Maprotiline is a norepinephrine reuptake inhibitor that binds the norepinephrine transporter with a KD value of 11.1 nM. Comparatively, it only weakly associates with serotonin and dopamine transporters (KDs = 5.8 and 1 μM, respectively). However, maprotiline moderately inhibits serotonin 5-HT2A receptors with a Ki value of 51 nM. Maprotiline has also been reported to bind the histamine H1, muscarinic acetylcholine, α1-adrenergic, and dopamine D2 receptors with KD values of 2, 570, 90, and 350 nM, respectively. It has been used in the treatment of depression and also has been reported to possess sedative, anxiolytic, and sympathomimetic activities.