Studies on CBD Oil & Epilepsy [Research Simplified]

Epilepsy is considered to be a common neurological disorder, characterized primarily by sudden bouts of seizures and convulsions.

It is so common that it, in fact, affects around 50 million people worldwide each year, or at least, that’s what the World Health Organization (WHO) estimates. According to their data, this neurological condition affected around 1.2% of the American population in the United States in 2015 alone.

Not only is its incidence so common, but it is also a misunderstood disorder, owing mostly due to the confusion over its actual causes and misleading symptoms. Apart from seizures and convulsions (that is not accompanied by fever), epilepsy may also cause:

Often the normal course of treatment or rather the conventional forms of treatment fail to help these patients. Moreover, the conventional methods also come at a price – not by just a pinch to the pocket, but also with adverse side effects for the patients.

Perhaps this is why for the first time on June 25, 2018, the US Food and Drug Administration (FDA) approved [2, 11] Epidiolex [*1], an oral solution containing cannabidiol (CBD), for the treatment of seizures caused by two specific types of epilepsy — Lennox-Gastaut syndrome (LGS) and Dravet syndrome – among patients who are at least 2 years of age.

The drug’s approval was based on three clinical trials, involving 516 patients with either of the syndromes. The trials showed a positive effect on patients who took Epidiolex. There was a significant drop in the number of seizures they experienced compared to those who took a placebo.

Incidentally, this is the first drug approved by the FDA to treat seizures associated with Dravet syndrome.

The CBD oral solution, Epidiolex, is a drug that is extracted from the marijuana plant, which is probably the most controversial and oft misunderstood source of medicine and food supplement. FDA approved this medication for adults and children above the age of 2 years only in cases when the usual medications have no positive impact on the patients.

However, it has been seen that CBD oil is effective on epileptic seizures only when taken alongside the standard anti-epilepsy medications. No clinical trials have been conducted on epilepsy patients to assess the impact on CBD oil alone.

The confusion over the causes of epilepsy

Our brain is wired to send and receive messages according to stimuli received from our environment and controls our bodily functions with the help of neurotransmitters. Epilepsy is believed to be caused by the faulty and erratic transmission of messages to and from the brain, leading to uncontrolled physical movements that could be coupled with lapses in consciousness.

In most cases, epilepsy is believed to be congenital, i.e., either it was genetically inherited or caused due to prenatal complications, like brain damage due to lack of oxygen. That is why it is often manifested within the first two years of a child’s life. However, it may also develop later on in life due to some traumatic head injury, stroke, or infectious diseases, such as AIDS and viral encephalitis. This usually appears after the age of 60-65 years.

What’s amiss in the conventional methods of treatment

Most types of epilepsy are not curable. However, it is treatable by means of either surgery (if it is caused by a correctable brain condition) or medication. Most of these medications basically target the key symptoms, like seizures.

The most common anti-epileptic drugs (AEDs) are:

But these medications come with quite a few side effects – from drowsiness and dizziness to even depression and suicidal tendencies.

Often patients are found to be immune to the intended effects of prescribed medicine, forcing doctors to recommend another medication, and so on.

In the process, the patient experiences all the adverse side effects of the medicines that have already been prescribed to him or her.

This is the reason why there is so much interest among the medical fraternity as well as patients across the US about cannabidiol’s effectiveness [7, 8] in treating epilepsy.

What does science say about CBD for epilepsy?

Although, it isn’t completely clear why CBD seems to reduce seizures among epilepsy patients, what we do know is that cannabinoids have a biochemical impact on the nerve cells that control movement, among other functions, in both humans and animals. Research and clinical tests on its impact are still ongoing.

Currently, oral CBD solution may only be recommended for controlling seizures associated with LGS and Dravet syndrome, and not for treating any other type of epilepsy.

It has been seen that when taken with other anti-seizure medications, CBD reduces the frequency and severity of seizures substantially in epilepsy patients.

Among these patients, aged between 2 to 55 years, 76 patients were given 20 mg CBD oil per kilogram of body weight, 73 were given 10 mg CBD oil per kilogram of body weight, while 76 were given placebo – all for 14 weeks.

During the course of treatment, it was seen that there was a 41.9% drop in seizures among the 20-mg CBD oil group of patients, while the drop was by 37.2% in the 10-mg CBD group. The placebo group showed a drop in seizures by 17.2%. [Note that all these patients were also taking their regular pharmaceutical medication.]

However, the researchers concluded that the 20mg dose may be a bit too much for some patients, as 6 out of the 76 patients taking this dosage left the clinical trial owing to side effects, which included sleepiness, diarrhea, and loss of appetite.

The test results showed that 43% of patients taking CBD experienced a 50% decrease in the frequency of convulsive-seizures, while 27% of patients taking placebo displayed the same dip in frequency of seizures, owing mostly to the standard anti-epilepsy drugs which were being administered to all patients.

However, there was no significant improvement in the frequency of non-convulsive seizures.

Around 3% of patients in this test stopped taking CBD due to some side effects that included diarrhea, vomiting, fatigue, fever, sleepiness, and abnormal results on liver function tests.

Besides, some research has also suggested that CBD can help treat complications arising from epilepsy, like neuro-degeneration, neuronal injury, and psychiatric diseases.

Several clinical tests [12] to examine the efficacy of CBD on epilepsy patients are still going on. Hopefully, CBD oil will soon become legally available for the treatment of more types of epilepsy in the near future.

Situations when CBD isn’t safe for epilepsy patients

While Epidiolex has been proved to be suitable for treating two specific types of epilepsy – LGS and Dravet Syndrome – there are some situations when it has been noticed to be not suitable for epileptic patients.

