A great deal of research has shown that CBD can interact with prescription medication. 1.,2.,3.,4.,5.,6. CBD can interact with different medications in different ways and these drug-drug interactions can cause unwanted and unexpected side-effects. It is therefore strongly advised to seek advice from your GP or specialist doctor prior to using CBD products. Cytochrome P450 (CYP450) isoenzymes are involved in the metabolism (break down) of different medications. CBD has been reported to inhibit several of these metabolic enzymes and as such can influence the action of prescription medication. 5. Adverse side-effects are also likely to increase if you are prescribed more than one medication. Patients taking at least two prescription medications had a 13% risk of an adverse drug-drug interaction, which increased to 38% for four medications and 82% with greater than seven medications. 6.
How CBD interacts with Prescription Medication
Evidence shows that CBD can increase the bioavailability (quantity of a substance available for use within the cells of the body) of some medications and decrease it in others. Increases can result in more severe medication side effects, while decreases can result in the reduced effectiveness of the medication. 7. Conversely, different medications can either increase or decrease the bioavailability of CBD. Again, increases in bioavailability can result in more severe CBD side-effects, while decreases can result in the reduced effectiveness of the CBD, so increased doses are required to gain the same therapeutic effect.
CBD and the Liver
Research has also found that CBD can also increase transaminase liver enzymes 1.,2.,3.,4.,5.,6. so shouldn’t be taken with prescription medication with the potential to cause liver damage (or by people who already have liver damage). The FSA noted that signs of adverse effects on the liver were seen at a CBD dose of 5 mg/kg body weight in patients and in healthy human volunteers (equivalent to 350 mg in a 70 kg adult).
What to do if you want to take CBD with prescription medication
The general advice is, that if you already take medication and want to take CBD products too, you should start off with a very low dose and increase it slowly over a few weeks, while keeping a close eye out for potential side effects. But you should do this under the advice and supervision of your doctor for your own safety. I’m not a medical practitioner so can’t and won’t give medical advice. Your doctor should also be able to tell you the recommended time period you should leave between taking your medication and CBD to lessen the chance of potential interaction issues that could occur if they were taken together.
NEXT: “3rd Party Laboratory Testing”
1. Larsen, C. and Shahinas, J., 2020. Dosage, efficacy and safety of cannabidiol administration in adults: a systematic review of human trials. Journal of clinical medicine research, 12(3), p.129.
2. White, C.M., 2019. A review of human studies assessing cannabidiol’s (CBD) therapeutic actions and potential. The Journal of Clinical Pharmacology, 59(7), pp.923-934.
3. Millar, S.A., Maguire, R.F., Yates, A.S. and O’Sullivan, S.E., 2020. Towards better delivery of cannabidiol (CBD). Pharmaceuticals, 13(9), p.219.
4. Sholler, D.J., Schoene, L. and Spindle, T.R., 2020. Therapeutic Efficacy of Cannabidiol (CBD): a Review of the Evidence From Clinical Trials and Human Laboratory Studies. Current Addiction Reports, pp.1-8.
5. Morales, P. and Reggio, P.H., 2019. CBD: a new hope?. ACS Med. Chem. Lett. 2019, 10, 5, 694–695
6. Chin, G.S., Page, R.L. and Bainbridge, J., 2020. The Pharmacodynamics, Pharmacokinetics, and Potential Drug Interactions of Cannabinoids. In Cannabis in Medicine (pp. 49-61). Springer, Cham.
7. Brown, J.D. and Winterstein, A.G., 2019. Potential adverse drug events and drug–drug interactions with medical and consumer cannabidiol (CBD) use. Journal of clinical medicine, 8(7), p.989.