Monoamine oxidase inhibitors — consultant viva

Station structure

Time: 8–10 minutes. Depth: consultant teaching registrar. Expect isoform logic, washout numbers, and clear separation of cheese reaction from serotonin toxicity without inventing universal dose tables that contradict product labels.[1][7]

Core questions and model points

1. Classify MAOIs. Irreversible nonselective (phenelzine, tranylcypromine, isocarboxazid); RIMA moclobemide; selegiline patch for MDD; oral MAO-B selective Parkinson niche. Antidepressant effect tracks mainly MAO-A inhibition.[1][8]

2. When do you use them? TRD specialist pathway; atypical depression historical preferential response (Liebowitz). Not casual first-line for mild MDD.[1][2]

3. Washouts. ~2 weeks most AD → irreversible MAOI; ~5 weeks after fluoxetine; ~2 weeks MAOI → SSRI/SNRI. No SSRI–MAOI combination.[1]

4. Cheese reaction mechanism and diet. Tyramine not destroyed by gut/liver MAO-A → pressor crisis. Teach high-tyramine aged/fermented/spoiled foods with modern refined lists.[7]

5. Forbidden drugs. SSRI/SNRI, clomipramine, pethidine, tramadol, dextromethorphan, St John's wort, linezolid contexts.[6][1]

6. Selegiline patch. Bodkin/Amsterdam efficacy; diet liberalisation mainly at 6 mg/24 h; reintroduce caution at 9–12 mg; serotonergic bans always.[4][5]

7. STAR*D late pathway. Tranylcypromine vs venlafaxine+mirtazapine — low remission; specialist intensity.[3]

8. RIMA advantage. Reversible MAO-A; meta-analytic efficacy; gentler diet — not zero rules.[8]

Pass criteria

• Correct washout arithmetic including fluoxetine exception.[1]
• Tyramine crisis ≠ serotonin toxicity, with correct co-triggers.[6][7]
• Selegiline patch dose–diet nuance stated accurately.[4][5]
• Named evidence threads (Liebowitz, STAR*D L4, STS RCTs) without overclaiming cure rates.[2][3][4]