Particularly with legalization of marijuana and increasing use of medical marijuana, a buzz has developed about CBD oil and many patients are asking their primary care providers about using it for various medical conditions. It can be challenging to know how to answer many of the questions, but it helps to be as up-to-date as possible on what is known.
CBD oil or cannabidiol oil is one of 113 active compounds found in cannabis. It accounts for up to 40% of the plant’s extract, depending on which strain is being grown.
The reason there is interest in potential medical properties of this compound is that it appears to not have the psychoactive (or “high”) effects such as those caused by tetrahydrocannabinol (THC). There is thought that CBD oil might have a down regulating effect on disordered thinking and anxiety and even might be neuroprotective. This is very different than THC’s effects on the brain – long-term use has been shown to have detrimental effects on IQ and executive function.
It is currently being studied for treatment for addiction, chronic inflammatory and neuropathic pain syndromes, and epilepsy. Currently, most of these studies are small and involve animal subjects.
People using CBD oil can experience side effects, such as somnolence, diarrhea, vomiting, fatigue, and abnormal liver function. There are also possible drug interactions to be aware of, like an interaction with valproate. There is evidence that CBD can reduce THC clearance, which can increase the THC effects in a dose-dependent manner. It is important to help patients considering using these products to be aware that even “natural supplements” can have adverse effects and drug interactions. Many people are not aware of this and assume if something is “natural” that it cannot have side effects on interact with their other prescribed medications.
Recreational marijuana typically has a lower relative concentration of CBD and higher relative concentration of THC because users prefer cannabis strains that are more mind-altering. Medical marijuana standards are not very strict, but in general require lower relative THC concentration and higher relative CBD concentration. Still it will be important to distinguish between medical marijuana (which would still have THC and therefore can have psychoactive properties and have negative effects on brain function) and medical CBD oil. Any part of a cannabis plant that has a THC concentration of 0.3% or less is referred to as industrial hemp. Typically CBD extract is made from industrial hemp and therefore has a very low THC concentration.
Another challenge is that CBD products are not regulated by the FDA or any authorizing agency. Many companies are adding CBD oil to food items and claiming neuroprotective features for those products. There is no standardization on the amount of CBD in a product or the bioavailability of the active ingredient. The only limitation for referring to a product as CBD is that there is a restriction on the amount of THC in the product.
The take home messages are that there is still a lot to be learned about the role that CBD could play in medicine. More research is being conducted now that marijuana has been legalized in many states and there is more and more public pressure to understand the possible medical benefits of cannabis. It is important for primary care providers to maintain the vow to first “do no harm” by strongly recommending against using cannabis that is high in THC, recommending avoiding cannabis use in general until adulthood, and avoiding daily use.