Lisinopril is a medication belonging to the drug class of angiotensin-converting enzyme (ACE) inhibitors and is used to treat hypertension (high blood pressure), heart failure, and heart attacks. [7] Lisinopril is an oral medication used to treat high blood pressure and heart failure. Learn about side effects, warnings, dosage, and more. Find patient medical information for Lisinopril (Prinivil, Zestril, and Others) on WebMD including its uses, side effects and safety, interactions, pictures, warnings, and user ratings Learn about common and rare lisinopril side effects and what to do if they occur. Lisinopril is an ACE inhibitor. It is used to treat high blood pressure, congestive heart failure in adults, or to improve survival after a heart attack. Lisinopril is a type of medicine called an ACE inhibitor which makes your blood vessels relax and widen. This helps to lower your blood pressure and makes it easier for your heart to pump blood around your body. LISINOPRIL (lyse IN oh pril) treats high blood pressure and heart failure. It may also be used to prevent further damage after a heart attack. It works by relaxing blood vessels, which decreases the amount of work the heart has to do. It belongs to a group of medications called ACE inhibitors. Advertisement. Lisinopril is used alone or together with other medicines to treat high blood pressure (hypertension). High blood pressure adds to the workload of the heart and arteries. It is used in combination with other medications to treat heart failure. Lisinopril is also used to improve survival after a heart attack. Lisinopril is in a class of medications called angiotensin-converting enzyme (ACE) inhibitors. Learn about the side effects of lisinopril, from common to rare, for consumers and healthcare professionals.