Can I use cannabis while taking antibiotics? What does science say

Have you ever wondered if you can use cannabis while taking antibiotics? Although there is no robust evidence of serious interactions, the combination still requires attention, especially because there is a lack of broad studies evaluating how cannabinoids influence the metabolism of commonly used medications, as confirmed by the El Planteo website.

In the end, the answer is usually not a “yes” or “no”, but a “depends”, with room for care and medical guidance.

How the body processes cannabis and antibiotics

El Planteo also explains that both cannabis and various medications go through what is called first-pass metabolism, a liver stage whose function is to filter substances, break down molecules, and reduce potential excess before they circulate through the body. This means that often, cannabis and antibiotics “compete” for the same metabolic pathways.

Dr. Carolina Rosa, a family physician, confirms this dynamic. According to her, understanding the relationship between cannabis and medications, especially antibiotics, begins with understanding how the body processes each of them. “When we ingest any medication, it goes through the liver, where first-pass metabolism occurs. It is there that the body filters toxic substances, transforms molecules into smaller compounds, and reduces part of the initial potency of the medication to protect the body and facilitate its elimination,” she explains.

After this stage, the metabolized medication travels through the bloodstream to the organs, where it exerts its therapeutic effect. “Cannabinoids, such as CBD and THC, are also metabolized in the liver, by the same enzymes responsible for breaking down many medications, including some antibiotics. These enzymes are part of the cytochrome P450 system, a kind of chemical ‘power plant’ of the body,” she details.

When the interaction deserves attention

The physician emphasizes that in practice, this may mean that CBD slows down the elimination of some drugs, increasing their concentration in the blood, while THC tends to have milder interactions, but also uses the same metabolic pathways.

“Some antibiotics, such as clarithromycin and erythromycin, can increase CBD and THC levels, intensifying effects like drowsiness, dizziness, or fatigue,” says the physician. 

On the other hand, antibiotics like rifampicin do the opposite: they accelerate cannabis metabolism, reducing its therapeutic effects.

The good news, according to her, is that “more common antibiotics, such as amoxicillin, azithromycin, metronidazole, and cephalexin, usually do not cause significant interactions.” Still, the lack of specific research indicates that caution remains the safest path.

El Planteo reinforces this view by reminding that it is still not certain whether cannabis inhibits or induces certain liver enzymes, making it prudent to consult a professional before combining treatments.

For Dr. Carolina Rosa, the principle is simple: “The most important thing is always to inform your doctor about the use of medicinal cannabis before starting any new medication. This way, it is possible to monitor possible interactions, adjust doses when necessary, and ensure that both treatments are safe and effective.”

In the end, although cannabis is not automatically prohibited during antibiotic use, each body reacts uniquely, and individualized guidance continues to be the best way to safely navigate treatments.

With information from El Planteo.