Drug-induced hyperprolactinemia is commonly caused by which medications?

Drug-induced hyperprolactinemia is commonly caused by which medications?

• A. Antipsychotics
• B. Antidepressants
• C. Anti-nausea medications
• D. All of the above

Answer: (D)

Prolactin release from the pituitary is normally kept in check by dopamine acting on D2 receptors in the tuberoinfundibular pathway. When this dopaminergic brake is removed or reduced, prolactin levels rise. Antipsychotics are well known to cause this because many of them are D2 receptor antagonists in the brain and pituitary. Blocking these receptors lifts the inhibition on prolactin, so galactorrhea, menstrual disturbances, and even fertility issues can occur with these drugs. Anti-nausea medications like metoclopramide and prochlorperazine also block D2 receptors, including in the central nervous system, which similarly increases prolactin. This makes sense clinically when these agents are used for GI symptoms but can lead to signs of hyperprolactinemia. Antidepressants can contribute as well, particularly selective serotonin reuptake inhibitors. The rise in serotonin can dampen dopaminergic activity, indirectly removing inhibition on prolactin release. Some other antidepressants can have similar effects, though this is less common than with antipsychotics. Taken together, these mechanisms explain why all three categories can be implicated in drug-induced hyperprolactinemia. If a patient develops relevant symptoms on these medications, checking prolactin and considering a dose adjustment or alternative therapy is reasonable.

Prolactin release from the pituitary is normally kept in check by dopamine acting on D2 receptors in the tuberoinfundibular pathway. When this dopaminergic brake is removed or reduced, prolactin levels rise.

Antipsychotics are well known to cause this because many of them are D2 receptor antagonists in the brain and pituitary. Blocking these receptors lifts the inhibition on prolactin, so galactorrhea, menstrual disturbances, and even fertility issues can occur with these drugs.

Anti-nausea medications like metoclopramide and prochlorperazine also block D2 receptors, including in the central nervous system, which similarly increases prolactin. This makes sense clinically when these agents are used for GI symptoms but can lead to signs of hyperprolactinemia.

Antidepressants can contribute as well, particularly selective serotonin reuptake inhibitors. The rise in serotonin can dampen dopaminergic activity, indirectly removing inhibition on prolactin release. Some other antidepressants can have similar effects, though this is less common than with antipsychotics.

Taken together, these mechanisms explain why all three categories can be implicated in drug-induced hyperprolactinemia. If a patient develops relevant symptoms on these medications, checking prolactin and considering a dose adjustment or alternative therapy is reasonable.