potassium channels. Stiripentol also improves the effectiveness of many other anticonvulsants, possibly due to its inhibition of certain enzymes, slowing the drugs' metabolism and increasing blood plasma levels. Chemistry Stiripentol is an α-ethylene alcohol; its chemical formula is 4,4-dimethyl-1-[3,4-(methylendioxy)-phenyl]-1penten-3-ol. It is chiral and used medically as the racemate. The R enantiomer appears to be around 2.5 times more active than the S enantiomer. History Stiripentol was discovered in 1978 by scientists at Biocodex and clinical trials started over the next few years. It was originally developed for adults with focal seizures, but failed a Phase III trial. In December 2001, the European Medicines Agency (EMA) granted stiripentol orphan drug status (designation number EU/3/01/071) for the treatment of severe myoclonic epilepsy of infancy (SMEI, also known as Dravet's syndrome) in children and in January 2007, the EMA granted the drug a marketing authorisation for use of the drug as an add-on to other anti-seizure drugs. It was approved in Canada for this use in May 2013. As of 2017, it was also approved for this use in Japan. In August 2018, stiripentol was approved by the US Food and Drug Administration (FDA) as an adjunctive therapy for Dravet Syndrome. Society and culture Economics Prior to approval in the US, parents of children with Dravet Syndrome were paying around $1,000 for a month supply to obtain it from Europe. References External links Secondary alcohols Anticonvulsants Orphan drugs Benzodioxoles Alkene derivatives GABAA receptor positive allosteric modulators Tert-butyl compounds