Is It Safe to Consume Cannabis While Taking Antibiotics?

With the widespread use of both weed and antibiotics, many wonder about the safety of mixing the two. After all, plenty of folks rely on cannabis for its pain-relieving properties. Smoking good quality flower, or having a cup of cannabis-infused tea, can be just the thing to help you deal with the symptoms of aches and chronic pain. 

Plus, many pain and inflammatory-based conditions or illnesses may have a treatment plan that includes antibiotics. However, what happens when you use THC and antibiotics together?

Antibiotics have been known to render certain medications less effective when consumed simultaneously due to their interactions. When treatment plans are complicated by consuming interacting drugs, including cannabinoids, drug levels can become altered. This theoretically poses a health risk. 

However, a 2014 systematic review study suggests that major cannabinoids like cannabidiol (CBD), cannabinol (CBN), and tetrahydrocannabinol (THC) interactions with pharmaceutical drugs are generally low risk according to the available data, but further research is still necessary to determine the specific effects of metabolites and other effects. On the flip side, it’s also reassuring that there aren’t any case studies documented to indicate a serious risk –  which likely would have happened by now if the theoretical risk was significant.

So, in light of this possibility between antibiotics and cannabis, let’s assess the impact on effectiveness and risks.

What Are Common Antibiotics?

Antibiotics are often used to treat and prevent the contraction or spread of bacterial infections, not viral infections such as the common cold. According to the NHS, antibiotics are used to (1) clear up a problem such as acne, (2) prevent the spread of conditions such as chlamydia, (3) speed up recovery in conditions such as a kidney infection or post-surgery, and (4) reduce risks of serious infections and subsequent complications such as pneumonia as well as post-surgery risks. The NHS and the CDC also advise selective antibiotic use in order to minimize the spread of drug-resistant organisms.

There are hundreds of antibiotics with the potential to react with medical cannabis. Penn State College of Medicine published a study that identified 139 common pharmaceutical medications that have the potential to cause adverse reactions when smoking marijuana. 

However, just because they only identified 139 out of hundreds does not mean that there is no risk of negative interactions among the rest. The following pharmaceuticals are the top ten most commonly used types of antibiotics, which will be looked at against the Penn State list:

• Amoxicillin
• Azithromycin
• Cephalexin
• Clindamycin
• Combination: Amoxicillin and Clavulanate 
• Combination: Sulfamethoxazole and Trimethoprim
• Doxycycline
• Erythromycin
• Metronidazole
• Levofloxacin

Dr. Kent Vrana, a professor and the chairman of pharmacology at the College of Medicine, along with Paul Kocis, published a shorter list of 57 medications based on the fact that they may not operate as intended alongside cannabis consumption. On the list these professionals compiled, the only antibiotic on the narrowed list is clindamycin. 

This also points out that the available pharmaceutical data this study draws from are still limited and incomplete, among other study limitations. Other safety data show such interactions likely pose a low but not insignificant risk. 

Dr. Vrana and the rest of the research team wanted to provide physicians with comprehensive information to make safe prescription choices for the sake of their patients. Dr. Vrana stated that “it’s important for medical professionals to consider the list when prescribing medical cannabinoids and how it may affect other medications a patient is taking.”

How Does Weed Affect Antibiotics?

Cannabis doesn’t seem to significantly interfere with the antibacterial effects of most antibiotics. However, some antibiotics, like rifampin, can decrease levels of THC and CBD when taken together, though both are generally well-tolerated when taken together. 

It’s important to be cautious when adding other medications that are metabolized similarly to cannabis, as metabolic interactions can occur. Drug interactions may lead to either a possible buildup or deficiency of the medication in question.

Can You Smoke Weed on Antibiotics? 

Smoking weed while on antibiotics may not completely neutralize the medication, but it’s still best to consult your doctor before mixing the two. Your doctor will want you to complete the full course of antibiotics to prevent antibiotic resistance and fully clear the infection. Always inform your healthcare provider about cannabis use when starting new prescriptions.

Potential Benefits and Risks of Mixing Cannabis and Antibiotics

While cannabis use is becoming more widespread, it’s important to understand how it may interact with prescription medications like antibiotics. Here are some potential benefits and risks you should be aware of.

Potential Benefits

Cannabis has shown antibacterial properties, potentially offering added benefits in fighting infections like MRSA. It may only be a matter of time before doctors are ready to add cannabis to the regimen of antibiotics they prescribe for patients who are having trouble kicking a nasty respiratory infection. 

THC is also shown to be a short-term, fast-acting bronchodilator. This means it may help open up the airways when they get tight, which could be useful in response to inflammation or infection. Cannabinoids cannot yet replace traditional asthma medications or antibiotics but may help alleviate certain symptoms in the short term.

Additionally, cannabinoids may help manage symptoms such as pain, inflammation, or anxiety, making the healing process more comfortable while taking antibiotics. Based on limited data, cannabis use doesn’t seem to interfere with most antibiotics, meaning the antibiotics should still work effectively.

Potential Risks

Although cannabis doesn’t usually neutralize antibiotics, it does use the same liver metabolic pathways as many prescription drugs, which could lead to drug interactions and alter how both cannabis and antibiotics work in your system. Smoking cannabis while on antibiotics could also irritate your respiratory system, potentially worsening any lung-related conditions. 

Moreover, the lack of extensive research means that the long-term effects of combining cannabis with antibiotics are still not fully understood, and side effects like dizziness, cognitive distortion, or fatigue may be amplified.

Another concern is that cannabinoids like THC bind to the CB2 receptor, responsible for regulating the immune response. If your immune response is dampened by THC, it could make fighting off the infection more difficult. So far, there is some evidence to support this immunosuppressant effect in certain infections, but not all are known yet.

Final Thoughts

If you’re considering smoking weed on antibiotics, it’s best to consult with your healthcare provider before doing so if you are otherwise healthy. This also presumes you are not worsening a lung infection with inhalational methods, and are aware of the side effects of antibiotics and potential adverse events of cannabis as well. Healthcare professionals are the experts on the antibiotics being prescribed, and they’ll be able to tell you with authority whether it will be appropriate for you. 

Remember that despite the legal status of cannabis where you live, bringing questions to your doctor is always encouraged, and your conversations are confidential — with or without a medical marijuana card. Your doctor will provide you with medical advice without legal judgment. Also, remember that if you are still uncertain after consulting your primary physician, you can get a second opinion.

Lastly, cannabis users should consume carefully and in moderation at first, while avoiding consumption methods that involve combustion and switching to CBD-only products for the duration of the antibiotic course to minimize adverse effects of high-THC cannabis.

Frequently Asked Questions

Does CBD affect antibiotics?

CBD may interact with some antibiotics by using the same liver enzymes to break down the medication. This can affect how the body processes both the antibiotic and the CBD, either by lowering (most likely) or increasing their levels, depending on the exact medication. Always check with your doctor before using CBD with antibiotics.

Can you mix THC and amoxicillin?

There is no strong evidence of an interaction between amoxicillin and THC. However, since both are processed by the liver, it’s best to consult with your doctor to avoid any potential issues. Monitoring how you feel while taking both is important.

Can you smoke while taking medication?

Smoking, including cannabis, while on medication can irritate your lungs and worsen certain conditions. It can also affect how the body processes the medication. It’s safer to use other forms of cannabis, like edibles or oils, while on medication.

This article was originally written in July 2023 by Chane Leigh and updated in November 2024.