See the DrugPatentWatch profile for Captopril
How does captopril work in the body?
Captopril is an ACE inhibitor. It blocks angiotensin-converting enzyme (ACE), which normally converts angiotensin I into angiotensin II [1]. With less angiotensin II available, captopril lowers vasoconstriction and helps reduce blood pressure [1].
ACE also breaks down bradykinin. By inhibiting ACE, captopril can increase bradykinin levels, which contributes to vasodilation and the drug’s blood-pressure–lowering effect [1].
What changes in the renin–angiotensin–aldosterone system (RAAS)?
By inhibiting ACE, captopril reduces angiotensin II signaling. That leads to lower aldosterone release, which supports reduced sodium and water retention, further lowering blood pressure [1].
Does captopril have any direct effects outside ACE?
Its primary pharmacologic action is ACE inhibition. The downstream effects—reduced angiotensin II (less vasoconstriction and aldosterone) and increased bradykinin (more vasodilation)—are the key mechanisms responsible for its clinical effects [1].
What are the practical consequences of these mechanisms?
Because captopril decreases angiotensin II–mediated vasoconstriction and aldosterone-driven fluid retention, it lowers systemic blood pressure and can help in conditions where RAAS activation contributes to disease, such as hypertension and heart failure [1].
Source
[1] https://www.drugbank.com/drugs/captopril