Used in the treatment of hypertension and heart failure, fosinoprilat works by inhibiting the angiotensin-converting enzyme (ACE), which reduces the production of angiotensin II—a substance that narrows blood vessels and increases blood pressure. By blocking this enzyme, it helps blood vessels relax and widen, improving blood flow and lowering blood pressure. This action also reduces the workload on the heart, making it beneficial for patients with left ventricular dysfunction following myocardial infarction. It is the active metabolite of the prodrug fosinopril, formed in the body after oral administration.