A Doctor’s View: What the Scientific Evidence Shows About CBD Oil—Part 2
By Dr. Karen Keough, Chief Medical Officer
In this special three-part series, Compassionate Cultivation Chief Medical Officer Dr. Karen Keough discusses the important role Texas physicians play in the medical cannabis program and the impact this has on patients—from prescribing CBD oil, to research findings and the future of the program.
In a recent blog post, I outlined apprehensions that some of my fellow Texas neurologists have in regard to the potential legal and professional risks associated with prescribing CBD medicine: low-THC, high-CBD medical-cannabis products.
In this post, I want to discuss another source of resistance: The perspective that there is limited research proving the efficacy of medical cannabis.
It’s no surprise that we could use more disciplined research in this arena. The current situation is a direct result of the Schedule I federal status of cannabis and the resulting barriers to comprehensive clinical study of cannabis-oil extracts and other products available in states that have approved medical cannabis. It’s a Catch-22, to be sure.
The facts are that the only currently available pharmaceutical containing CBD is Epidiolex, a drug manufactured by London-based GW Pharmaceuticals, which the U.S. Food and Drug Administration approved exclusively for patients with Dravet syndrome or Lennox-Gastaut syndrome. Low-THC, high-CBD cannabis oil extracts produced by state-regulated medical cannabis companies such as Compassionate Cultivation have not yet been approved by the FDA.
Yet, while physicians are certainly most accustomed to prescribing FDA-approved pharmaceuticals, the reality is that we recommend a lot of things that aren’t FDA-approved—based on the evidence that they do meet reasonable standards of safety and efficacy.
Common examples include things such as melatonin, omega fatty acids and vitamin D for migraine prevention, all of which are not FDA-approved for a specific indication. Rather, they are supplements that have demonstrated varying levels of efficacy in smaller scale trials.
In the case of CBD therapy for epilepsy, we have an unusual advantage of high-level evidence of safety and efficacy that led to FDA approval in three randomized, placebo-controlled trials of Epidiolex. And here is what we currently know: There is clear and undeniable medical evidence for efficacy of CBD in the treatment of refractory epilepsy, and there are high expectations for tolerability and safety.
Some physicians may say, “Well, OK, what’s coming out of the United States is not Epidiolex,” but the similarities are such that we can make a sensible argument for the use of state-regulated CBD products. From a chemical standpoint, the ingredients in Epidiolex are quite similar to regulated Texas medical-cannabis products. Epidiolex has 10% CBD by weight, which up to now has been the minimum required concentration of CBD in the Texas Compassionate Use Program (CUP). Epidiolex contains virtually no THC whatsoever, whereas regulated CUP products are limited to a maximum of 0.5 percent THC. Based on the Epidiolex trials, we know that CBD alone can reduce seizures. So, the expectation that seizure reduction would be generalizable to Texas medical-cannabis products is a fairly reasonable conclusion.
The differential effects of low-concentration of THC are not answerable from Epidiolex trials, and must be assessed from a growing body of evidence that demonstrates its safety and efficacy. With broader availability of both types of products across the medical community, we will learn much more about this from patients who have been utilizing CBD formulations that contain THC.
Meanwhile, researchers are documenting and categorizing research on CBD and other cannabinoids for their potential to relieve ailments such as chronic pain; spasticity related to multiple sclerosis and other neurological conditions; anxiety; and many others. This includes a landmark 2017 report by The National Academies of Sciences, Engineering and Medicine (NASEM) that examined 10,000 study abstracts conducted since 1999 and noted whether research evidence was conclusive or substantial—or otherwise moderate, limited or insufficient. I encourage my fellow physicians to explore the NASEM report and other recent studies.
And as the state’s Compassionate Use Program progresses, physicians are accumulating valuable data of their own about state-regulated CBD oil and how it’s working for patients.
In my own practice, I have been tracking patient outcomes and am happy to consult with colleagues about my findings. It’s critically important for physicians participating in the Texas program to work together for the advancement of knowledge about CBD medicine.
Check back for part three of this series, where I will continue examining the physician’s important role in medical cannabis treatment programs, and I’ll address why fear of the unknown is causing hesitation among Texas physicians.