Blocking dopamine receptors by an antipsychotic typically leads to which change in prolactin secretion?

• A. Decrease
• B. Increase
• C. No Change
• D. Variable With Dose

Answer: (B)

Dopamine tonically inhibits prolactin release through D2 receptors on lactotrophs in the tuberoinfundibular pathway. When an antipsychotic blocks these receptors, this inhibitory control is removed, leading to increased prolactin secretion (hyperprolactinemia). This rise is often dose-related and is more pronounced with agents that strongly antagonize D2 in the pituitary, such as risperidone. Clinically, hyperprolactinemia can cause galactorrhea, amenorrhea or infertility in women, and gynecomastia or sexual dysfunction in men. Decrease or no change don’t fit because blocking dopamine lifts inhibition and increases prolactin; while saying it’s variable with dose is less precise than stating the common outcome is an increase, though the magnitude can vary by drug and dose.