September 7, 2018

How to Avoid Medication Interactions As You Age

As your age increases, it's likely that your arsenal of over-the-counter drugs, prescription medications and dietary supplements will grow, too. But before you pop your next pill, ask yourself: Is your drug regimen safe?

A new study published in JAMA Internal Medicine found that nearly 70 percent of older adults are using at least five medications or supplements at the same time, a significant increase in recent years.

Problematic Combinations

Seniors face a growing risk for major drug interactions. Patients who are on at least six medications have an 80 percent chance of a drug interaction, and 1 in 5 hospitalizations of elderly patients is related to drug interactions, says Alexis Eastman, MD, clinical medical director of UW Hospitals and Clinics' Division of Geriatrics.

"Each time you add a new medication you're adding to your risk," Eastman says.

So why are older patients taking more medications than ever? Discovery of new treatments, increase in drug insurance coverage and expansion of lower-cost generic drugs all play a role, notes Korey Kennelty, PharmD, PhD, an advanced geriatric fellow and pharmacist in the Geriatric Research Education and Clinical Center at William S. Middleton Memorial Veterans Hospital.

Medication Interactions to Watch For

And a lot of those medications may be necessary. Patients are living longer, and rising rates of obesity drive the need for cholesterol, blood pressure, reflux and diabetes medications.

Examples of medication interactions to watch for:

  • Warfarin, an anticoagulant, can increase your risk of bleeding when used with ibuprofen or naproxen.

  • Levitra, which is used for erectile dysfunction, can cause very low blood pressure and dizziness when paired with nitroglycerin, which is used to treat heart conditions.

  • Combining a muscle relaxant and an opiate pain reliever can cause a sedative effect and increase your risk for a fall.

Some medications and supplements can also counteract others. For example, calcium supplements can prevent your body from absorbing certain antibiotics properly and can also hinder the effectiveness of thyroid medications. Taking those medications at different times of the day can help.

Increasing Side Effects

Medications also can cause side effects and lead to what's called "a prescribing cascade." For example, a patient who regularly takes a nonsteroidal anti-inflammatory drug such as ibuprofen (e.g., Advil or Motrin) or naproxen (e.g., Aleve) may experience high blood pressure without realizing the medication is the culprit.

Adults in their 50s and older are more vulnerable to serious drug side effects and interactions.

"It's a snowball effect where you're taking a medication that causes a side effect and then you are placed on another medication to treat that side effect," Kennelty says.

Adults in their 50s and older are more vulnerable to serious drug side effects and interactions. That's because physiological changes, such as reduced kidney and liver function, reduced muscle mass and increased fat, all affect how your body processes medications.

"As we get older, the risk of medication side effects goes up. So dry mouth, constipation, dizziness — those are all things that increase as you get older," Eastman says.

Drugs that are stored in the body's fat can last longer in an older adult, making a 24-hour drug linger for 72 hours instead. In addition, the protective blood-brain barrier can become leakier, making a medication even more potent.

"Benadryl, which can make a 20-year-old sleepy, can make an 80-year-old delirious," Eastman says.

Dry mouth, confusion and agitation, and urinary retention can be side effects of anticholinergic medications, a category that encompasses a wide variety of prescription and over-the-counter drugs, including some antihistamines and medications prescribed for heart arrhythmias, Parkinson's, and overactive bladder. Anticholinergic medications have also been linked to brain damage and dementia.

"Anticholinergic medications can have pretty devastating side effects in older adults," Kennelty says.

You may not even realize your medication is causing a side effect, but that dry cough could be related to your ACE inhibitor drug instead of a lingering cold.

"If you can't explain a symptom, reach out to your health care team, particularly your pharmacist," Kennelty says.

Tips to Use Medication Safely

Here are some other ways to ensure that you and older loved ones are using medications safely:

  • Don't assume that over-the-counter products are safe. There are more than 100,000 over-the-counter drug products marketed, which include about 800 active ingredients, Kennelty notes. Because many over-the-counter products may contain the same active ingredient, using more than one medication at a time could expose you to higher levels of that ingredient. Herbal supplements can also cause side effects.

  • Ask questions. "You need to advocate for yourself," Eastman says. "I think every patient should know the reason for every medication and know what the risks are. Ask ‘Why? Do I really need this? Is this really going to help me?'"

  • Use your pharmacist as a resource. And it doesn't have to be a quick conversation at the pickup window. Many community pharmacies offer medication therapy management services, which could include an in-depth medication therapy review to identify any medication-related problems such as therapeutic duplications, potential adverse effects or interactions. This service may be covered by your insurance. Ask your community pharmacist if this is an option, Kennelty suggests.

  • Review your medications at your annual checkup. Make sure to mention over-the-counter medications, vitamins, herbals, creams, ointments and eye drops, too. "Many patients will assume the health care provider knows everything they're taking. Don't assume; be proactive," Kennelty says.

  • Always keep an updated medication list in your wallet or purse. Include the medication name, dose, how often you take it, what you take it for, the date the medication list was last updated, and your drug allergies. "If you're going to the emergency room or urgent care, it's a lot easier to hand them an updated medication list instead of trying to remember everything," Kennelty says.

  • Always read the labels. You might think it's the same medicine you've been using for years, but formulations and doses can change.

  • Use pill boxes (instead of your prescription bottles) to avoid accidental overdose. "It's hard to keep track of which little white pill you take at which time, so it's easy to take two accidentally," Eastman says.

  • Consult a physician or pharmacist before stopping a medication cold turkey. That's particularly important with muscle relaxants and pain, mood and memory medications, which affect the brain. "Not all medications can be stopped quickly and safely," Eastman says. "You don't want to run the risk of withdrawal."

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