SB 271046 Hydrochloride (SB 271046A) shows pKi values of 6.55, 6.35, 6.27, 6.05, 5.95, 5.76, 5.73, 5.62, 5.55, 5.41, 5.39, 5.27 and < 4.99 at 5-HT1D, 5-HT1A, D3, 5-HT1B, 5-HT1F, α1B, 5-HT2C, 5-HT2A, D2, 5-HT2B, 5-HT7, 5-HT4 and 5-HT1E respectively. SB-271046 Hydrochloride competitively antagonizes 5-HT-induced stimulation of adenylyl cyclase activity with a pA2 of 8.71.