Can you smoke weed on antibiotics?

Scientifically reviewed by Codi Peterson, PharmD

There is very little research on the combination of antibiotics and cannabis (Shutterstock)

Antibiotics are some of the most common medications, typically used to treat bacterial infections – so many wonder whether it is safe to continue using cannabis while taking a course of antibiotics. While research is extremely limited on the topic, there are no reports of problems mixing these two medications. Still some, but not all, antibiotics do list cannabis as a contraindication because of the potential to increase either the negative side effects of either the antibiotics or the cannabis. In addition, many compounds in cannabis have potent antibacterial effects on their own, and are being considered by researchers as a new antibiotic treatment against difficult to treat strains of bacteria.

Is it safe to mix cannabis and antibiotics?

One of the biggest questions about mixing cannabis and antibiotics is whether it is safe. Unfortunately, very little research has been done to see whether cannabis and antibiotics impact each other in ways that could be harmful. At the same time, despite an increase in overall cannabis use and potency in recent years, we have not seen case reports popping up about negative impacts from this common combination. However because many components of cannabis are processed via the liver metabolic pathways as some antibiotics, certain combinations of cannabinoids and antibiotics may increase side effects of either drug. Make sure to let your doctor know that you are using cannabis so they can prescribe an option that will not carry the risks of added side effects.

Will using cannabis reduce the effects of antibiotics?

While some worry that cannabis may reduce the effectiveness of antibiotics, we don’t have any research that suggests this is the case. In fact, compounds in cannabis, such as CBD, have antibacterial effects of their own and could be used to enhance the effectiveness of certain antibiotics against resistant strains of bacteria. As it turns out, many cannabinoids and terpenes have antibacterial effects. Fighting off bacterial threats is actually one of the functions that these cannabinoids and terpenes serve in protecting the plant’s overall health – so it’s an added bonus that might be able to help to protect us as well. ¹ ² ³

Which antibiotics are safe to use with cannabis?

There is always some risk when mixing medications that have not been intensively studied together. But at the same time, we don’t have much research suggesting antibiotics in general are unsafe with cannabis. While certain types of antibiotics won’t interact poorly with cannabis – some antibiotics do. Additionally the term cannabis isn’t descriptive enough, as CBD and THC interact with certain medications differently, so knowing the chemical profile of the cannabis product you’re using is important. Always double check with your doctor or pharmacist that an antibiotic is appropriate for use with a cannabis product.

Cannabis is generally okay to take with:

Amoxicillin
Amoxicillin/Clavulanate
Cephalexin
Cefdinir
Doxycycline

Cannabis may interact with:

Clindamycin
Erythromycin
Clarithromycin
Azithromycin
Sulfamethoxazole/Trimethoprim
Rifampin
Metronidazole

Note: these lists are not exhaustive.

Sometimes the concern with drug interactions is that cannabis can slow or hasten the clearance of the antibiotics, and CBD is generally of more concern than THC in this case. The other thing that can happen is that certain medications may reduce the metabolism of the cannabis itself, resulting in higher than expected blood levels of cannabinoids. This could lead to increased psychoactive side effects from cannabis, such as anxiety, dizziness, drowsiness, or paranoia.

CBD and THC can both alter the metabolism of certain drugs by inhibiting or inducing certain enzymes in the liver (CYP450 enzymes), which are responsible for breaking down many kinds of chemicals from the body. Additionally, CBD may inhibit an important proteins known as P-glycoproteins (P-gp’s) and a few others metabolic enzymes . Because of this, cannabis has the potential to effectively raise the levels of certain antibiotics. This would increase the likelihood of negative side effects from the antibiotics, which can range from minor things like nausea to major side effects like dangerous skin eruptions. Smoking Type I cannabis (high-THC) can also induce CYP1A2 enzymes, which could lead to more rapid metabolism of certain prescription medications, though this effect may be more related to smoking than to THC itself. ⁴ ⁵ ⁶

Can you take edibles and antibiotics?

While there is no specific research on combining edibles and antibiotics, because of the potential interaction with the p450 enzymes, this impact might be magnified by taking these together. If you are using cannabis edibles with antibiotics, it may be safer to take them separately and spaced out from each other. Always consult with your doctor before beginning use of the two together.

What can happen when you mix cannabis and antibiotics?

*Always talk to your doctor or pharmacist before mixing cannabis with an antibiotic (Shutterstock)*

When you mix cannabis and antibiotics there are a few things that might happen, depending on the type of antibiotics used. While there is some strong preclinical evidence to suggest that combining cannabis with antibiotics can actually increase the effectiveness against certain orgasmisms, human studies on the topic are virtually nonexistent. ⁷

The truth is there is very little way to know if it’s the cannabis causing any of these side effects. Based on the research and clinical concerns raised in the scientific literature, mixing the two may cause:

Increased side effects from THC ⁸
- Anxiety
- Abnormal behavior
- Confusion
- Depression
- Hallucinations
- Memory impairment
- Paranoia

Increased side effects of antibiotics ⁹
- Nausea
- Vomiting
- Diarrhea
- Rare but serious serious side effects like:
  - Liver toxicity
  - Low white blood cells
  - Serious skin disorders
  - Tendon and joint issues

Can cannabis actually be an alternative to antibiotics?

Interestingly, cannabis actually holds potential as an antibiotic all on its own. Many cannabinoids and terpenes have antibacterial effects, including terpenes like linalool, limonene, and α-pinene and cannabinoids such as THC, CBD, CBN, CBC,and CBG. The acid forms of many of these cannabinoids, like CBDA, CBGA, and THCA, may hold their own value as antimicrobials as well. ¹⁰

Some researchers are even considering cannabis as an alternative to our antibiotics – particularly for strains of bacteria that are resistant to conventional antibiotics like Staphylococcus aureus bacteria, also known as MRSA. In some cases, cannabis can actually be more effective than conventional antibiotics when bacteria has become resistant to these commonly used treatments. Researchers say we need alternatives like this so we can continue to fight against these resistant strains and cannabis could be an ideal next option – both alone or in combination with modern antibiotics. ¹¹

That being said, it’s absolutely not recommended to simply swap out cannabis for a course of antibiotics. We don’t have any research that suggests any particular cannabis treatment would be effective as an antibiotic alternative. Depending on the severity of the infection, making this choice could lead to a worsening infection, which could lead to serious illness or even death.

The bottom line on mixing cannabis and antibiotics

The bottom line on cannabis and antibiotics is that there is very little research on the combination. Still, while it is certainly possible that there are unknown adverse effects, there are many antibiotic options where cannabis is not contraindicated. For those antibiotics that are contraindicated, the combination may cause increased side effects from either the antibiotics or the cannabis. There is a lot of hope and potential for cannabinoids and terpenes to increase the efficacy of antibiotics, or even to be used as an alternative to certain antibiotics in the future. For now, anytime you are considering mixing cannabis with an antibiotic, it is best to discuss the decision with your doctor or pharmacist.

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