The US Food and Drug Administration (FDA) has approved GW Pharmaceuticals’ Epidiolex, which contains an active ingredient derived from marijuana. The drug is the first containing the substance to be permitted for sale in the US. It is also the first-ever approval of a drug specifically for Dravet syndrome patients.

Containing CBD, a chemical component of the Cannabis sativa plant, Epidiolex was also approved for treatment of another rare and severe form of epilepsy, Lennox-Gastaut syndrome.  Both syndromes appear in early childhood, Dravet develops in the first year of life and Lennox-Gastaut a few years later, typically between the ages of three and five. Both are characterized by severe seizures, with Dravet requiring emergency medical care.

Although the GW product contains CBD – only one of more than 100 chemicals found in marijuana – it does not contain tetrahydrocannabinol (THC), the element responsible for the “high” associated with smoking. Patients who take Epidiolex should not experience psychoactive side effects, according to neurologists.

The new drug was studied in three randomized, double-blind, placebo-controlled clinical trials involving 516 patients. When taken in combination with other medications, it is said to have demonstrated effectiveness in reducing the frequency of life-altering seizures when compared with the placebo.

Obtaining the marijuana-based drug could be complicated for some patients, news reports said. Despite an increase in the number of states that allow medical marijuana, the US government continues to classify it as a controlled substance with no medical use – a categorization it shares with heroin and LSD. Nevertheless, the approval of Epidolex is seen as potentially opening the door for a number of other marijuana-derived treatments.

“Epidiolex is essentially a pharmaceutical-grade version of CBD oil, a product already commonly used to treat afflictions like seizures,” said Elaine Wirrell, director of the Mayo Clinic's program for childhood epilepsy. The FDA’s recognition and regulation of such medications is crucial, she said, because the commercially produced drug will not only be cheaper, but its contents will be known. “In the artisanal products, there's often a huge variation in doses.”

FDA Commissioner Scott Gottlieb commented that the approval is “a reminder that advancing sound development programs that properly evaluate active ingredients contained in marijuana can lead to important medical therapies. The FDA is committed to this kind of careful scientific research and drug development,” he said.