A physician colleague recently treated an elderly patient who presented with signs and symptoms of a bleeding gastric ulcer — abdominal pain; black, tarry stools; and anemia.
The cause was too high a dose of one of the most common over-the-counter pain relievers: ibuprofen (brand names: Advil, Motrin). He had been taking the drug at the same dosage intermittently for decades without a problem, but what he didn't know was that a lower dose would have been more appropriate at his current age (mid 70s).
There is a large body of evidence showing that for many medicines, lower starting or maintenance doses are appropriate for older adults because aging alters drug metabolism and effects. The reason is that many drugs are metabolized by the kidneys, whose function commonly declines with age. So, with age, blood levels rise above desired levels.
Consequently, the 2024 guidance from the Food and Drug Administration directs drug manufacturers to translate decreasing kidney function into dosing recommendations, which is why dosing tables take into account age and renal function in drug labels.
Several of the best-studied examples of drug groups that need age-related adjustments of dose include blood thinners, sedatives (e.g., sleeping pills), certain cardiac drugs that boost heart function, and antidepressants.
It is important for patients to be cognizant of this issue because physicians don't always think about it, especially in patients who have been successfully treated with the same dose of a drug for many years. And physicians are often not involved in patients' decisions about over-the-counter drugs for which a prescription is not required.
For patients who are prescribed a drug new to them, the doctor's mantra is, "Start low, go slow" in increasing the dose. Geriatric pharmacology texts and recently published articles warn that in many older adults, lower starting doses with cautious increases reduce toxicity without sacrificing effectiveness.
In addition to consulting their physicians, elderly patients can avail themselves of resources such as the American Geriatrics Society's "Beers Criteria" for potentially inappropriate medication use in older adults. It provides a comprehensive list of medications that may be dangerous to older people. Such resources flag medicines that should be avoided, dose-reduced or monitored more closely in people older than 65.
While many drugs are lifesaving or improve the quality of life, they can also be harmful, especially in vulnerable populations. Not every medicine needs to be lowered just because someone is older, but many do, and there is solid data to prove it.
In practice, dosage decisions should be individualized based on kidney and liver function, body composition, drug interactions, and frailty. Use the lowest effective dose for the shortest necessary duration. Older adults should be closely monitored when they are taking drugs known to cause problems in the elderly.
Henry I. Miller, a physician and molecular biologist, is the Glenn Swogger Distinguished Scholar at the Science Literacy Project. He was the founding director of the FDA's Office of Biotechnology.