Recently, along with increased promotion of CBD products, there have been mounting concerns relating to this drug. The following is important information assembled from nationally recognized CBD studies and other reputable publications. We hope this article may shed light on some questions we have received.
CBD Oil and Drug Interactions:
Recent studies have found that CBD alters liver function, although the exact dose at which this occurs is unclear (White, p. 12). According to the Medical Marijuana Program, CBD is a “potent inhibitor” of vital enzymes which break down drugs and other toxins (p. 11). But why is this important?
A Quick Science Lesson: The two essential enzymes hampered by CBD are Cytochromes P3A4 and P2D6. CYP3A4 metabolizes about a quarter of all drugs, while CYP2D6 metabolizes many antidepressants (Medical Marijuana Program, p. 11). This means that CBD effects bodily drug concentrations including but not limited to: antihistamines, opioids, beta blockers, antipsychotics, tricyclic antidepressants, calcium channel blockers, and antiretrovirals (HIV medicines) – to name a few (Lynch and Price, p. 394).
Medicines which are metabolized by these enzymes:
Clarithromycin, Telithromycin, Erythromycin
Restasis, Sandimmune, Neoral, Gengraf
Celexa, Lexapro, Prozac, Paxil
Dayquil, Nyquil, Theraflu
Xanax, Valium, Ambien
Lipitor, Zocor, FloLipid
(Flockhart DA., 2007)
Observed from the list above, a wide range of medications are affected by CBD. Most of these medications can have serious side-effects in incorrect concentrations. Some of these drugs also have the potential to produce severe toxicity in the blood if not metabolized by the body correctly. Despite these risks, the absence of scientific consensus and standardized dosing has slowed regulation of CBD. This means, currently, there is no legal need to provide a drug interaction warning on CBD products.
However, CBD is not the only substance which hinders these enzymes. Grapefruit juice is also a known CYP3A4 inhibitor, while medications like Benadryl and Paxil both inhibit CYP2D6 (Bailey et al., p.101; Lynch and Price, p. 393). Look at the warning labels on your medications to see if they advise against grapefruit or Benadryl. This reading is intended to be general information, please check with your health care professional for further drug interaction information.
Written and produced by The Lexington Group EAP.
Bailey, D. G., Malcolm, J., Arnold, O. and David Spence, J. (1998), Grapefruit juice–drug interactions. British Journal of Clinical Pharmacology, 46: 101-110. doi:10.1046/j.1365-2125.1998.00764.x
Flockhart DA. Drug Interactions: Cytochrome P450 Drug Interaction Table. Indiana University School of Medicine (2007). “https://drug-interactions.medicine.iu.edu” Accessed 27 Sept. 2019.
Lynch, Tom, ParmD, and Amy Price, MD. “The Effect of Cytochrome P450 Metabolism on Drug Response, Interactions, and Adverse Effects.” American Family Physician 3rd ser. 76 (2007): 391-396. American Academy of Family Physicians. Eastern Virginia Medical School, 1 Aug. 2007. Web. 27 Sept. 2019. <https://www.aafp.org/afp/2007/0801/p391.pdf>.
United States Department of Justice. Drug Enforcement Administration. Diversion Control Division. Rosenberg, Chuck. Rules – 2016. Government Publishing Office, 14 Dec. 2016. <https://www.deadiversion.usdoj.gov/fed_regs/rules/2016/fr1214.htm>.
United States Health Regulation and Licensing Administration. Medical Marijuana Program. Medical Cannabis Adverse Effects & Drug Interactions. Adriane Fugh-Berman, Susan Wood, Mikhail Kogan, Donald Abrams, Mary Lynn Mathre, Andrew Robie, Janani Raveendran, Kofi Onumah, Rikin S. Mehta, Shauna White, and Jawara Kasimu-Graham. Department of Health, n.d. Web. 27 Sept. 2019. <https://doh.dc.gov/sites/default/files/dc/sites/doh/publication/attachments/Medical%20Cannabis%20Adverse%20Effects%20and%20Drug%20Interactions_0.pdf>.
United States Senate Committee on Agriculture, Nutrition, and Forestry. Agricultural Marketing Act of 1946. (Title II, Subtitle G, Sec. 297A). Government Publishing Office, 20 Dec. 2018. <https://www.agriculture.senate.gov/imo/media/doc/Agricultural%20Marketing%20Act%20Of%201946.pdf>.
White, Jason, Sharon Walsh, Susanna Babalonis, and J. Rehm. Critical Review Report. Rep. World Health Organization, 4 June 2018. Web. 27 Sept. 2019. <https://