Prometheus 6

The study, published in the Journal of the American Geriatrics Society, was conducted by Dr. Malaz Boustani, a geriatrician at the Indiana University School of Medicine. He said he noticed that a significant number of his hospitalized patients appeared confused when they were taking medications to reduce acid reflux.

To explore the link, he looked at 1,558 black Indianapolis residents who had taken part in other studies through the school. None had dementia when the study began.

Acid inhibitors may raise dementia risk
A study of elderly blacks indicates that those who are chronic users are more likely to develop the disease. The drugs inhibit a chemical involved in memory.
By Thomas H. Maugh II
Times Staff Writer
August 4, 2007

Elderly African Americans who are chronic users of acidinhibiting medications in the family that includes Zantac, Pepcid and Tagamet have 2 1/2 times the normal risk of developing dementia, Indiana researchers reported Friday.

The drugs block production of stomach acid by inhibiting so-called histamine-2 receptors; a pump in the stomach releases hydrochloric acid when stimulated by histamines.

But they also inhibit the brain's cholinergic system, which is involved in memory and cognition. Low levels of cholinergic activity have previously been linked to dementia.

There have been hints that the drugs, known as histamine-2 receptor antagonists, might be linked to dementia, but previous studies have come down on both sides of the question, said Dr. John Morris of Washington University in St. Louis, who was not involved in the study.

"This is certainly not the final word on the potential risk of these drugs," he said. "But what it tells us is that, for older adults, drug use should be considered very carefully."

Dr. Constantine G. Lyketsos, a psychiatrist at Johns Hopkins University, who was also not involved in the study, said: "This is one of the medicines we worry about when people with Alzheimer's are taking them. It can make memory worse and lead to confusion. Whether they will make it more likely that someone will develop Alzheimer's or dementia is still an open question."

GlaxoSmithKline, which manufactures Tagamet and Zantac, did not return calls seeking comment.

The study did not look at other races, and there was not enough data to suggest a risk from a different family of acidinhibiting drugs called proton pump inhibitors, which includes Prilosec, Nexium and Prevacid.