SB224289 is a selective antagonist of 5-HT1B receptor with pKi of 8.2. It is a centrally active following oral administration in vivo. SB224289 displays 60-fold selectivity over 5-HT1D, 5-HT1A, 5-HT1E, 5-HT1F, 5-HT2A and 5-HT2C receptors in radioligand