Cannabis sativa plant. This plant, which contains more than 80 chemicals known as cannabinoids, is also called marijuana or hemp. Two key ingredients in cannabis are CBD and tetrahydrocannabinol (THC). THC is responsible for the intoxicating effects of cannabis, and it might contribute to the plant's health benefits. Unlike THC, CBD is not intoxicating.
CBD is available in softgels, tablets, capsules, oils, gums, liquid extracts, and vape juice (for fillable electronic cigarettes). Some of these products contain CBD only, and others contain CBD in combination with other ingredients.
A 2017 study concluded that labels of many products containing CBD make inaccurate claims about the amount of CBD in the product, and CBD concentrations in the same product sometimes vary. Moreover, THC (or marijuana) was found in 21% of the products (1).
(See also Overview of Dietary Supplements.)
Claims
Prescription CBD is used for treatment of certain seizure disorders.
Some people use CBD to treat many other health problems, including the following:
Bipolar disorder
Pain
Anxiety
Crohn disease
Diabetes
Sleep problems
Multiple sclerosis
Evidence
Oral CBD has been approved by the US Food and Drug Administration (FDA) for the treatment of seizures associated with two epileptic encephalopathies: Lennox-Gastaut syndrome and Dravet syndrome. These epileptic encephalopathies start in childhood and involve frequent seizures along with severe impairments in cognitive development. Two clinical studies have reported on the effectiveness of CBD in these patients and other patients with treatment-resistant epilepsies (2, 3). However, not enough research has been done on cannabinoids for other, more common forms of epilepsy to determine if they are helpful for these conditions.
A 2018 Cochrane systematic review on cannabis‐based medicines for chronic neuropathic pain in adults included 16 studies with 1750 participants (4). The analysis showed that cannabis‐based medications may increase the number of people achieving 50% or greater pain relief compared with placebo (21% versus 17%). Cannabis-based medications probably increase the number of people achieving pain relief of 30% or greater compared with placebo (39% versus 33%). The authors concluded that this small improvement in neuropathic pain might be outweighed by the potential harms.
There are numerous clinical studies regarding the uses of CBD for various symptoms and disorders summarized on the National Institutes of Health (NIH) website.
Adverse Effects
CBD can have adverse effects such as dry mouth, low blood pressure, diarrhea, decreased appetite, mood changes, light-headedness, fatigue, rash, insomnia and poor quality sleep, and sleepiness.
CBD can cause increased transaminases and liver injury.
Drug Interactions
CBD is metabolized by the cytochrome p450 (CYP) enzymes CYP3A4 and CYP2C19. Coadministration with medications that are metabolized by or inhibit CYP3A4 or CYP2C19 can increase plasma concentrations of these medications or of CBD, which may result in increasing their effects and a greater risk of adverse reactions (5).
CBD may increase the serum concentration and effects of a number of drugs including the following:
Tricyclic antidepressants
Tricyclic antidepressants may increase serum concentrations of CBD and thus may increase adverse effects of CBD.
(See also table Some Possible Dietary Supplement–Drug Interactions.)
References
1. Bonn-Miller MO, Loflin MJE, Thomas BF, et alJAMA 318(17):1708-1709, 2017. doi:10.1001/jama.2017.11909
2. Szaflarski JP, Bebin EM, Comi AM, et alEpilepsia 59(8):1540-1548, 2018. doi:10.1111/epi.14477
3. Szaflarski JP, Bebin EM, Cutter G, et alEpilepsy Behav 87:131-136, 2018. doi:10.1016/j.yebeh.2018.07.020
4. Mucke M, Phillips T, Radbruch L, Petzke F, Hauser W: Cannabis-based medicines for chronic neuropathic pain in adults. Cochrane Database Syst Rev 3(3):CD012182, 2018. Published 2018 Mar 7. doi:10.1002/14651858.CD012182.pub2
5. Balachandran P, Elsohly M, Hill KPJ Gen Intern Med 36(7):2074-2084, 2021. doi:10.1007/s11606-020-06504-8
More Information
The following English-language resource may be useful. Please note that THE MANUAL is not responsible for the content of this resource.
National Institutes of Health (NIH), National Center for Complementary and Integrative Health: Cannabis (Marijuana) and Cannabinoids: What You Need To Know
