Drug Metabolism and Disposition.
Further research is needed to better understand these interactions, but this early evidence suggests that being mindful of potential drug interactions is crucial when using cannabis alongside prescription medications.