PEOPLE EXPERIENCING epilepsy and their families have been waiting for a marijuana-based drug to become available by prescription. On June 25, a major step was taken in this direction when the Food and Drug Administration approved marijuana-based cannabidiol, or CBD, for treatment of seizures in two rare forms of severe childhood-onset epilepsy in patients 2 years of age and older. The twice-daily CBD oral solution, brand name Epidiolex, is expected to be available through pharmacies by this fall. The approval was based on a stringent review of results from three clinical trials involving over 500 children and adults with either Lennox-Gastaut syndrome or Dravet syndrome. Patients were randomly divided into groups, and then the results in each group were compared after a period of treatment with either CBD or a placebo (a sham treatment that looked like CBD but contained no active ingredients). The researchers and patients were "blinded" and kept unaware of which patients were in which groups. These randomized, double-blind, placebo-controlled studies followed strict guidelines to prevent patient or researcher bias from skewing the results. The results with CBD treatment were significantly better than those with placebo, demonstrating that the drug is effective. Patients with Lennox-Gastaut syndrome who received CBD experienced a 37 to 42 percent reduction in drop seizures, the type with muscle stiffening or limpness affecting the body, trunk or head, which causes or predisposes a person to falling. In patients with Dravet syndrome, a 50 percent or greater reduction in convulsive seizures was seen in 43 percent of patients treated with CBD, compared to 27 percent of patients in the placebo group. Safety of CBD was also carefully analyzed in the studies. When patients had side effects, the most common were tiredness, lethargy and sleepiness. A few people had decreased appetite, vomiting, diarrhea or unsteadiness. Blood tests showed mild liver abnormalities in some patients, especially if they were also taking the seizure drug valproate (Depakote), but test results returned to normal when the CBD was discontinued. CBD had some interactions with other seizure medications. For example, it increased the level in the bloodstream of one of the active breakdown products of the seizure drug clobazam (Onfi), and this sometimes resulted in sleepiness. A few other seizures drugs were also mildly affected by CBD, but the impact was insignificant. Unlike marijuana, CBD does not contain tetrahydrocannabinol, or THC, the intoxicating chemical that causes marijuana's "high." Because the THC has been removed, CBD is believed likely to entail a low risk for addiction or abuse. The U.S. Drug Enforcement Administration will soon formally reclassify CBD into a category with other drugs that have federal approval for medical use. It should be noted that the FDA approved only one specific marijuana-based medication for a specific use. When CBD becomes available in pharmacies, its manufacturer will provide doctors and families with detailed information and guidance for its use. This is in contrast with other marijuana-based products, which have not been through a similar rigorous FDA approval and quality-controlled manufacturing process. Patients and families may ask about CBD for treatment of epilepsy conditions other than Lennox-Gastaut syndrome or Dravet syndrome. While physicians can legally prescribe FDA-approved drugs for conditions other than those studied in the clinical trials, the "off-label" use of medications requires careful consideration and specialized medical expertise. Further research will be important to clarify the range of patients who may benefit from treatment with CBD. Source
