Nomifensine is an inhibitor of norepinephrine (NE) and dopamine (DA) reuptake. It inhibits uptake of NE, DA, and serotonin (5-HT) in rat brain synaptosomes with IC50 values of 6.6, 48, and 830 nM, respectively. It is selective for DA, NE, and 5-HT uptake inhibition over binding to dopamine D2, α1- adrenergic-, 5-HT2, and muscarinic receptors (IC50s = 43,000, 1,200, 3,800, and >13,000 nM, respectively, in rat brain membranes). Nomifensine is selective for inhibition of NE over DA uptake in vivo with minimal inhibitory doses of 28 and less than 57 μmol/kg, respectively. It decreases the time Wistar Kyoto, but not Sprague-Dawley, rats spend immobile in the forced swim test but also increases locomotor activity in the open field test in Wistar Kyoto and Sprague-Dawley rats when administered at a chronic dose of 10 mg/kg.