Captopril was patented in 1976 and approved for medical use in 1980. It is an angiotensin-converting enzyme (ACE) inhibitor used for the treatment of hypertension, congestive heart failure, kidney problems caused by diabetes, and to improve survival after a heart attack. It is worth noting that ACE inhibitors, such as Captopril, work by blocking the action of a compound in the body called angiotensin converting enzyme (ACE). Normally ACE produces another compound called angiotensin II, as part of the body's natural control of blood pressure. Angiotensin II causes blood vessels to constrict and narrow, which increases the blood pressure. Therefore, by blocking the action of ACE, captopril reduces the production of angiotensin II, which allows the blood vessels to relax and widen. Bear in mind that you should not use this medication if you are pregnant, considering it can cause injury or death to the unborn baby. In addition, Captopril can pass into breast milk and may harm a nursing baby. So, you should not breastfeed while you are using it. You need to also remember that Captopril is usually taken two or three times a day on an empty stomach, 1 hour before a meal.