We found that monoamine oxidase activity is acutely affected by pharmacologically different antidepressants; this effect is inhibitory. There are differences both in inhibitory potency and in mechanism of inhibition between both several drugs and the two monoamine oxidase isoforms.
While monoamine oxidase inhibition is not primary biochemical effect related to their therapeutic action, it can be supposed that decrease of monoamine oxidase activity may be concerned in some effects of these drugs on serotonergic, noradrenergic, and dopaminergic neurotransmission.