Desipramine

Desipramine is a tricyclic antidepressant (TCA) that selectively blocks reuptake of norepinephrine (noradrenaline) from the neuronal synapse. It also inhibits serotonin reuptake, but to a lesser extent compared to tertiary amine TCAs such as imipramine. Inhibition of neurotransmitter reuptake increases stimulation of the post-synaptic neuron. Chronic use of desipramine also leads to down-regulation of beta-adrenergic receptors in the cerebral cortex and sensitization of serotonergic receptors. An overall increase in serotonergic transmission likely confers desipramine its antidepressant effects. Desipramine also possesses minor anticholinergic activity, through its affinity for muscarinic receptors. TCAs are believed to act by restoring normal levels of neurotransmitters via synaptic reuptake inhibition and by increasing serotonergic neurotransmission via serotonergic receptor sensitization in the central nervous system.