Cyclopropyl[4-[3-(1H-imidazol-5-yl)propoxy]phenyl]methanone hydrochloride

Ciproxifan belongs to a novel chemical series of histamine H3-receptor antagonists. In vitro, it behaved as a competitive antagonist at the H3 autoreceptor controlling 3H histamine release from synaptosomes and displayed similar Ki values (0.5-1.9 nM) at the H3 receptor controlling the electrically-induced contraction of guinea pig ileum or at the brain H3 receptor labeled with 125I-iodoproxyfan. This appears to be an orally bioavailable, extremely selective and potent H3-receptor antagonist whose vigilance- and attention-promoting effects are promising for therapeutic applications in aging disorders.