Quinapril is an ACE inhibitor. ACE stands for angiotensin converting enzyme. Quinapril is used to treat high blood pressure (hypertension) and heart failure. Quinapril may also be used for purposes not listed in this medication guide.Click to see full answer. Then, when should quinapril be taken?Your doctor is likely to advise you to take your very first dose at bedtime. This is because the first dose can make you feel dizzy. After the first dose, you can take quinapril at a time of day you find easy to remember, but try to take it at the same times of day each day.Also Know, does quinapril make you pee? Tell your doctor right away if you experience any of the symptoms listed in the Quinapril Warnings section above, or any of the following serious side effects: Severe dizziness. Lightheadedness or fainting. Decreased urination. Regarding this, is quinapril safe to take? Quinapril is used for long-term treatment. It comes with serious risks if you don’t take it as prescribed. If you don’t take it at all: Your blood pressure will stay high. If high blood pressure isn’t treated, it can lead to stroke, heart attack, heart failure, kidney failure, and vision problems.What class of drug is quinapril?Quinapril belongs in a class of drugs called angiotensin converting enzyme (ACE) inhibitors. ACE inhibitors are used for treating high blood pressure and heart failure and for preventing kidney failure due to high blood pressure and diabetes.