Drug Interactions and CBD

Drug Interactions

Drug Interactions are a difficult and tumultuous subject to consider when talking about CBD. In this unregulated industry, little has been done to perform in-depth FDA approved studies to determine side effects and drug interactions. There are some basic principles that will help to lead to reasonable conclusions, but there still some assumptions to be made. We learn a lot from the one FDA approved pharmaceutical CBD isolate product (Epidiolex) which has been the subject of some of this research and supplies us with answers.

When talking drug interactions, we are talking about a drug’s effect on liver enzymes for the sake of this article. How does a drug effect various liver enzymes, and what is the effect? When multiple drugs are being used by a patient, and those drugs affect the same enzymes, what is the effect? That is what we are talking about.

Understanding drug interactions is more complicated than one might think. I have seen many articles and blogs written that get this critical point wrong. There are multiple levers that we need to pull when talking about drug-to-drug interactions. Sometimes the levers get pulled in opposite directions which only adds to the confusion! I will go into more detail below and I am always available for more questions on my website (www.awakentocbd.com) or at seangalerph@gmail.com.

Let us start with the easy part (wink, wink). What are drug interactions and what role does the liver play? Drug metabolism is a term used to describe the process by which the body undertakes to absorb, use, and then eventually break down and excrete a medication. Certain proteins called enzymes are responsible for drug metabolism, and are present in many tissues in the body, but they are primarily found in the liver. These liver enzymes impact how our body is affected by and reacts to the medications we ingest, and may slow or speed up certain chemical reactions which result in deactivating or excreting the medications we ingest.

There are 4 factors to consider when talking about drug interactions:

  1. The effect of a prescription or over the counter (rx/otc) drug on the enzyme itself. Does the drug inhibit the enzyme or activate it?
    1. A drug that inhibits an enzyme means there is less of that enzyme available to deactivate other medications (resulting in a longer time of that drug circulating than intended, or resulting in a more potent impact, which can lead to side effects). A drug that activates an enzyme means there is more enzyme available to deactivate other medications (resulting in less time of that drug being active, or the drug being less effective than intended, which can result in side effects).
  2. Does the rx/otc drug affect the same enzyme that metabolizes CBD? If so, that means that the drug and the CBD are competing for the attention of the enzyme and one or both may be impacted.
    1. I’ve provided a chart which reviews the most common medications that follow the same metabolic pathway as CBD.
    1. This chart will also clarify if the rx/otc medication inhibits or activates the enzyme.
  3. What is the strength of the bond that CBD or rx/otc medication make with the liver enzyme?
    1. The expected result from the drug interaction would depend on which compound (CBD or rx/otc medication) has the stronger bond to the liver enzyme – in other words, which one gets preference or priority in terms of what the liver enzyme affects first.
    1. For the sake of this blog, we will assume that CBD will take priority with the metabolizing enzyme which results in more of the rx/otc drug being made available in your body. This will result in an increased chance of side effects (and also an increase in potency of the medication as well).
    1. We are not as concerned about potential increases in CBD levels because it is a non-toxic medication and is still tolerable at very high levels. (See dosing levels for Epidiolex which are 20-30 times higher than CBD)
  4. Is the drug metabolized into a less active, or more active form? When a drug is altered by your liver enzymes into a more active form it is considered a prodrug.
    1. THC is a prime example of something being metabolized into a more active form. THC, or delta-9 THC, is the actual form of THC that we ingest from the hemp or marijuana plant. This form of THC is metabolized into 11-hydroxy-delta-9 THC which is primarily responsible for the high we associate with this medication.
      1. When administered together, CBD decreases the high because it prevents THC from being activated to its more potent metabolite.
    1. I have attached a chart with common prodrugs that could potentially be affected by CBD.
      1. A prodrug that is not metabolized would not work as well.

Now that I have thoroughly confused you, let us move on! Sometimes there is no straightforward way to explain chemistry and pharmacology, it just does not lend itself to rational explanation. Imagine how I felt in pharmacy school!

To summarize, most drug interactions with CBD will see a potential for worsening of side effects and an increase in the strength of the medication. Therefore, I urge you to consult a healthcare professional to gauge whether the interaction is significant enough to adversely affect your health or whether it is business as usual. I am not just tooting my own horn, but this is where doctors and pharmacists need to step up and help people to make educated decisions, especially in an unregulated market like CBD.

Some early assumptions that I tend to agree with state that CBD is not a strong binder to its liver enzymes and should only cause a mild increase in your medication or its side effects. That is not to say everyone responds the same! Some people will feel a dramatic difference from a minor increase in their medication depending upon the effectiveness of the rx, side effect profile, and genetic disposition of the individual.

The blood thinner Coumadin, or warfarin, has some of the most varied drug interactions for all prescription drugs. So, it is no surprise that we need to be careful when patients who are using warfarin are also considering dosing with CBD. I do not recommend starting CBD without first consulting your doctor in this situation. I also give similar warnings to anti-seizure medications as there a couple of serious interactions that must be accounted for. These drugs will be supplied in my list below of potential drug interactions.

For more resources such as my book, online course, and other blog articles, click on over to my website (www.awakentocbd.com). My goal is to provide with an abundance of clear, concise information as you navigate the often-nebulous world of CBD. You can also find CBD product for sale that has undergone a rigorous 14 step review process in order to pass muster with our CBD Pharmacist (that’s me!). You can be confident that you are making the best decisions for your health by choosing Awaken to CBD as your guide. And don’t forget that everything has a 30-day money back guarantee if you are not satisfied with your product. I wish you luck and better health along your CBD journey!

Sean Gale, The CBD Pharmacist

The views in this document are expressly the opinion of Sean Gale RPh, and are not meant to treat, diagnose, prevent or cure any disease states or medical conditions. Please consult your physician before beginning any CBD therapy. These statements have not been evaluated or approved by the FDA. Buyer is to consume CBD at their own risk. I may be reached for further questions at seangalerph@gmail.com.

Scroll to Top