The US Food and Drug Administration has approved the first prescription drug derived from marijuana for treating two rare and severe forms of epilepsy.
Epidiolex has been approved for treating seizures associated with Lennox-Gastaut syndrome or Dravet syndrome in patients aged 2 years or older.1 These forms of epilepsy are frequently resistant to currently available treatments.
The oral solution, developed by the UK based company GW Pharmaceuticals, contains purified cannabidiol (CBD), a chemical component of the Cannabis sativa plant. However, CBD does not cause the intoxication or euphoria that comes from tetrahydrocannabinol (THC). Before the drug can be marketed the Drug Enforcement Administration must reclassify cannabidiol: it is currently considered a schedule drug, meaning that it has no medical value and a high risk of misuse.
Epilepsy is one of the most common neurological disorders in the US. Nearly 3 million Americans have been diagnosed with the condition. 1 in 26 people will develop the condition in his/her lifetime. It is associated with abnormal electrical activity in the brain. This means some type of sensory disturbance, loss of consciousness or seizures. Atonic or “drop seizures” are just like they sound and are characterized by a loss of muscle control. The person can suddenly fall, resulting in injury as the person strikes objects in the immediate surrounding or by contact with the ground.
An article in theNew England Journal of Medicine explored the potential for CBD combined with current medicine therapies to help patients with Lennox–Gastaut syndrome, a severe form of epilepsy characterized in part by frequent drop seizures. The outcome was promising.
The Lennox–Gastaut syndrome is a severe developmental epileptic encephalopathy that has multiple causes and an incidence of approximately two cases per 100,000 population. The disorder is characterized by several seizure types, severe cognitive impairment, and an abnormal electroencephalographic pattern of slow spike-and-wave complexes. Seizures usually begin to occur before the age of 8 years and persist into adulthood in more than 90% of patients. Drop seizures due to an increase in (tonic) or loss of (atonic) motor tone are characteristic of this disorder and often result in serious injury. Six medications are approved to treat seizures in patients with this syndrome. Despite treatment, disabling seizures continue to occur in most patients.
The patient groups who received 10 mg and 20 doses along with their current anti-seizure medication experienced a reduction in the monthly occurrences of drop seizures. A few participants did experience side effects such as sleepiness, loss of appetite and diarrhea. For seven of them, the side effects were significant enough for them to feel the need to drop out of the study. Another side effect worth further study was the increase in some patients’ liver aminotransferase concentration, an enzyme used as a marker of a healthy or stressed liver.
Yet that is the only prescription drug derived from the actual cannabis plant to go through the FDA approval process, which means it went through clinical trials to determine its efficacy and safety just like any other drug on the market. Three other drugs based on synthetic forms of delta-9- tetrahydrocannabinol (THC) have also been approved: Marinol and Syndros for the treatment of anorexia associated with weight loss in AIDS patients, as well as a drug called Cesamet.
The FDA does not take sides when it comes to approving a particular drug. If the data shows that a new drug is safe and effective, then there is no reason to stop an FDA approval. So why have so few drugs made it to market? The issue is with other federal agencies, such as the Drug Enforcement Agency (DEA) and the National Institute for Drug Abuse (NIDA). And there lies the problem.
This study was paid for by GW Pharmaceuticals, a leader in the field of cannabis research. The British company brought Sativex to the market and hope to be the first FDA approved maker of plant-derived CBD under the trade name Epidiolex. If approved, prescription CBD could be another tool used by physicians throughout the US to provide additional relief to patients suffering from seizures.