Pitolisant hydrochloride,
a first-in-class inverse agonist of the histamine H3
receptor, was approved in the EU for the treatment of excessive
daytime sleepiness (EDS) in adults with narcolepsy with or
without cataplexy. The drug, which was developed by
Bioprojet and has orphan drug designation in the EU and
US, enhances wakefulness by increasing histaminergic neuron
activity. With once daily oral administration in the morning,
patients taking pitolisant exhibited significantly reduced EDS
versus placebo but not versus modafinil. Plasma levels of the
drug are reduced at the end of the day such that its waking
effect is minimized at night (plasma t1/2 10-12 h). Several
articles have been published detailing the discovery of
pitolisant.