Additional Effect of Vilazodone Compared to sertraline: Partial Agonist of the 5 Ht1a Receptor 1

Question

Vignette: A 45-year-old woman with a history of depression presents to her primary care physician for a routine check-up. She reports that she has been feeling well and that her mood has been stable for the past several months. Her current medications include sertraline and a multivitamin. She mentions that she read about a new drug for depression that has been shown to be highly effective and asks whether she should switch to it. She has brought a printout about the drug, which is called vilazodone. The physician reviews the printout and notes that vilazodone is a selective serotonin reuptake inhibitor (SSRI) and a partial agonist of the 5-HT1A receptor.

Question: Which of the following best describes the additional effect of vilazodone compared to sertraline?

Choices

A) Increased norepinephrine reuptake inhibition

B) Increased dopamine reuptake inhibition

C) Increased 5-HT1A receptor agonism

D) Decreased monoamine oxidase inhibition

E) Decreased serotonin-norepinephrine reuptake inhibition

Answer

C) Increased 5-HT1A receptor agonism

Explanation

Both sertraline and vilazodone are selective serotonin reuptake inhibitors (SSRIs) that work by blocking the reuptake of serotonin into presynaptic cells, which increases the amount of serotonin available to bind to the postsynaptic receptor. They are used to treat depression and a range of anxiety disorders. Vilazodone, however, is unique in that it also acts as a partial agonist of the 5-HT1A receptor. This receptor is a subtype of the serotonin receptor, and its activation leads to increased release of serotonin in the brain. Thus, vilazodone has a dual mechanism of increasing serotonin levels in the brain: by inhibiting its reuptake and by directly stimulating its release through 5-HT1A receptor agonism. This additional mechanism may contribute to its effectiveness in treating depression.