What Kind of Drug Interactions Can Happen with CBD?

Posted on July 28 2021

What Kind of Drug Interactions Can Happen with CBD?


Many consumers are increasingly turning to CBD products as a natural alternative to everything from chronic pain relief to the treatment of ADHD, anxiety, and more. While CBD, one of the many compounds inherent to the cannabis sativa plant, may offer a nice alternative to current treatments, including prescription drugs, it’s important to be smart about how CBD could potentially interact with any other medications you’re taking. 

7 Common CBD Oil Drug Interactions

  • Antidepressants, such as Fluoxetine or Prozac 
  • Any drug that causes drowsiness, including antipsychotics and benzodiazepines 
  • Warfarin
  • Macrolide antibiotics like Erythromycin and Clarithromycin
  • Amiodarone
  • Levothyroxine
  • Seizure Medications Like Clobazam, Lamotrigine and Vaproate

CBD has many exciting possibilities when it comes to therapeutic treatment, but it’s important to remember that the research around is in the very early stages. Because researchers haven’t fully explored CBD’s mechanism of action (yet), it can be sometimes be hard to predict whether it will have interactions with other medications, both over-the-counter and prescriptions. What behaves as a safe and natural remedy for one patient could have unintended negative interactions with another patient, depending on the other compounds in the patient’s system. 

While we’ll outline some of the most common CBD oil drug interactions, it’s always important to visit with your doctor or consult with a pharmacist if you have any concerns about potential negative side effects.  

Does CBD Interact with Medications?

There’s reason to believe that, as safe as CBD has been shown when used alone, it may have the potential to negatively react with other medications to create some unintended side effects. 

CBD may at times react with over-the-counter medications, herbal products, and some prescription medications, which underscores the necessity of talking with a doctor or pharmacist before trying CBD products if you’re regularly taking a drug for a heart condition, pain or another medical condition. Some medications should never be taken with CBD, while others can be modified or reduced in order to decrease the chance of a negative CBD drug interaction. And while CBD information for medical professionals is in early phases, your doctor is still the best equipped to provide sound advice about how to safely use CBD for your particular medical condition.

According to Nina M. Bemben, PharmD, BCPS—a specialist in drug interactions—CBD, along with many other medications and compounds, are broken down for the body’s use by the liver enzyme family known as Cytochrome p450. Because CBD acts as an inhibitor to certain CYP enzymes, it could cause other medications in the body to be broken down more slowly—which, unless your doctor lowers your dosage, could lead to increased side effects. On the other hand, CBD can induce other CYP enzymes, which may lead to a faster drug metabolism, resulting in reduced efficacy unless the dosage is increased.

While much research is needed on exactly how CBD behaves within our bodies and how it interacts with various other medications, here’s a good general rule to remember: if you take a drug with a label that features a grapefruit juice warning, it’s a good idea to steer clear of any CBD product while you take that drug. Why? According to the U.S. Food and Drug Administration, a medication with this warning, taken together with grapefruit or grapefruit juice, can manifest at a higher than intended concentration within the blood, potentially causing adverse events. 

What does this have to do with CBD? A class of chemicals present in grapefruit juice, known as furanocoumarins, inhibit the enzyme CYP3A4—in much the same way CBD does, resulting in a slower metabolization of medications. So, if you’re taking a medication that features a grapefruit warning, there’s a good chance CBD may cause a few issues with that drug as well. More than 85 different drugs react negatively with grapefruit, including many of the following—you’ll notice a distinct overlap between this list and the list of drugs that commonly have a CBD drug interaction: 

  • Antibiotics and antimicrobials
  • Anticancer medications
  • Antihistamines
  • Antiepileptic drugs 
  • Blood pressure medications
  • Blood thinners
  • Cholesterol medications
  • Corticosteroids
  • Erectile dysfunction medications
  • GI medications, such as those used to treat nausea and GERD
  • Heart rhythm medications
  • Immunosuppressants
  • Mental health medications, such as to treat anxiety, depression, or mood disorders
  • Pain management medications
  • Prostate medications

The good news? Based on what we know about how CBD is metabolized, there doesn’t seem to be much concern over potential reactions to nonsteroidal anti-inflammatory drugs and/or other prescription medications used to treat the symptoms of arthritis. More good news: there are no reports of any life-threatening interactions that over-the-counter CBD products have had with any herbal, OTC, or prescription drug. Commonly reported side effects have included drowsiness, nausea, diarrhea, dry mouth, a decrease in medication efficacy and changes in appetite or weight.

With the help of your doctor, it’s possible to add CBD to your therapeutic regimen, even if you’re taking another prescription medication that could interact negatively with CBD. It may just be a question of adjusting dosage, monitoring liver function and/or carefully watching for side effects. 

We also want to stress that you should never forego your current medication to try CBD without talking with your doctor first. Some medications will need the dosage slowly tapered down in order to safely discontinue use, while others may require careful monitoring. 

