Captopril is part of a class of drugs called ACE inhibitors. ACE stands for angiotensin-converting enzyme. Captopril helps to block the angiotensin-converting enzyme, which is normally part of a reaction in the body that causes the blood vessels to narrow (constrict). By blocking this enzyme, the medication causes blood vessels to relax, which can lower blood pressure.
By helping blood vessels relax, the medicine also increases the efficiency of the heart. This means that the heart does not have to work as hard and more blood can be pumped out to the rest of the body. Both of these are helpful for a person with congestive heart failure.
A blood pressure reading consists of two numbers -- for example, 120/80. The top number is known as the systolic blood pressure, and the bottom number is the diastolic blood pressure. During clinical studies in people taking captopril, both systolic and diastolic blood pressures were significantly lowered. The higher the dose, the greater the drop in blood pressure tended to be. By lowering blood pressure, captopril can also decrease the risks that accompany long-term high blood pressure (see Effects of High Blood Pressure).
For people with congestive heart failure, the effects of captopril on the heart and blood vessels cause a decrease in the symptoms of congestive heart failure, including shortness of breath, fatigue, and swelling, along with improved exercise tolerance.
The medication can also decrease the damage to the kidneys in people with diabetic nephropathy. The exact way that this occurs, however, is not completely understood.
Some general considerations for when and how to take this drug include:
- Captopril comes in tablet form and is usually taken two or three times a day.
- It should be taken on an empty stomach at least one hour before a meal or two hours after a meal.
- The medication should be taken at the same time each day to maintain an even level of medicine in your blood.
- For the drug to work properly, you have to take it as prescribed. It will not work if you stop taking it.