Lisinopril high blood pressure drug, molecular model. This drug, marketed as Prinivil, Zestril and Lisodur, is used to treat hypertension (high blood pressure) and heart disease. It is an ACE inhibitor, a drug that works by blocking the action of angiotensin converting enzyme (ACE). This enzyme, as its name implies, converts the peptide angiotensin from its inactive to active form. The active form is a powerful vasoconstrictor (narrowing blood vessels), and vasoconstriction raises the blood pressure, so blocking ACE is a good way to reduce blood pressure. Atoms are shown as spheres and are colour coded: carbon is light blue, oxygen is orange, nitrogen is purple and hydrogen is white.