7 Common CBD Oil Drug Interactions

Let’s take a closer look at common medications CBD oil may negatively interact with: 

1. Antidepressants, such as Fluoxetine or Prozac 

Some common medications prescribed for depression, such as Fluoxetine and Prozac, when combined with CBD, may increase drowsiness or dizziness. This can be dangerous for patients who are older or who otherwise experience mobility issues, as it may increase the chances for a dangerous or even life-threatening fall.

2. Any drug that causes drowsiness, including antipsychotics and benzodiazepines

Any drug that causes drowsiness, which is a surprisingly large collection, has the potential to combine with CBD for an intensified effect. Anyone who is taking these types of medications combined with CBD is at an increased risk for impaired judgment, falls, and other dangerous situations that result from excessive drowsiness.

3. Warfarin and Clopidogrel

Warfarin is a fairly common drug prescribed as a blood thinner. The most reliable information we have about CBD’s potential interaction with Warfarin comes from studies of the only FDA-approved CBD product, Epidiolex, which is a prescription treatment for rare forms of epilepsy. Epidiolex has been shown to increase blood levels of Warfarin by approximately 30 percent. With this increase comes a higher risk of excessive bleeding.  Clopidogrel also interacts with CBD.

4. Macrolide antibiotics like Erythromycin and Clarithromycin

These types of antibiotics are widely prescribed for the treatment of bacterial infections. Because CBD has the ability to slow down or speed up the metabolism of antibiotics by our CPY450 enzymes, taking antibiotics in conjunction with CBD may mean you end up with a higher dose of drugs in your system than is either safe or effective.

5. Amiodarone

Amiodarone is often prescribed to address irregular heart rhythm. CBD metabolism often is slowed down when taken in combination with Amiodarone, resulting in elevated levels of both medications in your system if they’re used together. In addition, both CBD and amiodarone can cause an elevation in liver enzymes, and the effect is exacerbated when the two are taken together.

6. Levothyroxine

Levothyroxine is a commonly prescribed thyroid medication. In fact, it is likely the most popular drug prescribed for thyroid issues. When CBD and levothyroxine are taken together, they are forced to compete within the CPY450 enzyme pathways for effective drug metabolism. This kind of drug interaction could cause thyroxine to accumulate, which could result in hyperthyroidism. In addition, when thyroid medications and CBD products are taken too closely together, some patients may experience short-term anxiety and mild nausea.

Seizure medications, like Clobazam, Lamotrigine and Vaproate
Clobazam, Lamotrigine, and Vaproate often are prescribed for patients experiencing seizures, either due to epilepsy or other health conditions. In some cases, CBD has increased the Clobazam levels of children treated with both Clobazam and CBD for epilepsy.


Does CBD Consumption Method Matter?

The manner in which you consume CBD absolutely has an effect on its potential to negatively react with other medications you take. Inhaling CBD, for example, deposits the compound almost immediately into your bloodstream, which allows it to reach peak concentration within 30 minutes. This delivery method avoids the liver’s metabolism, but may still increase the chances that CBD will negatively react with other medications already in your system. 

Edible CBD vehicles, like soft chews, CBD gummies, etc., take longer to absorb and reach peak concentration, but they also have the potential to reach a highly concentrated enough level that negative interactions are possible. The same is true for a CBD oil or emulsion tincture



CBD topicals, such as balms, creams, CBD lotion, etc., are the least likely to react negatively with other medications in your bloodstream because absorption through the skin decreases the amount of CBD that may eventually make its way into your bloodstream.

Other factors that influence both the occurrence and severity of a CBD interaction with other pharmaceutical drugs may include the age of the patient, the dosage amount of both CBD, and the interacting drug, plus any existing underlying medical conditions. Older patients may be at higher risk of potential negative drug interaction for a couple of reasons: first, as we age, the time our bodies take to process compounds like CBD and other medications increases, and second, older patients are more likely to take multiple medications on a regular basis. 

Your doctor can help you figure out what type of CBD and dosage may be right for you, considering your medical profile and any medications you already take on a regular basis.


Create a CBD Treatment Plan with Your Medical Team Today! 

CBD shows great promise in being able to offer patients relief from a wide variety of medical conditions, but it’s still in the early stages of research. If you want to try CBD, but are already taking a medication to treat your condition, make sure to confer with your doctor before adding CBD to your treatment plan or before using CBD to replace any of your current medications. 

Your doctor can help you develop a plan that will let you enjoy the highest therapeutic effect of CBD with the fewest possible side effects. And when you’re ready to purchase high quality, responsible CBD products, our team at Farmer & Chemist is here to help—we have a broad variety of CBD oils, creams, gummies, and more. Our team of pharmacists and pharmacy technicians are also available to answer any questions you may have about the appropriate use of CBD, as well as any potential drug interaction you need to speak to your doctor about. 

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