Monoamine Oxidase Inhibitors (MAOI) – Mechanism of Action | Psychopharmacology | Clinical Application

Posted on:April 7, 2021
Last Updated: April 29, 2024
Time to read: 13–15 minutes

Monoamine oxidase inhibitors (MAOIs) were the first antidepressant drugs along with imipramine to be developed for treating depression. Following WW2, large amounts of rocket fuel hydrazine were given to the pharmaceutical industry. In 1952 isoniazid derived from hydrazine was found to have anti-tubercular properties. Isoniazid was serendipitously found to have mood-elevating properties, and subsequently, numerous hydrazine and non-hydrazine structures were synthesized.

However, toxicity issues coupled with its complex and numerous interactions with other drugs and dietary amines have triggered a decline in clinical use as well as causing the discontinuation of many other MAOI derivatives. [Yáñez et al. 2012]

Due to their side effect profile, MAOIs are not considered as first or second-line therapies for depression, although they still have a place in treatment-resistant depression and other disorders such as panic disorder, social phobia, and depression with atypical features. [Thase 2012]