Prescribing Safety Assessment (PSA) Practice Exam

How do ACE inhibitors lead to a dry cough?

1. By reducing blood pressure

2. By increasing bradykinin accumulation

3. By affecting sodium retention

4. By blocking angiotensin II

The correct answer is: By increasing bradykinin accumulation

ACE inhibitors lead to a dry cough primarily due to their effect on bradykinin levels in the body. When these medications inhibit the angiotensin-converting enzyme (ACE), they not only decrease the formation of angiotensin II but also prevent the breakdown of bradykinin. Elevated levels of bradykinin can cause irritation of the respiratory tract, leading to a persistent dry cough in some patients. Bradykinin is a peptide that promotes inflammation and vasodilation, which can result in increased bronchial hyperreactivity. This inflammatory response due to bradykinin accumulation is believed to be the mechanism behind the cough that is often associated with ACE inhibitor therapy. Understanding this relates to the clinical management of patients on ACE inhibitors, as it is a common side effect that may necessitate discontinuation or switching to alternative medications.