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Understanding Drug Side Effects as You Age

As your metabolism changes, common meds may trigger new, unwelcome reactions

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While you've probably given your metabolism some thought when it comes to midlife weight gain, your digestive process affects other things, too — including how your body handles any drugs you take.

“Your metabolism changes a lot as part of the normal aging process,” explains internist Michael Hochman, clinical associate professor of medicine and director of the University of Southern California Gehr Family Center for Health Systems Science. “Your liver breaks things down differently, your kidneys stop being as efficient, and your GI system works a little more slowly. That means a medication that your body may have had no trouble metabolizing when you were middle-aged becomes more problematic as you get older.” As a result, you'll be more susceptible to possible side effects from the medications you take than someone a decade or two younger, he says.

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Overall, 1 in 6 adults over age 65 are likely to have a harmful reaction to one or more of the meds they're popping, according to the American Geriatric Society. (And this age group is popping quite a few, it seems. More than a third of Americans over age 62 now regularly take more than five prescription medications, according to a JAMA Internal Medicine study.)

This doesn't mean you should go cold turkey on your meds or shy away from taking a drug if you need it. But if you're taking any of the following five types of drugs on a regular (or semi-regular) basis, have a chat with your doctor, pronto. Together, the two of you may be able to come up with some alternatives.


Women over age 60 who take antibiotics more than rarely (a total of at least two months of use over a seven-year period) are 32 percent more likely to suffer a heart attack or stroke than those who use them less frequently, according to a Harvard study published in April in the European Heart Journal.

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"We think this is because antibiotic use changes gut bacteria, which in turn leads to changes in metabolites, which are certain substances in the bloodstream that raise risk of heart disease,” explains internist and study coauthor JoAnn Manson, chief of the Division of Preventive Medicine at Brigham and Women's Hospital in Boston.

What to do: The next time your physician prescribes an antibiotic, ask if you really need it. Nearly a quarter of antibiotics prescribed are unnecessary, according to a study published this year in the British Medical Journal. “Sometimes a doctor will prescribe an antibiotic because the patient asks for it, but oftentimes, like in the case of a lingering cold caused by a virus, it really won't do anything,” Manson points out. But if you do need an antibiotic, don't cut the course short, even if you feel better. You should take any antibiotic exactly as prescribed. This will reduce chances of the bug coming back.

NSAIDs (nonstreroidal anti-inflammatory drugs)

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Research shows that almost all folks over 65 take over-the-counter NSAIDs (nonsteroidal anti-inflammatory drugs) such as ibuprofen, but people in this age group should limit their use to once or twice a month — if at all — says Michael Steinman, a geriatrician and professor of medicine at the University of California San Francisco. “We don't recommend more frequent use, because they increase the risk of bleeding stomach ulcers,” he says. They also may raise your blood pressure, affect your kidneys and worsen heart failure.

What to do: If you have an ache or pain, pop acetaminophen (Tylenol) instead, Steinman says. Just make sure not to go over 3000 mg per day, or the equivalent of six pills. If you do need to take an NSAID, talk to your doctor about possibly taking it with an over-the-counter proton pump inhibitor such as omeprazole (Prilosec). These drugs help reduce the risk of stomach bleeding.

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Sleeping pills and anti-anxiety meds

Almost a third of older American adults take sedatives. These include prescription sleeping pills such as zolpidem (Ambien) and eszopiclone (Lunesta), as well as anti-anxiety medications such as alprazolam (Xanax) and diazepam (Valium). And use of such drugs carries a lot of risk for this age group. “Since they stay in seniors’ bodies for longer, they're more susceptible to side effects like falls, dizziness, confusion and memory problems,” Hochman says. Taking them doubles the risk of falls and hip fractures.

What to do: It's fine to pop an Ambien if it's a once-in-a-while event, for example, if you need to catch some shut-eye on an especially long flight. But if you find that you're relying on sedatives for more than a day or two, talk to your doctor. “You may have an underlying condition such as depression or anxiety that should be treated,” Steinman says. Another option: cognitive-behavioral therapy (CBT), a form of behavioral treatment that focuses on changing habits such as those that disrupt sleep. The American Academy of Sleep Medicine (AASM) now recommends CBT over sleep drugs as the treatment of first resort for chronic insomnia. This type of short-term counseling usually requires only six one-hour sessions and is often covered by insurance. Some sleep centers offer CBT; to find one accredited by AASM, go to

Certain over-the-counter antihistamines

Products such as nighttime cold medications that contain the antihistamines diphenhydramine (Benadryl) and chlorpheniramine (AllerChlor, Chlor-Trimeton) can cause symptoms such as confusion, blurred vision, constipation, trouble urinating and dry mouth. And long-term use may also raise your risk of dementia, according to a study published in JAMA Internal Medicine. This is because these medicines are anticholinergic drugs, which means they block the action of acetylcholine, a substance in the brain linked to learning and memory.

What to do: Always read the ingredient labels on all the OTC cough, cold and allergy medications you buy, Hochman says (diphenhydramine is often found in nighttime cold medicines, for example, because it dries up nasal secretions while also making you sleepy). If you're plagued with something like hay fever, look for an OTC antihistamine that contains ingredients such as loratadine (Claritin) or cetirizine (Zyrtec), which don't have anticholinergic effects, he advises. Another option: allergy shots. When people ages 65 to 75 got jabbed for three years, it relieved symptoms by 55 percent and decreased the amount of allergy meds they needed by 64 percent, according to a 2016 study published in the Annals of Allergy, Asthma & Immunology.

Some diabetes medications

It's important to get your blood sugar under control if you have type 2 diabetes, because you're especially vulnerable to the disease's complications when you're older. But certain anti-diabetes drugs, known as long-acting sulfonylureas, need to be avoided, Hochman says. That's because they can cause dangerously low blood sugar. These include glyburide (Diabeta, Micronase) and chlorpropamide (Diabinese).

What to do: If you have type 2 diabetes, metformin should be the first-line treatment, Hochman says, along with lifestyle measures like losing weight and exercising. Most of the time, these steps are enough to get your blood sugar under control. If not, other diabetes medications can help. But if your doctor feels that's not enough, it's time to have a conversation. “Some doctors are very aggressive when it comes to blood sugar control, but in older adults, there's good evidence to suggest we don't need to be as strict,” Hochman says. “In fact, we think that in this age group, lowering their blood sugar too aggressively can increase risk of death from heart disease."

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