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Many Drugs Prescribed for Elderly Americans Are Risky

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Duke Health News 919-660-1306

DURHAM, N.C. -- Many Americans over the age of 65 hold
prescriptions for drugs considered potentially risky for
elderly patients, according to a new study by Duke University
Medical Center researchers. The finding emphasizes a need for
greater awareness among physicians about the risks presented by
commonly prescribed medications as people age and for
additional measures to monitor prescription drug use, the team
said.

The Duke researchers found that over the course of a year
one in five elderly Americans whose benefits were processed by
one of the largest pharmaceutical benefits managers in the U.S.
filled a prescription for at least one drug classified as a
"drug of concern," according to established criteria known as
the Beers list. Of those claims, half were for drugs --
including the anti-depressant amitriptyline (Elavil®, Endep®,
Vanatrip®) and anti-anxiety drug diazepam (Valium®) -- with
potential for severe adverse effects in older people, the
researchers reported in the Aug. 9, 2004, issue of Archives of Internal
Medicine
.

"Although criteria for drugs to avoid in the elderly have
been around for a long time, the amount of potentially
inappropriate prescribing for older patients remains really
high," said Lesley Curtis, Ph.D., a member of the Duke Center for Clinical
and Genetic Economicsand lead author of the study. The
center is part of the Duke Clinical Research
Institute
. The work was supported by a Centers for
Education and Research on Therapeutics cooperative agreement
between the Agency for Healthcare Research and Quality in
Rockville, Md., and the University of Arizona Health Sciences
Center in Tucson.

People over the age of 65 make up less than 15 percent of
the U.S. population, yet they account for nearly one-third of
drug consumption, noted Kevin Schulman, M.D., director of the
Duke Center for Clinical and Genetic Economics and senior
author of the study. Elderly individuals more often have
multiple chronic conditions, increasing the likelihood that
they take several drugs concurrently, he added. Furthermore,
many drugs present increasing risk for people as they age due
to changes in metabolism and excretion, whose effects are
complicated by the number of prescription drugs taken.

The list of criteria for determining the appropriate use of
medication in elderly living in nursing homes was developed in
1991 by a team led by Mark Beers at the University of
California, Los Angeles, culled from the opinions of a panel of
experts. In 1997, Beers updated the original list, initially
intended primarily for institutional use, for use in any
setting. The list named 28 medications or classes of
medications considered inappropriate for use in elderly
patients. The panel deemed 14 of those 28 medications to have
potentially severe adverse outcomes when taken by older
people.

In the current study, the Duke team analyzed the
prescriptions filled for all patients over 65 who filed claims
in 1999 through the outpatient prescription claims database of
AdvancePCS (now part of Caremark Rx, Inc.). The study
population included representatives of all 50 states, the
District of Columbia, Puerto Rico and two U.S. territories.

Of the 765,423 people included in the study, more than 20
percent (162,370) filled a prescription for one or more drugs
of concern during the year, they reported. While most patients
who made such a claim filled a prescription for a single Beers
list drug, nearly 16 percent (25,550) made claims for two risky
drugs and 4 percent (6,402) filled prescriptions for three or
more Beers list drugs within the same year.

In the study, 41 percent of elderly beneficiaries who filled
a prescription for a drug on the Beers list did so for a
psychotropic drug. Claims for the anti-depressants
amitriptyline and doxepin (Adapin®, Sinequan®, Zonalon®) alone
accounted for nearly one quarter of the total claims for drugs
considered potentially risky for elderly patients, the team
reported. Neuromuscular agents ranked second among the most
commonly prescribed classes of Beers list drugs.

The results mirror those of an earlier study of
prescriptions to the elderly in 1987, which found that 23.5
percent of elderly patients filled prescriptions for one or
more of the Beers list drugs, Curtis added. "Despite earlier
warnings, we're not getting any better in the use of these
drugs," she said.

The findings suggest that some doctors may be uninformed
about the increasing risks presented by common medications as
people age, Curtis said. Others might be familiar with the
list, but believe that the benefits outweigh the risks in some
situations, she added.

The team notes that pharmaceutical claims databases could
offer a useful tool to help reduce the problem by screening
prescriptions and issuing patient-specific alerts when
physicians prescribe inappropriate drugs or drug combinations,
she said. Physicians' compliance with the guidelines might also
be improved by bolstering the clinical evidence for the risks
presented by particular drugs when taken by older patients, she
added, noting that the elderly are rarely included in the
clinical trials that generate information about drugs' side
effects.

Archives of Internal Medicine published a more recent update
of the Beers list including 48 medications or classes of
medications to avoid in adults age 65 or older in their Dec. 8,
2003, issue.

Collaborators on the study include Truls Ostbye, M.D., and
Veronica Sendersky, of Duke; Steve Hutchison, Ph.D., Peter
Dans, M.D., and Alan Wright, M.D., of AdvancePCS; and Raymond
Woosley, M.D., of University of Arizona Health Sciences
Center.

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