CBD Oil & Drug Interactions: A Complete Guide
Since its explosion into the mainstream consciousness in 2013, Cannabidiol (CBD) has quickly become a star cannabis compound thanks to its wide-ranging therapeutic benefits
By interacting with neurotransmitter receptors in the central nervous system, cannabinoids like CBD and THC can induce sedative effects on the user. While the sedative effects of THC are associated with drowsiness and lethargy, CBD induces sedative effects that are calming and wake-inducing. When combined with sedatives, cannabinoids produce an additive effect, meaning they can increase the effects of the medication. While the interaction between CBD and sedatives does not seem to have a directly negative effect on the user, the impact CBD can have on sedatives is not fully known. To play it safe, users should avoid combining CBD with sedatives.
CBD-rich products like capsules and tinctures are quickly growing in popularity thanks to their effectiveness and minimal known downsides.
An often overlooked topic is the way that CBD oil is metabolized by the body can have a significant impact on the processing of other drugs.
What is the Cytochrome P-450 System?
The cytochrome P-450 system is found within the liver and is responsible for metabolizing over 60% of pharmaceutical drugs available on the market today. Within this system, there are more than 50 enzymes that process and eliminate toxins.
The rate at which drugs are processed by this system plays a key role in helping doctors determine the appropriate dosing for a given medication. Changes to the way drugs are metabolized may occur if this system is not operating normally due to health issues or the consumption of other drugs.
Many compounds found in hemp oil are also processed by the P-450 system. For example, THC induces CYP1A2, reducing the levels of drugs metabolized by this enzyme. CBD inhibits CYP3A4 and CYP2D6, increasing the levels of drugs metabolized by these isoenzymes. (R)
This means that when consuming CBD products, many other drugs to take longer than normal to be processed by the body. This can result in negative side effects and complications. On the flip side, these interactions can be positive. These interactions can be used to lower dosage requirements, mitigate side effects, and improve the quality of life in some patients.
The important fact here is that CBD oil does interact with other medications and should be approached cautiously.
The Grapefruit Test: An Easy CBD-Drug Interaction Reference
You may have hears that physicians often warn their patients not to eat grapefruit before taking many medications. This is because several of the compounds in grapefruit also inhibit the cytochrome P450 system just like CBD does. CBD, however, turns out to be a more potent inhibitor than compounds in grapefruit like bergapten (the strongest of several grapefruit components that inhibit this system).
To make things easy, the grapefruit test is a great reference point for cannabidiol interactions. If your doctor has warned you about consuming grapefruit with any of your medications, it is a strong sign that you may see similar recommendations for CBD oil.
Known CBD Oil & Pharmaceutical Drug Interactions
As we mentioned above, the number of drugs processed by Cytochrome P450 is large. Luckily the Indiana University School of Medicine has produced a handy chart which outlines the drugs known to interact with this system. Here are some of the notable items from the list:
- NSAIDs (ibuprofen)
Angiotensin II Blockers
Proton-Pump Inhibitors (PPIs)
Estrogen Modulators (Tamoxifen)
Antidepressants (SSRIs, SNRIs, MAOIs)
Blood Thinners (Warfarin)
Calcium Channel Blockers
HMG CoA Reductase Inhibitors
Alcohol, Cannabis, & CBD Oil
As the popularity of cannabidiol continues to rise and the prohibition on marijuana use lifts, the chance that cannabis and alcohol will be consumed together continues to rise. The nightlife industry has adopted CBD as an ingredient, the beer industry is producing cannabis beer, and more people around the world are gaining access to marijuana for legal recreational use.
What is not widely understood is the effects of combining these two popular substances. Similar to the drugs we discussed above, alcohol depends on specific metabolic pathways in the body to be processed.
Specifically, the substance relies on the enzymes alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) to be processed under normal conditions. For those who binge drink or have chronic alcohol consumption patterns, the cytochrome P-450 system gets involved, specifically the CYP2E1 enzyme.
Cannabis compounds like CBD and THC are processed through the same pathways as alcohol. Anecdotal evidence and research clearly show a strong interaction between consuming alcohol and cannabis together. There are implications that make the decision to consume cannabis products and alcohol together something to carefully consider:
Consuming alcohol and marijuana together increases THC levels in the blood, but THC does not increase blood alcohol levels.
When CBD is combined with alcohol far lower blood alcohol levels were observed, but the effects of alcohol were not influenced.
Caffeine & CBD Oil
Perhaps one of the most common combinations for CBD users is the consumption of caffeine (via coffee or tea) alongside CBD. While scientific research on the subject is limited, it is well known that both CBD and caffeine act on the adenosine receptors.
It is important to note too that caffeine is metabolized by the CYP450 enzyme, specifically CYP1A2. This means that consuming CBD and caffeine together lead to a slower rate of caffeine processing through the body, resulting in a more drawn-out caffeine effect.
The interaction between these two substances is being anecdotally documented as the rise of CBD-infused coffee permeates popular culture.
CBD and other compounds in hemp oil may interact with a wide range of drugs. This article is not medical advice. If you are taking or plan on taking any medications and wish to begin using a CBD product of any kind, be sure to talk with your doctor first.