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Blueprint for Health: A Patient Teaching Aid

Understanding the Biology of ACE Inhibitors

by Jamie Reiter, Ph.D.

Summary

Angiotensin converting enzyme (ACE) inhibiting drugs are typically used to treat high blood pressure (hypertension). Physicians and researchers are also finding these drugs useful for congestive heart failure, complications associated with diabetes and after a heart attack. Three out of four patients using ACE inhibitors for their high blood pressure will have a reduction in their blood pressure. ACE inhibitors also improve the survival of patients with congestive heart failure or insulin-dependent diabetes associated with kidney failure.

Angiotensin converting enzyme (ACE) inhibiting drugs have been on the market since the 1970s for the treatment of high blood pres-sure. ACE inhibitors work by blocking the production of a chemical called angiotensin II. This chemical constricts arteries and subsequently causes blood pressure to rise. In recent years, researchers and physicians have found the ACE inhibitors are effective in treating several diseases, including congestive heart failure, excess protein in the urine (proteinuria) and certain kidney disorders that occur in some patients with insulin-dependent diabetes. In addition, these drugs have been shown to reduce the rates of heart attack, stroke, congestive heart failure, complications related to diabetes and sudden cardiac death.

High Blood Pressure

Approximately 75% of patients using ACE inhibitors have shown a modest reduction in blood pressure, for all age groups and both genders. ACE inhibitors are generally less effective in African-Americans, although changes in dosage or the addition of other drugs can increase their effectiveness.

Heart Attack and Congestive Heart Failure

In patients who have suffered a heart attack, ACE inhibitors have prevented development of congestive heart failure in approximately 30% and have reduced mortality.

In patients with congestive heart failure, ACE inhibitors reduced mortality and hospitalization by one-third or more.

Diabetes Mellitus

ACE inhibitors have been shown to protect against kidney damage and to prevent protein in the urine associated with diabetes. In one study, insulin-dependent diabetics with kidney failure resulting from diabetes who were treated with an ACE inhibitor showed protection against deterioration of kidney function.

Side Effects

One reason for the popularity of ACE inhibitors in treat-ing high blood pressure is the low risk of side effects. They don't cause fluid retention nor do they increase the risk of heart failure or heart attack as do some other drugs used to treat high blood pressure. The most common side effect of an ACE inhibitor is coughing, and approximately 10% of patients have stopped use of the drug because of that. Reducing the dosage has helped some patients continue on the medication. Rare side effects include rash, loss of taste, hypotension (low blood pres-sure) and swelling. Individuals experiencing one of these side effects should contact their physician or pharmacist, but they should not stop taking the medicine on their own.

Choosing an ACE Inhibitor

Several ACE inhibitors are on the market. Here is a list of some by generic name followed by brand name(s).

benazepril (Lotensin)
captopril (Capoten)
enalapril (Lexxel, Vaseretic, Vasotec)
fosinopril (Monopril)
lisinopril (Prinivil, Prinzide, Zestoretic, Zestril)
moexipril (Univasc)
quinapril (Accupril)
ramipril (Altace)
trandolapril (Mavik, Tarka)

A doctor considers several things when choosing a particular medicine: the number of doses needed per day, cost, whether the drug is available in an individual's health insurance plan and how the drug affects the individual's quality of life.

It is important to take your medicine as your doctor prescribed so it will work the best for you. If you have any questions about your medicine, please ask your doctor or pharmacist.

(Information for this article was compiled from data in articles on ACE inhibitors by Dominic Raco, M.D., [Clinical Review 1998; Winter 7-11], by Miguel Valderrábano, M.D., and Jeffrey S. Goodman, M.D., [Geriatric Times 2000; 1 (1) pp 13-19] and by Lynn Wilson [Medical Sciences Bulletin].).com