Potent σ receptor agonist (Ki values are 59.1 and 2 nM for σ1 and σ2 receptors respectively) and NR2B subunit-selective NMDA receptor antagonist (IC50 values are 0.22 and 324.8 μM at NR2B and NR2A respectively). Displays ~8-fold reduced affinity at α-adrenoceptors compared to Ifenprodil (Cat.No. 0545). Inhibits the hERG potassium channel (IC50 = 88 nM) and exhibits antiarrhythmic activity in vivo.