What is the mechanism of action of Lisinopril?

Lisinopril is an angiotensin-converting enzyme (ACE) inhibitor. Its mechanism of action is to block ACE, the enzyme that converts angiotensin I (an inactive peptide) to angiotensin II (a potent vasoconstrictor). By preventing angiotensin II formation, lisinopril causes vasodilation and reduces aldosterone secretion, thereby lowering blood pressure and reducing cardiac workload. A common side effect relevant to dentistry is a dry, persistent cough (due to bradykinin accumulation) and rarely angioedema. The original option stating 'inhibits conversion of angiotensinogen' was factually incorrect—ACE converts angiotensin I to angiotensin II, not angiotensinogen.