For people ages 65 and older, drug safety takes on special importance. Older adults are more likely to experience side effects from prescription drugs than young people are, partly because of physiological changes in the body that commonly accompany aging.
Also, it’s common for older people to be on multiple medications. People ages 65 and older comprise only 13 percent of the population but consume 30 percent of all prescription drugs. The average older adult takes between three and five prescription drugs, and many older adults take over-the-counter medications and supplements as well.
For older people, it’s especially important to take only the minimum effective dose of all drugs. Younger people have a greater margin of safety for larger doses of prescription drugs because their livers and kidneys are in prime condition to remove medication from the blood. In older adults, however, reduced liver and kidney function can impair the ability to remove unused or excess drugs from the blood. The medication “left over” from one day to the next can build up in the blood. Eventually, the drug’s blood concentration may become high enough to cause side effects.
Medications can also become more concentrated and have a stronger effect than they would in someone younger. Older bodies have more fat relative to bone and muscle. So when an older person takes a drug that dissolves in fat, the medication may become trapped in the body fat, making less of it available to treat the illness.
Changes in digestion with age can also affect drug metabolism. For example, older people’s stomachs may produce less digestive acid. This means that when an older person takes a drug that dissolves in acid, the drug takes longer to break down and be absorbed than it would in the body of a younger person.
In older adults, blood flow through the body may slow because of cardiovascular disease. Impaired blood flow through the brain makes people more vulnerable to drug side effects like dizziness, fainting, loss of coordination and confusion. This is a serious risk for the frail elderly, or “older old,” for whom losing balance can be fatal.
The best defense is knowing as much as you can about the drugs you take. And at least once a year, put all your drugs—prescription, over-the-counter and dietary supplements—into a bag and bring them with you to your doctor’s office. Alternatively, you can keep a running, detailed list of drugs, dosages and instructions for use.
A safety resource: The Beers Criteria
In 2012, a panel of experts in geriatric care released an updated reference listing 53 medications or medication classes that pose potential risks for adults 65 and older—risks that outweigh potential benefits. Called the Beers Criteria for Potentially Inappropriate Medication Use in Older Adults (informally known as the Beers Criteria), the compendium was initially created more than 20 years ago by a geriatrician, Mark H. Beers, to help guide doctors in prescribing drugs for older patients.
The 2012 Beers Criteria, published in the Journal of the American Geriatrics Society and updated again in 2015, established the following three groups of potentially inappropriate medications. Experts identified:
■ 34 drugs and types of drugs that pose a high risk of side effects or appear to have limited effectiveness in older adults—and for which there are alternative medications or nondrug remedies.
■ Medications for 14 common diseases or disorders that, in older people, may worsen the problem being treated.
■ 14 types of drugs that, even though their risks may outweigh benefits, may still be the best choice for a particular individual—but should be used only with caution and careful monitoring.
Just because a drug is listed in the Beers Criteria doesn’t mean you shouldn’t be taking it if you’re over 65. It’s included in the criteria because it’s thought to have an increased risk—but it isn’t necessarily unsafe for all older adults. You may not experience side effects or, even if you do, that drug may be the best option available for treating your problem—a decision that you and your doctor should make.
Discuss any Beers Criteria drug with your doctor, both to understand its most frequent and serious side effects (which applies to any drug you’re taking) and to ask whether a safer or more effective alternative is available.