Amitriptyline is classified as which type of antidepressant?

• A. SNRI
• B. SSRI
• C. TCA
• D. MAOI

Answer: (C)

Amitriptyline is a tricyclic antidepressant. Its primary action is to block the reuptake of norepinephrine and serotonin, increasing these neurotransmitters in the synaptic cleft. This broad mechanism is characteristic of TCAs, setting them apart from other antidepressant classes that are more selective.

Because TCAs also block other receptors (muscarinic, histaminic, and alpha-adrenergic), they tend to cause anticholinergic effects like dry mouth, blurred vision, urinary retention, and sedation, along with potential orthostatic hypotension. They also carry a higher risk of cardiotoxicity in overdose due to effects on cardiac conduction.

In contrast, SSRIs selectively inhibit serotonin reuptake, SNRIs affect both serotonin and norepinephrine but are not TCAs, and MAOIs work by inhibiting monoamine oxidase to increase monoamines.