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CBD Reduced Epileptic Seizures in Patients, but with Increased Side Effects

By Leo Bear-McGuinness

Published: Nov 27, 2018   
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Children with epilepsy syndromes experience far fewer seizures when given cannabidiol (CBD), a study has shown.

The research, which was carried out by an international team of Austrian, Italian and Swiss scientists, showed that child patients with Lennox-Gastaut syndrome (LGS) and dissociative seizures (DS) experienced fewer seizures when given CBD over placebos.

However, the children given the CBD treatment also experienced more adverse events, such as decreased appetite and diarrhea.

Approximately one-third of epilepsy patients regularly experience seizures even with treatment from other medicines. For many sufferers, a more effective medicine is desperately needed.

While many are calling CBD-derived medicines a solution to childhood epilepsy issues, this study shows that such drugs might not be without their side effects.

CBD and epilepsy

It’s been estimated that around 50 million people live with epilepsy, making it one of the most common neurological diseases in the world. While severity differs between individuals, many still struggle with daily tasks such as driving, and in severe cases, a person’s quality of life can become so low that they then suffer from further illnesses such as depression.

The actual seizures typical of epilepsy are caused by irregular electrical discharges within brain cells. These misfires result in body convulsions and loss of consciousness, which can lead to physical harm.

Lennox-Gastaut syndrome is a rare form of epilepsy that occurs in 1-5 in every 100 epileptic children. Although uncommon, it is widely regarded as the most difficult to treat of all epilepsy conditions.

Seizures can vary, but the most common type is an atonic seizure or ‘drop attack’. During these episodes, which could happen multiple times a day, the child will suddenly fall to the ground, causing shock and injury.

Known treatments include sodium valproate, lamotrigine, and phenytoin, but none are proven to be wholly successful.

CBD, on the other hand, has been found to be an effective treatment for a variety of seizure models.

After all, for decades research has shown that endocannabinoids play an important role in the control in synaptic transmission of neuronal firing. And in recent times, many observations have been made which have implicated a role of endocannabinoid systems in epilepsy, such as a demonstration of downregulation of CB1 receptors and related molecular components in glutamatergic neurons from surgical samples of an epileptic human hippocampus.

CBD’s anti-seizure properties aren’t just related to its effect on cannabinoid receptors. In fact, a multitude of mechanisms that include the agonist and antagonist effects on ionic channels, neurotransmitter transporters, and multiple 7-transmembrane receptors all act as mediators between the drug and its calming effects.

Medical evidence for CBD’s efficacy in reducing epileptic seizures is so strong that many doctors now prescribe the drug to epileptic patients in states and nations where it is prohibited. Indeed, the UK government’s recent decision to allow the use of medicinal cannabis was partly driven by large media focus on two severely epileptic children and their struggles to access any effective medicine.

CBD side effects

To better understand the efficacy and safety of CBD as a treatment for patients with epilepsy, the research team set up several randomized, placebo-controlled trials. Over 500 participants who suffered from Lennox–Gastaut syndrome (LGS) and Dravet syndrome (DS) were unknowingly given oral CBD or a placebo.

The results were promising but peppered with negative side effects.

For example, seizure frequency was reduced by at least 50% in 37.2% of the patients in the group given 20 mg of CBD, and 21.2% of the placebo-treated participants. So, while CBD did reduce seizures in a number of participants, a fifth of patients still had a significant seizure reduction rate even though they hadn’t taken any medicine.

But while seizure rates were reduced for many participants, many other measurements increased. Symptoms of drug withdrawal occurred in 11.1% and 2.6% of participants receiving CBD and placebos, respectively, which, unsurprisingly indicates that CBD had a stronger effect.

Treatment was also discontinued in 8.9% of CBD-fed patients due to increased adverse events such as diarrhea. In comparison, only 1.8% of placebo patients were removed from their respective trial.

With or without the need to remove patients from the trial, adverse events occurred in 87.9% and 72.2% of patients treated with CBD and placebos. If these exceptionally high figures were only present in the patients who took CBD, it would be reasonable to assume the drug was causing the adverse effects. However, as over 70% of the placebo patients also received these negative side effects, it’s difficult to draw absolute conclusions.

CBD, Lennox–Gastaut syndrome and inconclusive results

On the surface, the researchers’ study showed that CBD is a more effective treatment for Lennox–Gastaut syndrome than placebos. After all, patients who took the oral CBD experienced fewer seizures; this conclusion that falls in line with previous research into the calming and anticonvulsive effects of CBD.

However, the results didn’t always cast CBD in a favoring light. Many of the recorded figures showed how the drug caused symptoms of drug withdrawal and higher rates of adverse side effects such as drowsiness, a decreased appetite, and diarrhea. And perhaps even worse, the figures from the placebo trial weren’t far behind. A substantial number of patients who didn’t consume any CBD also saw a decrease in seizure rates and an increase in adverse effects.

As both the use of medicinal cannabis and the scientific studies around it continues to grow worldwide, more evidence of cannabis’ effects on epileptic conditions is collected every year. While the results of this particular study downplay the value of CBD in epilepsy treatment, more research is still needed to create a conclusive view on the drug’s efficacy.

Leo Bear-McGuinness

Science Writer & Editor

Leo joined Analytical Cannabis in 2019. From research to regulations and analysis to agriculture, his writing covers all the need-to-know news for the cannabis industry. He holds a Bachelor's in Biology from Newcastle University and a Master's in Science Communication from the University of Edinburgh.


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