As many as 3,300 Canadians over the age of 65 die every
year due to adverse drug reactions (ADRs), according to
an analysis of Health Canada's ADR database by the CBC.
Some of these deaths are unavoidable consequences of caring
for an already-frail population, but studies show that
many of them could have been prevented.
Writing up a script is the most
common medical intervention. But when it comes to elderly
patients, the wrong drug, the wrong dose or too many
different medications can lead to deadly mistakes. "You
can't change the fact that older people have all these
health issues, but you can control the drugs you give
them," says Dr Paula Rochon, a geriatrician at the Baycrest
Centre for Geriatric Care in Toronto.
BEERS
WHAT?
Some classes of drugs should always be avoided for the
elderly because the risks outweigh the benefits. There
are often better, safer alternatives. These risky meds
make up the so-called Beers list, named after Dr Mark
H Beers, editor of the Merck Manual for Geriatrics,
who first compiled the peer-reviewed list in 1991. Trouble
is many docs don't even know the simple-to-use list
exists. In 2004, more than 1.5 million Canadians over
65 were given a drug on the Beers list, according to
the CBC.
"Things like antipsychotics, anticoagulants
and diuretic therapies are often associated with adverse
events," says Dr Rochon. Yet these drugs are routinely
prescribed. In a study of Ontario nursing home residents,
Dr Rochon found that nearly 25% were given antipsychotics
within one year of admission. "If we know these drugs
are problematic," she says, "it begs the question, why
are they used so often." Certain types of anti-anxiety
meds that stay in the body for prolonged periods of
time, muscle relaxants that can cause sedation and weakness,
and barbiturates, which are highly addictive, should
also be used sparingly in elderly patients.
But staying away from drugs on
the Beers list isn't enough. "The issue of adverse drug
events is way bigger than the Beers list," Dr Rochon
says. "It's just a marker that there's a problem."
PRESCRIBING
CASCADE
Seniors are taking, on average, between two and six
prescription drugs and one to three OTC drugs regularly.
Polypharmacy increases the risk of drug interactions,
noncompliance and medication errors — all factors
that can lead to oft-unnecessary danger. "Drugs aren't
always the best solution," says Dr Rochon. "You have
to look at everything they're taking, give them what
they really need and take away what they don't." This
includes OTC drugs, herbal remedies and supplements,
which should always be counted in the audit of a patient's
meds.
The 'prescribing cascade' is a
frequent cause of overmedication in the elderly. This
begins when an ADR is misinterpreted as a new medical
condition. Another drug is then prescribed, placing
the patient at risk of developing additional adverse
effects because of a treatment that may not even be
necessary. To avoid this scenario, Dr Rochon suggests
considering other options. Exercise and weight loss,
for example, instead of an anti-inflammatory for arthritis
pain.
Seniors are naturally frailer and
more vulnerable to the effects of drugs: age-related
changes in gastric pH and gastrointestinal motility
as well as in hepatic and renal function all affect
how an older person will react to medication. That's
where dosage considerations come in. "You always start
with very low doses and titrate up," says Dr Rochon.
A
LESSON FROM LONGTERM CARE
In the fall of 2004, Dr Rochon and her colleagues at
Baycrest got a computerized system to help doctors prescribe
better and minimize adverse events. Nursing home residents
are 48% less likely to receive drugs on the Beers list
than those who are community-dwellers, according to
a study by Dr Rochon in the June 2004 issue of the Journal
of the American Geriatrics Society. She attributes
this in part to better communication between doctors
and pharmacists. Every three months, Baycrest's pharmacist
and doctors review a list of all the drugs a given patient
is taking. "That doesn't happen in the community," explains
Dr Rochon. "It's not easy to make it happen, but it
is possible."
Things are happening. In Ontario,
the Ontario Drug Benefit (ODB), which provides people
over 65 free meds, tracks their drug claims. In September
2005, the Ministry of Health launched a pilot project
providing most Ontario EDs with electronic access to
those files. Dr Rochon applauds the initiative and hopes
they'll take it even further. "It's the kind of information
that would be really helpful to frontline doctors and
caregivers." A Canadian version of the Beers list is
available at www.cbc.ca/news/background/seniorsdrugs/beers_table_more.html
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