Topic overview

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MAOIs inhibit monoamine oxidase A and/or B, increasing synaptic norepinephrine, serotonin, and dopamine. Agents include phenelzine, tranylcypromine, isocarboxazid, selegiline, and the reversible inhibitor moclobemide. They may be used for atypical or treatment-resistant depression and anxiety disorders; selegiline also has an adjunct role in Parkinson disease. Most MAOIs act irreversibly, so their effects can persist until new enzyme is synthesized, and transitions to or from certain interacting medicines require a washout period. Important hazards include hypertensive crisis with tyramine-rich foods and serotonin syndrome with interacting drugs. Adverse effects, contraindications, overdose, and gradual discontinuation are also key safety topics.