Pharmacology · single question
A patient taking an ACE inhibitor develops increased nasal congestion. Which mediator is primarily responsible for this side effect?
Show answer and explanation
Correct answer: A. Bradykinin
- A. CORRECT. ACE inhibitors block the breakdown of bradykinin. Accumulated bradykinin increases vascular permeability and causes nasal congestion/rhinitis and cough — the classic ACE inhibitor side effects. Bradykinin acts via B2 receptors on endothelial cells to induce vasodilation and plasma extravasation.
- B. Prostaglandin E2 contributes to inflammation but is not the primary mediator in ACE inhibitor-induced nasal congestion.
- C. Serotonin is not significantly involved in ACE inhibitor-related nasal symptoms.
- D. Histamine causes rhinitis in allergic reactions but is not the mechanism behind ACE inhibitor-induced nasal congestion.