Dual 5-HT1B/1D receptor antagonist (pKB values are 9.05 and 8.98 respectively) and 5-HT re-uptake inhibitor (pIC50 = 8.48). Potently antagonizes terminal autoreceptor activity in vitro and increases extracellular 5-HT levels above those evoked by fluoxetine (Cat. No. 0927) in vivo. Also acts as an antagonist at 5-HT2A and 5-HT2B receptors (pKi values are 7.29 and 7.35 respectively).