Studies show benefits may fade with time:

The effect of CBD liquid, which has proven effective against seizures in most cases, seems to dull in about one-third of patients, who develop tolerance towards the drug. This was revealed by a study, presented at the American Epilepsy Society’s annual meeting in New Orleans on December 2, 2018.

In this study, 92 children and young adults (aged of 1 and 37 years) suffering from treatment-resistant seizures were administered cannabis oil extract, containing 20:1 CBD-to-THC ratio, for an average of 19.8 months. It was seen that 32.6% of patients developed tolerance to CBD, reported Shimrit Uliel-Sibony, MD, head of the pediatric epilepsy service at Tel Aviv Sourasky Medical Center’s Dana-Dwek Children’s Hospital in Israel.

Interaction with other drugs:

In the course of research to study the effectiveness of CBD oil in treating epilepsy syndromes, scientists have noticed some drug-to-drug interactions. It was revealed:

Any oil-based product, even placebos, can cause these side effects. So, any epilepsy patients, previously or currently suffering from stomach problems would do well to stay away from CBD oil altogether.

Editor’s Takeaway

CBD oils and related products have different dosages and health benefits. Although CBD may seem to have the potential to help manage a variety of conditions, never buy any product without proper research.

As far as epilepsy is concerned, Epidiolex is expected to pave the way for more FDA-approved CBD products for other forms of epilepsy and their associated seizures in the future. While there are many unregulated CBD products in the market, we can only hope to see more clinical trials and many more good results soon.

Meanwhile, as patients or caretakers of patients with epilepsy, we need to stick to the standard methods of epilepsy treatment and only abide by what the doctor prescribes.

If you or someone close to you is suffering from the two specific types of epilepsy, LGS or Dravet Syndrome, for which Epidiolex has been approved, you can ask your doctor if he deems it necessary for you to try out this drug.

But remember: NEVER self-medicate an epilepsy patient!

*1. Epidiolex is produced by Greenwich Biosciences, a US subsidiary of UK-based company GW Pharmaceuticals, which also produces Sativex, another CBD-based product.

  1. Epidiolex as an adjunct therapy for the treatment of refractory epilepsy: a comprehensive review with a focus on adverse effects; F1000Research Review; Krithiga Seka;
  2. FDA Briefing Document; Peripheral and Central Nervous System Drugs; Advisory Committee Meeting; April 19, 2018;
  3. Effect of Cannabidiol on Drop Seizures in the Lennox–Gastaut Syndrome; The New England Journal of Medicine; May 17, 2018; Orrin Devinsky, M.D., Anup D. Patel, M.D., J. Helen Cross, M.B., Ch.B., Ph.D., Vicente Villanueva, M.D., Ph.D., Elaine C. Wirrell, M.D., Michael Privitera, M.D., Sam M. Greenwood, Ph.D., Claire Roberts, Ph.D., Daniel Checketts, M.Sc., Kevan E. VanLandingham, M.D., Ph.D., and Sameer M. Zuberi, M.B., Ch.B., M.D. for the GWPCARE3 Study Group*;
  4. Trial of Cannabidiol for Drug-Resistant Seizures in the Dravet Syndrome; The New England Journal of Medicine; Orrin Devinsky, M.D., J. Helen Cross, Ph.D., F.R.C.P.C.H., Linda Laux, M.D., Eric Marsh, M.D., Ian Miller, M.D., Rima Nabbout, M.D., Ingrid E. Scheffer, M.B., B.S., Ph.D., Elizabeth A. Thiele, M.D., Ph.D., and Stephen Wright, M.D. for the Cannabidiol in Dravet Syndrome Study Group*; May 25, 2017;
  5. Cannabidiol in patients with treatment-resistant epilepsy: an open-label interventional trial; Lancet Neurology; Dec 24, 2015; Devinsky O, Marsh E, Friedman D, Thiele E, Laux L, Sullivan J, Miller I, Flamini R, Wilfong A, Filloux F, Wong M, Tilton N, Bruno P, Bluvstein J, Hedlund J, Kamens R, Maclean J, Nangia S, Singhal NS, Wilson CA, Patel A, Cilio MR.;
  6. CBD-enriched medical cannabis for intractable pediatric epilepsy: The current Israeli experience; Seizure; Jan 6; 2016; Tzadok M1, Uliel-Siboni S2, Linder I3, Kramer U2, Epstein O4, Menascu S2, Nissenkorn A5, Yosef OB5, Hyman E4, Granot D6, Dor M7, Lerman-Sagie T3, Ben-Zeev B5;  
  7. Cannabinoids in the Treatment of Epilepsy: Hard Evidence at Last?; Journal of Epilepsy Research; Dec 31, 2017; Emilio Perucca;
  8. Cannabidiol for Treatment of Childhood Epilepsy–A Cross-Sectional Survey; Frontiers in Neurology; Sep 7, 2018; Kerstin A. Klotz, Andreas Schulze-Bonhage, Victoria San Antonio-Arce, and Julia Jacobs;
  9. The Use of Cannabis to Treat Children with Epilepsy; Epilepsy Foundation of Colorado; March 2014;
  11. Epilepsy Foundation Statement from President and CEO Philip Gattone on the U.S. Food & Drug Administration’s Approval of EPIDIOLEX®; Epilepsy Foundation; Monday, June 25, 2018;
  12. Epilepsy Foundation; Find a Clinical Trial;
  13. Efficacy and Safety of Cannabidiol in Epilepsy: A Systematic Review and Meta-Analysis; Drugs. Nov 2018; Lattanzi S, Brigo F, Trinka E, Zaccara G, Cagnetti C, Del Giovane C, Silvestrini M;
  14. Epilepsy and Cannabis: A Literature Review; Cureus. September 2018,  Monitoring Editor: Alexander Muacevic and John R Adler;