An NPSR antagonist (IC50s = 22 and 23.8 nM for the NPSR Asn107 and NPSR Ile107 isoforms, respectively); selective for NPSR over a panel of 14 G protein-coupled receptors exhibiting no activity at a concentration of 10 μM; reduces NPS-induced horizontal activity and vertical rearing and climbing in mice when administered at a dose of 50 mg/kg; reduces conditioned reinstatement of cocaine seeking in rats