The given answer, prinivil and zestril, are both brand names for the generic drug lisinopril. Lisinopril is commonly used to treat high blood pressure and heart failure. It belongs to a class of medications called ACE inhibitors, which work by relaxing blood vessels, reducing fluid buildup, and improving blood flow. Prinivil and zestril are interchangeable and contain the same active ingredient, lisinopril, but are marketed under different brand names by different pharmaceutical companies.