Fosinopril sodium is primarily used in the treatment of high blood pressure (hypertension). It works by relaxing blood vessels, which helps to lower blood pressure and improve blood flow. This medication is also prescribed to manage heart failure, as it reduces the workload on the heart and enhances its efficiency. In some cases, it is used to improve survival rates after a heart attack. By inhibiting the angiotensin-converting enzyme (ACE), it prevents the production of a substance that narrows blood vessels, thereby aiding in maintaining cardiovascular health. Always taken under medical supervision, it is part of a comprehensive treatment plan that may include diet, exercise, and other medications.