CBD oil laws vary by state. In Tennessee, legislators first passed HB 2144 allowing citizens to possess concentrated CBD oil (with a THC concentration of no more than 0.9%) if they have a “legal order or recommendation” and a diagnosis of irretractable seizures or epilepsy. Most recently, Tennessee legislators have passed HB 1164. This allows consumers with no “legal order or recommendation” to purchase CBD oil products over the counter with no more than 0.3% THC.1
In one study, 84 CBD products were tested to confirm the concentration of CBD reported on the label. Approximately 26% of the products contained less CBD than labeled, and 46% of the products contained more CBD than labeled. When combined with vague regulations from the FDA, the actual contents including inactive and active ingredients in CBD oils may be grossly underreported on the labeling.2
Another study demonstrated that CBD did not influence patient hemodynamics or vitals but did carry a risk for CYP enzyme inhibition and induction. In their research, the authors found CBD to inhibit CYP2D6 and CYP2C9, while inducing CYP3A4. Up to 60% of pharmaceutical drugs are metabolized through CYP3A4. The induction of CYP3A4 may result in more rapid metabolism of the drug and therefore, increase drug concentrations. This could cause potentially harmful effects for patients with multiple drug therapies for chronic illness.3
There are many reasons to be cautious with CBD oil. From potential pharmaceutical drug interactions to poor regulation and potential contaminants (including elevated misreported amounts of THC that could cause a patient to test positive for THC), the real dangers of over the counter CBD oil are somewhat unknown. Risk versus benefit should always be a topic of discussion with patients when considering OTC adjunct therapies.4
Prepared by Dr. Nena Bowman, PharmD, DABAT, Managing Director, Tennessee Poison Center.
- Bonn-Miller DOI: 10.1001/jama.2017.11909
One of our loyal readers sent us the above question. He said that a number of patients using CBD oil products for depression reported psychoactive effects such as drowsiness and reduced anxiety. He asked about the products in CBD oil and if CBD oil should be discontinued when patients are being treated for depression. What a good question. As you can see by the response from Dr. Bowman, CBD oil certainly can increase or decrease the serum drug concentration of the pharmaceuticals the patient may be taking for depression. It is difficult to answer with a “Yes” or “NO” to the question of discontinuation of CBD oil. However, understanding the potential interaction can help one to make an informed decision. -ds
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Donna Seger, MD
Tennessee Poison Center
Poison Help Hotline: 1-800-222-1222