Galen Pharmacology Exam 1 Practice Test

A key distinction among atypical antipsychotics is how they affect dopamine. Aripiprazole is unique because it is a partial agonist at D2 receptors, acting as a dopamine system stabilizer. This means it can boost dopamine signaling when it’s too low and dampen it when it’s too high, helping control symptoms while reducing the risk of movement disorders and prolactin elevation that come with full D2 antagonists. It also has 5-HT2A antagonism and 5-HT1A partial agonism, contributing to its overall profile.

The other drugs listed are effective atypicals too, but they primarily block D2 receptors (antagonists) with 5-HT2A antagonism, which can lead to higher risks of EPS and hyperprolactinemia in some patients and have different metabolic effects. So, the atypical antipsychotic to know for its distinct mechanism is aripiprazole.