Caution urged when prescribing for elderly

Medication requirements may change as a patient's metabolism slows and side effects persist longer.

By Susan J. Landers, AMNews staff. Sept. 13, 2004.

Washington -- A new study by Duke University researchers seems like déjà vu all over again in its finding that large numbers of elderly Americans are receiving prescriptions for medications that are believed to be potentially dangerous for them.

The study found that over the course of a year, one in five of the more than three-quarters of a million elderly patients studied filled a prescription for at least one drug determined to be inappropriate by a panel of geriatricians and others.

Two drugs, amitriptyline and doxepin, accounted for 23% of those prescriptions, said the researchers.

Some drugs impact elderly people differently, largely because of slower metabolism. "Drugs tend to stick around much longer in an older person's body than they do in a younger person's," said the study's lead author Lesley Curtis, PhD, assistant research professor at the Duke Center for Clinical and Genetic Economics.

Side effects such as dizziness and sleepiness may linger from evening into the next day for older people, thus increasing their risk for falls and other accidents. The potential problems are often exacerbated by multiple medications taken for several chronic conditions.

Dr. Curtis and colleagues used a large outpatient prescription claims database of a national pharmaceutical benefit manager to see which of the 765,423 subjects 65 or older had filled prescriptions for medications that met criteria first developed in 1991 by Mark H. Beers, MD, and associates for determining which drugs older people should avoid.