Maprotiline

Maprotiline exerts its antidepressant action by inhibition of presynaptic uptake of catecholamines, thereby increasing their concentration at the synaptic clefts of the brain. In single doses, the effect of maprotiline on the EEG revealed a rise in the alpha-wave density, a reduction of the alpha-wave frequency and an increase in the alpha-wave amplitude. However, as with other tricyclic antidepressants, maprotiline lowers the convulsive threshold. Maprotiline acts as an antagonist at central presynaptic α2-adrenergic inhibitory autoreceptors and hetero-receptors, an action that is postulated to result in an increase in central noradrenergic and serotonergic activity. Maprotiline is also a moderate peripheral α1 adrenergic antagonist, which may explain the occasional orthostatic hypotension reported in association with its use. Maprotiline also inhibits the amine transporter, delaying the reuptake of noradrenaline and norepinephrine. Lastly, maprotiline is a strong inhibitor of the histamine H1 receptor, which explains its sedative actions.