Calcium Channel Blockers Not Best for Hypertension

ByABC News

L O N D O N, Dec. 8, 2000 -- Calcium channel blockers, populardrugs used to lower high blood pressure, are not as effective asother treatments, researchers said today.

Two reviews of studies assessing blood pressure drugs,published in The Lancet medical journal, showed people treatedwith calcium channel blockers (CCBs) were more likely to suffera heart attack or other complications.

“In an analysis of more than 27,000 patients with high bloodpressure, we found that those treated with CCBs had a 26 percenthigher risk of heart attack and a 25 percent higher risk ofheart failure than those treated with other drugs,” saidProfessor Marco Pahor.

Better Than Nothing

CCBs were more effective than no treatment, but the risk ofall heart problems — heart attacks, stroke, heart failure anddeath from heart disease — was 10 percent higher in patientstreated with CCBs.

“These results show that CCBs are less effective than thestandard drugs used to treat high blood pressure,” Pahor, ofWake Forest University Baptist Medical Center in North Carolina,added.

CCBs, which are also known as calcium antagonists, work byinhibiting the passage of calcium, an important element formuscle contraction, into cells of the heart and muscle fibers ofblood vessels.

The researchers compared the effects of CCBs to diuretics orwater pills, and beta-blockers and ACE (angiotension convertingenzyme) inhibitors.

The review of nine studies showed CCBs were just as good asthe other treatment in lowering blood pressure but not aseffective in preventing complications such as heart attacks andheart failure.

Limited Use of CCBs

“These data reinforce the view that use of CCBs should belimited to patients who do not tolerate, or who have failed ondiuretics, beta blockers or ACE inhibitors,” said Dr WilliamApplegate, a co-author of the study.

The findings were supported by another overview byresearchers in Australia. It showed CCBs decreased the risk ofstroke but did not significantly reduce cases of heart disease,heart failure and deaths.

In a commentary in The Lancet, Jiang He and Paul Whelton ofTulane University in New Orleans said the overviews show CCBsshould be used selectively.

“The findings indicate the need for caution in recommendingcalcium antagonists as initial antihypertensive [low-bloodpressure] drug therapy in populations at risk of coronary heartdisease and heart failure,” they said.

“It might be wise to use calcium antagonists as initialantihypertensive drugs for patients at high risk of stroke andat low risk of coronary heart disease,” they added.

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