Estrogen in older women and the popular over-the-counter antihistamine, Benadryl, were among those on the list to avoid in the update of the 1997 Beers Criteria, published in the Dec. 8 issue of the Archives of Internal Medicine.
Nonsteroidal anti-inflammatory agents such as Motrin® and Advil®, or ibuprofen, made a second list of medications to avoid in older adults with certain medical conditions; nonsteroidals and aspirin, known to increase the risk of bleeding, were listed as potentially inappropriate for people with gastric or duodenal ulcers. Researchers also added to this list of conditions that increase patients' risk for adverse drug events; additions included cognitive impairment, depression, Parkinson's disease, anorexia, malnutrition and obesity.
Another reason for these increased adverse events is how drugs affect people may change as they age. "As we age, we have more subcutaneous fat, less lean body mass, less total body water; all those things conspire together to lead to increased drug toxicity and overdose," Dr. Fick said.
"The issue that you worry about in older people is changes in the pharmacokinetics of the drugs; how the body actually uses the drug, what the body does to the drug," said Dr. William E. Wade, University of Georgia pharmacist and associate department head for the Department of Clinical and Administrative Pharmacy in the College of Pharmacy. "Renal function changes, which can affect how drugs are cleared from the body. The metabolism can slow down. Often the half-life, or how long the drug stays in the body, changes because of that," said Dr. Wade, a study co-author. That means drugs that were well tolerated for years, may cause problems as people age.
"The single most common problem that I see in my practice comes from the benzodiazepine group of tranquilizers (such as the anti-anxiety medications, Valium and Xanax)," said Dr. Tom W. Jackson, MCG geriatrician and a member of the expert panel that updated the Beers Criteria. "These drugs tend to calm people down and relax them but they also dis-inhibit them. The effects are much like alcohol," said Dr. Jackson, who is on the American Geriatrics Society Board of Directors. "Folks who are on these medications are also much more likely to fall … they are actually four times more likely to fall and break their hip than people who are not on these medications." Dr. Jackson opted to participate in the panel because of the enormous problems he sees in seniors with drugs and drug interactions.
Part of the reason the Beers Criteria was needed was, despite the growing number of people reaching senior status, there are not enough practitioners, such as Dr. Jackson, who specialize in geriatrics and are knowledgeable about the problems, Dr. Fick said. Also, many drug studies do not include older adults and only recently did the body of published work exploring drug use and appropriateness in those adults begin to grow. "There was not enough evidence out there that we could pull and analyze," she said. So Dr. Fick used methodology similar to that used by Dr. Mark H. Beers, editor-in-chief of the "Merck Manual for Geriatrics" and a co-author on the update, to develop the first set of criteria.
She put together a geographically diverse panel of 12 experts, including pharmacists, geriatricians and geriatric psychiatrists, who were familiar with the latest medical literature on the topic and brought their own experience with patients and drugs to the review as well.
The criteria will require continual updating because health care is changing daily, with new medicines, new findings about old medicines and disease, old medicines being discontinued and more, she said.
Some of those discontinued medicines made the list of 15 medications or medication