The majority of victims are the elderly. Why is this so? Older people often have several medical problems for which they see different doctors, each prescribing drugs, often without knowing what other ones the patient is taking.
In the June issue of Emergency Medicine, Dr. Michael Stern, a specialist in geriatric emergency medicine at New York Presbyterian Hospital/Weill Cornell Medical Center, reports the case of a 78 year old woman who was found unconscious after she had taken 12 drugs; prescription as well as a few over-the counter-ones.
The woman had passed out because she had a bleeding stomach ulcer from a combination of drugs that irritate the stomach, Celebrex, ibuprofen and aspirin, and thin the blood, coumadin and aspirin, made worse by an antibiotic that raises blood levels of coumadin.
According to Stern, the elderly take about 40 percent of prescribed drugs, roughly twice what younger adults take, and they suffer twice as many adverse drug reactions as younger people.
"The average community-dwelling older adult takes 4.5 prescription drugs and 2.1 over-the-counter medications," Stern informs.
Polypharmacy is responsible for up to 28 percent of hospital admissions and, he adds if it were classified as such, it would be the fifth leading cause of death in the United States.
Various drugs taken by the elderly can interact dangerously. Some drugs use the same metabolic pathway and, thus, compete with one another, which can result in hazardous blood levels of one or more drugs. Some drugs cause effects like dehydration that reduce kidney function and the ability to eliminate drug metabolites. The combined effects of some drugs can be more potent than the doctor intends, Stern warns.
In addition to seeing several doctors, many older people use multiple pharmacies to buy prescriptions. There may be no single health professional that knows what they are taking and could alert them to dangerous combinations. This is especially true in places where chain stores have replaced independent pharmacies or when the patient's drug plan requires that medications be ordered by mail.
It is not just the number of diseases, drugs or doctors that is the problem. Age-related changes in physiology can worsen matters significantly, even if just two or three drugs are being taken. Just as a child is not the same as a small adult, pharmacologically speaking, an elderly person is not just an older young adult.
Major organ systems function less efficiently in older people. The heart's ability to pump blood declines with age, as does absorption by the gut, the breakdown of drugs by the liver and the ability of the kidneys to excrete them. With aging, the percentage of lean body mass declines, and body fat increases. Thus, aging affects how much of a drug reaches the bloodstream; how well it is distributed in the body and how effectively it is cleared from the system.
For example, says Stern, drugs like digitalis and coumadin, which are primarily distributed in lean tissues, are likely to reach higher blood levels in people older than 65. So the prescribed dosages should be lowered to reduce the risk of toxic side effects. Other drugs, like Valium and barbiturates, that are distributed in fatty tissue can accumulate in the elderly body and remain active longer, increasing side effects like sedation.
Aging also results in fewer protein binding sites for drugs, resulting in a higher blood level of the drug that loses the competition for sites.
In addition, aging can affect the responses to certain medications. This is especially true for those that influence blood pressure and the brain. Drugs like Valium, antidepressants and antihistamines can cause effects like delirium, agitation, sleepiness, depression and worsening dementia in older people, Stern writes.
So how can polypharmacy be addressed?
Keep a list of all medications you take and their dosages and dosing schedules, is what Stern advises. This should include prescription drugs, over-the-counter and herbal remedies and vitamin and mineral supplements. Take the list whenever you go to the doctor, and make sure that the doctor reviews it before prescribing something else. In addition, because doctors are not always familiar with the actions of all drugs, take the list to the pharmacy when ordering a new prescription and ask the pharmacist to review it for potential interactions, he adds.
He also suggests ordering all medications from the same pharmacy, which should keep a computerized record of everything bought.
Stern especially warns against taking an over-the-counter or herbal remedy without checking with the doctor.
Carefully reviewing and abiding by all dosing directions, especially those that say, "Take with food," "Take one hour before meals," "Do not consume alcohol while on this drug," or, "Do not take this medicine if you are also taking..." is what Stern further emphasizes.
Lastly, he recommends asking the prescribing doctor what side effects are to be expected and what should prompt an immediate call to the doctor. "Do not assume that a decline in well-being is caused by a disease or age. It could be a drug side effect", concludes Stern.