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Pharmacology 15

A 19-year-old man presents to a psychiatrist for a follow-up appointment for generalized anxiety disorder (GAD) and major depressive disorder (MDD). Medical history is otherwise unremarkable. His GAD and MDD were unresponsive to adequate trials of 2 different selective serotonin reuptake inhibitors (SSRIs), so the psychiatrist decided to start a serotonin-norepinephrine reuptake inhibitor (SNRI) at the previous visit. Today, he reports improvement in GAD and MDD symptoms, but he states he is having trouble achieving erections. He did not experience this side effect with either of the SSRIs. Review of systems is negative. Physical examination is normal.

Which of the following changes in intracellular ion concentration in smooth muscle is most likely leading to erectile dysfunction in this patient?

  • A) Decreased [Ca2+]
  • B) Decreased [Mg2+]
  • C) Decreased [Na+]
  • D) Increased [Ca2+]
  • E) Increased [Na+]


Tyler Natof


Dr. Ted O'Connell

Last updated

Jan 19, 2024

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