Sibutramine is which of the following in terms of status and mechanism?

Sibutramine is which of the following in terms of status and mechanism?

• A. Discontinued; Norepinephrine, Serotonin, and Dopamine Reuptake Inhibitor
• B. Discontinued; GABA receptor agonist
• C. Active; Norepinephrine reuptake inhibitor only
• D. Active; Serotonin receptor antagonist

Answer: (A)

Sibutramine’s status and mechanism hinge on two facts: its medical history and how it works. It used to be prescribed for obesity, but it has been withdrawn from the market due to safety concerns, specifically an increased risk of heart attack and stroke. Mechanistically, it blocks the reuptake of three monoamines—norepinephrine, serotonin, and dopamine—so it acts as a three-way monoamine reuptake inhibitor. This is what drives its appetite-suppressing effects, but also contributes to cardiovascular risk. This isn’t a GABA receptor agonist, which would affect the inhibitory GABA system and produce very different effects. It’s also not simply an active drug that inhibits only norepinephrine reuptake; it’s the combined inhibition of norepinephrine, serotonin, and dopamine that characterizes sibutramine’s mechanism and its withdrawal from use.

Sibutramine’s status and mechanism hinge on two facts: its medical history and how it works. It used to be prescribed for obesity, but it has been withdrawn from the market due to safety concerns, specifically an increased risk of heart attack and stroke. Mechanistically, it blocks the reuptake of three monoamines—norepinephrine, serotonin, and dopamine—so it acts as a three-way monoamine reuptake inhibitor. This is what drives its appetite-suppressing effects, but also contributes to cardiovascular risk.

This isn’t a GABA receptor agonist, which would affect the inhibitory GABA system and produce very different effects. It’s also not simply an active drug that inhibits only norepinephrine reuptake; it’s the combined inhibition of norepinephrine, serotonin, and dopamine that characterizes sibutramine’s mechanism and its withdrawal from use.