Monoamine Oxidase Inhibitors - Mechanism - Indications - Side/adverse effects - Antidepressant Drugs:

Monoamine Oxidase is an enzyme responsible for the inactivation of monoamines i.e, nor epinephrine, dopamine and serotonin. By blocking this enzyme we increase the availability of these neurotransmitters in synapses.

But one should monitor the blood pressure and cardiac condition. As the increased quantity of nor epinephrine can cause hypertensive crises in predisposed individuals.

Following drugs come under this category

Ø     Selegiline

Ø     Phenelzine

Ø     Tranylcypromine

Indications:

MAO inhibitors are indicated for depressive patients who are unresponsive to TCAs or TCAs are contraindicated (eg. Allergy).

These agents are useful in the treatment of certain phobias. A condition called atypical depression can be treated by MAO inhibitors

Adverse effects:

Tyramine-containing foods must be avoided. Tyramine causes the release of stored catecholamines from nerve terminals, resulting in headache, stiff neck, tachycardia, nausea, hypertension, cardiac arrhythmias, seizures, and stroke. 

Other side effects include

    Drowsiness

    Nausea

    Orthostatic hypotension

    Blurred vision

    Dry mouth

    Dysuria

    constipation