CBD Risks: Warnings for CBD Consumers

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Although research has shown that there are several benefits associated with the use of CBD. CBD users must also be aware that there are risks associated with taking CBD. These risks apply to all forms of CBD, whether it is in a CBD oil tincture or smokable hemp flower. CBD risks include drug interactions as well as CBD side effects and adverse events.

Several studies suggest that CBD is non-toxic in non-transformed cells and does not induce changes on food intake, does not induce catalepsy, does not affect physiological parameters (heart rate, blood pressure and body temperature), does not affect gastrointestinal transit and does not alter psychomotor or psychological functions. Also, chronic use and high doses up to 1,500 mg/day of CBD are reportedly well tolerated in humans. Conversely, some studies reported that this cannabinoid can induce some side effects, including inhibition of hepatic drug metabolism, alterations of in vitro cell viability, decreased fertilization capacity, and decreased activities of p-glycoprotein and other drug transporters.

Machado Bergamaschi, M., Helena Costa Queiroz, R., Waldo Zuardi, A., & Crippa, A. S. (2011). Safety and side effects of cannabidiol, a Cannabis sativa constituent. Current drug safety, 6(4), 237-249.

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CBD Risks: Drug Interactions

Drug interactions are a very big concern with CBD products. If you have ever seen a drug with a “grapefruit warning” those also apply to CBD products. CBD risks interfering with the way the liver metabolized drugs. Cytochrome P450 is the liver enzyme that is specifically altered by CBD.

Depending on the medications taken with CBD, the drug interaction CBD risks can make the drug more or less effective and make it active for more or less time, fundamentally altering how the body processes other substances like medications when also taking CBD.

Common [adverse drug events] include transaminase elevations, sedation, sleep disturbances, infection, and anemia. Given CBD effects on common biological targets implicated in drug metabolism (e.g., CYP3A4/2C19) and excretion (e.g., P-glycoprotein), the potential for [drug-drug interactions] with commonly used medication is high.

Brown, J. D., & 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), 989.

Which Drugs Does CBD Interact With?

Brown, J. D., and Winterstein, A. G. (2019) suggest that the following drugs can have interactions with CBD. Please note that this list is not all-inclusive. Some interactions may be “positive” while others are “negative.” In any case, if you are on any of these medications there is a high risk of interaction with CBD that you should speak with a doctor about!

CBD Risks: CYP3A4 Substrates

Immunosuppressants, chemotherapeutics, antidepressants, antipsychotics, opioids, benzodiazepines, z-hypnotics, statins, calcium channel blockers, others

CBD Risks: CYP3A4 Inhibitors

Protease inhibitors, ketoconazole, loperamide, nefazodone, amiodarone, verapamil, cimetidine, aprepitant, imatinib

CBD Risks: CYP3A4 Inducers

Enzalutamide, phenytoin, carbamazepine, topiramate, phenobarbital, rifampicin, efavirenz, pioglitazone

CBD Risks: CYP2C19 Substrates

Antidepressants, antiepileptics, proton pump inhibitors, clopidogrel, propranolol, carisoprodol, cyclophosphamide, warfarin

CBD Risks: CYP2C19 Inhibitors

Fluvoxamine, fluoxetine, proton pump inhibitors, cimetidine, ketoconazole, clopidogrel, fluconazole, efavirenz

CBD Risks: CYP2C19 Inducers

Rifampin, carbamazepine, phenobarbital, phenytoin, St. John’sWort

CBD Risks: CYP2C8/9 Substrates

Rosiglitazone, burprenorphine, montelukast, celecoxib, sulfonylureas, losartan, naproxen, phenobarbital, phenytoin, rosuvastatin, valsartan, warfarin

CBD Side Effects

Like any substance (natural or unnatural) CBD risks creating side effects and adverse effects. Since there is no standardization, dosage recommendation, long term safety data, or regulatory guidance in place for CBD products, consumers take a big risk when trying these products. It is always good to talk to a doctor before trying CBD!

…the most commonly reported side effects were tiredness, diarrhea, and changes of appetite/weight…

Iffland, K., & Grotenhermen, F. (2017). An update on safety and side effects of cannabidiol: a review of clinical data and relevant animal studies. Cannabis and cannabinoid research, 2(1), 139-154.

Final Thoughts

Finally, despite the benefits of using CBD, there is still known risk associated with the use of CBD. CDB users must consult with their doctors beforehand to know if they are safe from the risk listed above. In the current legal state of US CBD, consumers are solely responsible for the risk they take in using CBD.

Retail CBD products are not evaluated for safety or effectiveness and do not guarantee any particular effect or result. CBD is a buyer beware market and will continue to be until the FDA regulated it properly. Currently, there is not even a way for CBD companies or customers to report and track adverse events and no legally approved labeling jargon to communicate risks to consumers.