A Dose of Caution on Medicines
Marcelle Adolph, 84, had just finished breakfast, downing nine of the 11 prescription pills she takes every day. Moments later, she was slumped over in her chair.
“I was sitting in the kitchen, and I didn’t feel right,” the West Los Angeles resident said. “The next thing I knew, paramedics were shaking me to awaken me.”
In the emergency room, Adolph learned that the dosage of her anti-diabetic drug was too high, causing her blood sugar level to drop so low she blacked out.
Adolph’s story, experts say, highlights a serious but largely understudied problem: Elderly people are at higher risk for adverse drug reactions than younger adults.
“Although it’s difficult to assign an exact number to this problem, it does represent a common and often preventable cause of hospitalization for the elderly,” said Dr. Jerry Avorn, a geriatrician and associate professor of medicine at Harvard Medical School.
“Sometimes, adverse drug events in the elderly are mistaken for normal aging or some other disease,” Avorn said. Slurred speech or loss of balance, for example, may be mistaken for symptoms of Parkinson’s disease rather than side effects of tranquilizers.
As people age, kidney and liver functions begin to decline, putting the elderly at greater risk for drug-related problems. In addition, it often takes longer for older people to metabolize the same drug dosage that a younger person might easily tolerate.
The elderly also are far more likely to suffer from multiple ailments for which several prescription drugs must be taken at the same time, increasing the risk of disabling, sometimes fatal, interactions.
Too often, doctors prescribe potentially risky medications when safer alternatives exist. According to a 1995 federal report, 17.5% of non-institutionalized Medicare recipients used at least one drug considered unsuitable for elderly patients.
The financial toll is formidable. In an article published last year in the Archives of Internal Medicine, researchers estimated that the health care costs of drug-related death and illness for nursing home residents alone ranged from $4 billion to $7.6 billion a year in the United States.
Meanwhile, the variety of medications available for the older population is growing considerably. Pharmaceutical companies are testing 178 new drugs that target symptoms of aging, 46 more than in 1995.
Some doctors and patient advocates worry that as more drugs are thrown into the mix, the chances for error will increase.
“We look forward to new therapies,” said Daniel Perry, executive director of the Alliance for Aging Research in Washington, D.C. “There are more and more drugs allowing people to enjoy the quality of life, and those are adding on to those that maintain life. But, every time another drug is taken, you’re increasing the risks of adverse side effects.”
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Although older people consume a significant proportion of both prescription and over-the-counter drugs, doctors know relatively little about how these medications interact. Older people traditionally have been underrepresented in clinical trials, even in studies of drugs that treat diseases common in old age.
A recent survey of 214 coronary disease trials found that only 40% of the studies included persons over age 75. Similarly, another survey of 112 trials for Parkinson’s disease found that only 38% included subjects over 75.
Nine years ago, the U.S. Food and Drug Administration established guidelines encouraging the inclusion of elderly subjects in drug trials. Dr. Robert Temple, associate director for Medical Policy at the FDA’s Center for Drug Evaluation and Research, said the drug industry has largely complied with the regulations, which are not mandatory.
But many experts want more information about the very old, who remain underrepresented in studies. “There are some people over the age of 65 in the trials, but not frail 85-year-old nursing home residents using multiple drugs,” Perry said.
Some researchers and physicians question the practicality of including older subjects with more complex health problems in clinical trials. A complicated medical history may hide the true effect of drugs, and older people may be more likely to drop out of studies. In addition, it may not be ethical to subject infirm patients to the risks some trials carry, critics warn.
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“It’s not appropriate to kill a person to see what the effects of a medication are,” said Dr. Lodovico Balducci, program leader of the Senior Adult Oncology Program at the H. Lee Moffitt Cancer Center in Florida.
Balducci cited the example of cancer treatment. While life-prolonging cancer trials usually involve more aggressive treatment, “for the frail, you try to use palliative measures to relieve symptoms of cancer.”
Balducci added that many of the very old who might qualify for trials are not interested in participating.
“The majority of older people who are 85 are not really that frail, and they deserve clinical trials,” he said. “But many grew up in a different era where doctors knew everything. The concept of clinical randomization . . . makes them feel like they are guinea pigs.”
Finding ways to include older subjects in studies is just one challenge. Another is simply keeping track of all the drugs an older patient might take.
Andrew Smith, senior health policy analyst at the American Assn. of Retired Persons and an expert on preventing medication errors, said it is easy to lose essential medication information when patients transfer from one care setting or one pharmacy to another.
Some drug-related interactions can be avoided with simple, practical steps. Patients should, for example, keep a list of all the drugs they are taking, including herbal and over-the-counter medicines.
Adolph keeps a list of her medications, but she said it’s still difficult to keep track of them. When she ran through her list of pills, she was unable to recall what conditions two of the medications treated. At times she loses track of which pills she’s taken.
“Sometimes I leave the pill on the counter and I just swallow water,” she said. “When you’re not feeling well, you’re a little confused. It’s very difficult.”
Some pharmacies color-code containers to help patients such as Adolph manage their drugs.
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Still, more health care professionals need to be trained in dealing with the special needs of an older population, Perry said. A survey conducted by the Alliance for Aging Research revealed that only two out of 126 medical schools around the nation have full departments of geriatrics, and only 11 require courses devoted solely to geriatrics.
There have been relatively few incentives for people to pursue geriatrics, said Dr. Seth Landefeld, chief of the division of geriatrics and chair of the center on aging at UC San Francisco/Mt. Zion Medical Center
“People who decide what they’re going to do in medical school are almost all very young,” Landefeld said. “It’s easier to identify with middle-aged folk than frail, nursing home residents.”
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Common Hazards
Some common medicines are potentially dangerous for the elderly. Experts warn that patients should not stop any medication without consulting a physician.
Prescription Drug: Propoxyphene (Davron, Darvocet)
Use: Controls pain
Potential risks: Confusion, interference with respiration
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Prescription Drug: Amitriptyline (Elavil)
Use: Treating depression
Potential risks: Dizziness, dry mouth, difficulty urinating, constipation, confusion
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Prescription Drug: Flurazepam (Dalmane)
Use: Treating insomnia
Potential risks: Takes a long time for elderly to metabolize; can produce prolonged sedation, leading to falls and fractures.
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Prescription Drug: Chlorpropamide (Diabinese)
Use: Treating diabetes
Potential risks: Takes long time to metabolize, can cause low blood sugar.
Over-the-Counter Drug: Diphenhydramine (Benadryl)
Use: Runny nose
Potential risks: Urinary retention, constipation, dizziness, confusion
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Over-the-Counter Drug: Chlorpheniramine (Chlor-Trimeton)
Use: Same as Benadryl
Potential risks: Same as Benadryl
Sources: Archives of Internal Medicine, Volume 157, July 28, 1997, by Dr. Mark Beers, senior director of Geriatrics and editor of The Merck Manuals; Dr. Jerry Avorn, associate professor of medicine at Harvard Medical School.
