1-Piperidinecarboxylic acid, 3-[[2-[2,6-difluoro-4-[(methylamino)carbonyl]phenyl]-7-methylimidazo[1,2-a]pyridin-3-yl]methyl]-, methyl ester, (3S)-

P2X3 antagonist 34 (BLU-5937; 500 nM) is able to block αβ-meATP-induced sensitization and firing activity of isolated primary nociceptors in rat dorsal root ganglions (DRGs), through P2X3 homotrimeric receptor antagonism. The sensitizing effect of αβ-meATP and the inhibition of P2X3 antagonist 34 are reversible after washout.

P2X3 antagonist 34 (BLU-5937; 0.3-0 mg/kg, oral administration; male Dunkin Hartley guinea pigs) treatment significantly reduces the histamine-induced enhancement in the number of citric acid-induced coughs in a dose -dependent fashion in a guinea pig cough model.
It (BLU-5937; 3 and 30 mg/kg, oral) is also shown to reduce significantly and dose-dependently the ATP-induced enhancement of citric acid- induced coughs in the guinea pig.

IC50: 25 nM (Human P2X3 receptor), 92 nM (Rat P2X3 receptor) and 126 nM (Guinea pig P2X3 receptor), 1820 nM (Rat P2X2/3 heterotrimeric receptor) and 3450 nM (Guinea pig P2X2 /3 heterotrimeric receptor)