Drug-drug or drug-supplement interactions are frequent, and the reason for concern. The reason is that more than half of adults in the US take prescription drugs regularly, and at least three-quarters of Americans have ever taken over-the-counter medications. Many people take more than one medicine.

It is obvious that these drugs may interfere and affect the metabolism of each other.

Also, interactions make drugs less effective, cause unwanted side effects, or increase the action of a particular medicine. Some medications, when interfering, become harmful for the patients. Interactions may lead to psychological problems that can be avoided.

Cannabis is one of the most widely consumed substances in the US and throughout the world. As cannabis users take it to treat various health problems, they also consume other medicines.

The increasing acceptance of cannabis and CBD-related products as a therapeutic option creates a need to study how their components interfere with other drugs.

Before we learn CBD interactions, first, it is necessary to understand how the human body absorbs CBD and medicines.

CBD metabolism

CBD enters into the digestive tract and slowly runs through the stomach into the hepatic system where the body filters this compound. Anything that ends up in the liver is metabolized and turned into different substances or metabolites¹.

Depending on the drug, metabolites can boost or reduce the drug’s effectiveness. Some studies found that some CBD metabolites may be rather beneficial².

Enzymes metabolizing CBD

Cytochrome P450 enzymes are responsible for metabolizing CBD. When CBD enters the liver, it takes over the enzyme’s capabilities. Therefore, the liver cannot break down other drugs properly³.

Currently, the duration of the effect of CBD in the liver has not yet been well researched. But, of course, it depends much on the mode of administration of CBD and the type of CBD oil taken (whether it is CBD dominant or THC dominant product).

Benefits of CBD interactions

Some interactions can be beneficial enough to help users with their health problems. Thus, some findings show that increased drugs in the bloodstream and their increased action mean that patients may reduce their dose of medications taken regularly².

Some recent studies are researching interactions of CBD with:

• cannabinoid-opiate interactions
• CBD, THC, and chemotherapy
• CBD, THC and blood thinners (one may need to adjust/reduce the dosage of medications)

Negative effects of CBD interaction

According to some researches, CBD might trigger toxic levels of certain drugs in the bloodstream¹. For example, certain anticoagulant drugs also use Cytochrome P450 enzymes for metabolism. When CBD consumed, it can cause increased anticoagulant blood levels⁴.

This shows that every patient deciding to use CBD in conjunction with other drugs must speak to a medical expert to avoid side effects and to obtain the best outcome.

References

1. Welty TE, Luebke A, Gidal BE. Cannabidiol: Promise and Pitfalls. Epilepsy Curr. 2014;14(5):250-252. doi:10.5698/1535-7597-14.5.250
2. Geffrey AL, Pollack SF, Bruno PL, Thiele EA. Drug-drug interaction between clobazam and cannabidiol in children with refractory epilepsy. Epilepsia. 2015;56(8):1246-1251. doi:10.1111/epi.13060
3. Guengerich FP. Cytochrome P450 research and The Journal of Biological Chemistry. J Biol Chem. 2019;294(5):1671-1680. doi:10.1074/jbc.TM118.004144
4. Coetzee C, Levendal R-A, Van de Venter M, Frost C. Anticoagulant effects of a Cannabis extract in an obese rat model. Phytomedicine Int J Phytother Phytopharm. 2007;14:333-337. doi:10.1016/j.phymed.2006.02.004