PITOLISANT OXALATE

Description: Pitolisant oxalate (formerly also known as BF2.649 oxalate, Tiprolisant oxalate, BF2649 oxalate and Ciproxidine oxalate) is a novel, potent and selective nonimidazole inverse agonist of the recombinant human histamine H3 receptor with Ki of 0.16 nM. Histamine H3 receptor inverse agonists are known to enhance the activity of histaminergic neurons in brain and thereby promote vigilance and cognition. On the stimulation of guanosine 5'-O-(3-35Sthio)triphosphate binding to this receptor, BF2.649 behaved as a competitive antagonist with a Ki value of 0.16 nM and as an inverse agonist with an EC50 value of 1.5 nM and an intrinsic activity approximately 50% higher than that of ciproxifan. Its in vitro potency was approximately 6 times lower at the rodent receptor. In mice, the oral bioavailability coefficient, i.e., the ratio of plasma areas under the curve after oral and i.v. administrations, respectively, was 84%. BF2.649 dose dependently enhanced tele-methylhistamine levels in mouse brain, an index of histaminergic neuron activity, with an ED50 value of 1.6 mg/kg p.o., a response that persisted after repeated administrations for 17 days. In rats, the drug enhanced dopamine and acetylcholine levels in microdialysates of the prefrontal cortex. In cats, it markedly enhanced wakefulness at the expense of sleep states and also enhanced fast cortical rhythms of the electroencephalogram, known to be associated with improved vigilance. On the two-trial object recognition test in mice, a promnesiant effect was shown regarding either scopolamine-induced or natural forgetting. These preclinical data suggest that BF2.649 is a valuable drug candidate to be developed in wakefulness or memory deficits and other cognitive disorders.

References: J Pharmacol Exp Ther. 2007 Jan; 320(1):365-75.

Related CAS#: 903576-44-3 (HCl); 362665-56-3 (free base)