Ellington

A new study shows that a common medication for overactive bladder may cause subtle memory problems in adults.

Gary G. Kay, an associate professor of neurology at Georgetown University, became interested in a medication called Ditropan XL, on the market for almost a decade. An earlier version offered in three daily doses was introduced in the 1960s. In the last few years, the Food and Drug Administration has approved four other drugs for overactive bladder, which affects 16 percent of the population, mostly older people. This class of medications works on cholinergic cells in the bladder.

But the brain also contains a robust supply of cholinergic neurons, which are the main target in dementia since in the brain they are involved in memory and learning. There had been reports of cognitive changes in animals using these bladder medications, and some rare complaints of significant but reversible cognitive problems among patients.

Kay and colleagues randomly assigned 150 volunteers (with no bladder problems or memory problems) to receive either of the two drugs -- Ortho-McNeil Pharmaceutical 's Ditropan XL or Novartis Pharmaceuticals Corp.'s Enablex -- or a placebo daily. The dose was increased weekly over the three-week study.

Volunteers were shown 14 named faces and asked to attach the name to the face 30 minutes later. These tests were given before they began taking the drug and then weekly.

Kay found that those taking Ditropan XL scored significantly worse on the memory tests compared with those taking Enablex or placebo. There was no change among those taking Enablex or placebo.

Kay said the scores represented a 10-year drop in memory function. "Sixty-seven-year-olds were performing like 77-year-olds," Kay said. His findings were presented this week at the American Urological Association's annual meeting in Atlanta.

Unlike dementia, these memory problems didn't progress, and clinical opinion is that the problem disappears once the drug is stopped.

Kay and his colleagues did not study patients with known memory or cognitive problems.

Based on this study, Dr. Joseph G.Ouslander said he would be concerned giving such medicines to patients with mild cognitive impairment or Alzheimer's.

Kay said he approached Novartis to fund the study, which is now in press in the journal, European Urology. Novartis had nothing to do with the testing or the analysis of the data, Kay said. "Whatever way it turned out, we were going to report the results," Kay said.

"A large number of studies have been conducted to assess various aspects of cognitive impairment associated with the use of anticholinergic agents in elderly patients," said Julie Keenan, communications director of Ortho-McNeil woman's health and urology division. "It is difficult to draw conclusions about the impact of an anti-cholinergic agent on cognitive function based on the findings on a single study."