Which drug is an SNRI?

Which drug is an SNRI?

• A. Desvenlafaxine
• B. Amitriptyline
• C. Phenelzine
• D. Lithium

Answer: (A)

An SNRI works by blocking the reuptake of both serotonin and norepinephrine, so brain levels of these two neurotransmitters rise. Desvenlafaxine does exactly that, fitting squarely into the SNRI class (it's the active metabolite of venlafaxine). The other drugs don’t share this mechanism: amitriptyline is a tricyclic antidepressant with broader receptor effects and many anticholinergic side effects, not classified as an SNRI; phenelzine is a monoamine oxidase inhibitor, which increases monoamines by preventing their breakdown rather than blocking reuptake; and lithium is a mood stabilizer with a different mechanism altogether.

An SNRI works by blocking the reuptake of both serotonin and norepinephrine, so brain levels of these two neurotransmitters rise. Desvenlafaxine does exactly that, fitting squarely into the SNRI class (it's the active metabolite of venlafaxine). The other drugs don’t share this mechanism: amitriptyline is a tricyclic antidepressant with broader receptor effects and many anticholinergic side effects, not classified as an SNRI; phenelzine is a monoamine oxidase inhibitor, which increases monoamines by preventing their breakdown rather than blocking reuptake; and lithium is a mood stabilizer with a different mechanism altogether.