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| |  Study Links Between Calcium Blockers And Brain Damage, Memory Loss WINSTON-SALEM, NC -- December 2, 1997 -- Calcium channel blockers and certain kinds of diuretics are associated with brain damage and memory loss, according to a report in today's Journal of the American Geriatrics Society. The report comes from an analysis of participants with high blood pressure in the Cardiovascular Health Study (CHS), the largest study ever of the natural progression of heart disease and stroke in the elderly. The study, sponsored by the National Heart Lung and Blood Institute and begun in 1989, involves 5,888 residents of Forsyth County, N.C., Sacramento County, CA., Washington County, MD. and Pittsburgh, PA. Curt D. Furberg, M.D., Ph.D., professor and chairman of the department of public health sciences at the Wake Forest University School of Medicine, called the results a surprise finding. He said there was no reason to suspect that drugs that reduce high blood pressure would have such an adverse effect on the brain. The new research looked at the 1,268 CHS participants who were being treated for high blood pressure by their personal physicians, but who had never had a stroke or reported a transient ischemic attack (a ministroke). Furberg, national chairman of CHS Steering Committee, said they found more evidence of brain damage and lower scores on a standard mental test in participants taking calcium channel blockers or so-called loop diuretics than in those using beta blockers, so-called ACE (angiotensin-converting enzyme) inhibitors or thiazide diuretics. The brain damage turned up under a Magnetic Resonance Imaging (MRI) examination as what doctors call white matter hyperintensity, which has been associated with impaired memory. The standard mental test confirmed these findings of impaired memory. Furberg said the results are part of a pattern of problems with calcium channel blockers that began to emerge with a report at an American Heart Association meeting in March 1995 by Bruce Psaty, M.D., Ph.D., of the University of Washington and Furberg. "Now we have one article a month suggesting potential harm in the long-term use of calcium channel blockers," he said. The problems seem to arise in both long-acting and short-acting versions of the widely prescribed drugs, intended to treat high blood pressure and chest pain. He said the adverse results show up in both clinical trials -- experimental tests of drugs -- and in observational studies, where investigators follow participants over a number of years, but do not interfere with treatment or otherwise intervene. CHS is an observational study. Furberg said the accumulating evidence of a safety problem has convinced even those initially critical of his results. Around the world, fewer and fewer patients are taking calcium channel blockers. Furberg said the debate is also having a major impact on what drug companies are now doing to document the safety of drugs that they wish to market. The latest developments may also contain the explanation for why only some patients have problems with calcium channel blockers -- the problems are occurring primarily in diabetics. One study of diabetics with hypertension compared patients placed on ACE inhibitors with those placed on calcium channel blockers and found patients on the ACE inhibitor had half as many cardiovascular events as patients on calcium channel blockers. Furberg said six additional studies, some published, some about to be published, are reporting similar findings, showing calcium channel blockers are particularly unsafe for diabetics. Does that mean the drugs are safe for people without diabetes? "These drugs are untested in long-term trials and therefore, one can not conclude they are safe," Furberg said.
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