Lisinopril is used to treat high blood pressure. Lowering high blood pressure helps prevent strokes, heart attacks, and kidney problems. It is also used to treat heart failure and to improve survival after a heart attack. Lisinopril belongs to a class of drugs known as ACE inhibitors. It works by relaxing blood vessels so blood can flow more easily. If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.