SBA — Single Best Answer · Review
Question 450
Pharmacology → General
Classification
Question
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A patient requires an antidepressant acting through monoamine oxidase inhibition, but minimisation of dietary tyramine interaction is particularly important. Which pharmacological profile best characterises reversible MAO-A inhibitors?
Question Stem
Select the single best answer.
Options
A
Marked potentiation of dietary tyramine requiring strict dietary restriction
B
Minor potentiation of the pressor response to ingested amines with no dietary restriction required
C
Predominant noradrenaline reuptake blockade with pronounced antimuscarinic effects
D
Irreversible dopamine receptor blockade with extrapyramidal adverse effects
E
Selective serotonin reuptake inhibition with obligatory tyramine avoidance
Explanation
Reversible inhibitors of MAO-A, including moclobemide and clorgyline, produce only minor potentiation of the pressor response to ingested amines; consequently dietary restrictions are not required. They also lack several adverse effects associated with typical tricyclic antidepressants.
Option Validity
A) Marked tyramine potentiation is characteristic of the conventional MAO inhibitors seen with conventional MAO inhibitors rather than reversible MAO-A inhibitors.
C) Noradrenaline reuptake blockade is a tricyclic antidepressant mechanism and is not the defining mechanism of RIMAs.
D) Dopamine receptor blockade is the principal mechanism of antipsychotic drugs.
E) Selective serotonin reuptake inhibition characterises SSRIs and is not the mechanism defining RIMAs.
Further Reading
Saxena R. Textbook for MRCOG-1. Chapter 12: Pharmacology. Antidepressant Drugs, p.346.