Whites, blacks respond similarly to common blood pressure drugs

Whites and blacks respond similarly to all common blood pressure drugs, according to a new study in the March 2004 issue of Hypertension, a journal of the American Heart Association. While several previous studies have tended to emphasize the differences in response to blood pressure medication by race, this new investigation systematically examined all clinical trials from the last 20 years and found that whites and blacks are more alike than different when it comes to treating high blood pressure.

The investigation examined changes in blood pressure after administration of common antihypertensive drugs to 9,307 white subjects and 2,902 black subjects. For each drug, whites and blacks responded similarly about 90 percent of the time. These findings raise doubts about the value of using different drugs to treat whites and blacks.

According to the study's author, Ashwini Sehgal, M.D., of the Case Western Reserve University School of Medicine, physicians are taught that whites respond better to certain blood pressure drugs, such as beta blockers, while blacks respond better to other drugs, such as diuretics. This study sought to determine how much difference actually exists. Sehgal found that there is a small average difference between whites and blacks. However, this small difference is dwarfed by the variation within each race.

For example, there was a 1.5 point average difference between whites and blacks in response to diuretics, but the variation within each race was 6.2 points. The large variation means that some patients will respond well while others won't. However, race plays a minimal role in the extent of response.

"Certain drugs are especially beneficial for patients with heart or kidney disease," said Sehgal. "Picking drugs based solely on race means we will deny these benefits to some patients. Instead, physicians should pick a drug based on multiple factors including how well a drug lowers blood pressure in an individual patient, whether cardiac or renal benefits are needed, side effects, and cost."

Both genetic and environmental factors influence response to drugs. This investigation shows that race is not a good proxy for these genetic and environmental factors. More broadly, this study indicates that we should think twice before basing other types of medical treatment on race.

Sehgal is an associate professor of medicine, biomedical ethics, and epidemiology and biostatistics at Case and a member of the Division of Nephrology and Center for Health Care Research and Policy at MetroHealth Medical Center in Cleveland.

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