What’s in your medicine cabinet? Is it filled with several medicines prescribed by different doctors and an array of over-the-counter drugs? The older you are, the more likely you are to take several medicines a week, according to several reports from the Slone Epidemiology Center at Boston University. In fact, if you’re over 65, there’s good chance you take five or more prescription medicines a week to treat osteoarthritis (OA) and other health conditions.

Taking more than one medicine to treat a single condition or to manage multiple health issues is called “polypharmacy.” Polypharmacy, among older adults in particular, is a growing concern as it raises the risk of dangerous side effects and drug interactions.

 “Sometimes, a person sees multiple specialists and each doctor prescribes medications, so you get some overlap or duplication,” says Donald Miller, PharmD, professor and chair of pharmacy practice at North Dakota State University in Fargo.

Even if you faithfully stick to your doctors’ instructions and closely follow the directions for taking each drug, you could still unknowingly be taking medicines you don’t need or worse – you could be combining drugs that can have unintended interactions, says Miller.

Risks of Taking Multiple Medicines

Many of the drugs you take for arthritis and other conditions can potentially interact with one another. “The effect of one drug can be boosted or partially cancelled out by another,” explains Miller.

Here are two examples:

  • Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Motrin) and naproxen (Aleve) can hurt your kidneys. Take an NSAID with painkillers, diuretics or other drug that affects the kidneys, and you increase your risk of kidney damage.
  • NSAIDs reduce the effectiveness of medicines used to treat high blood pressure and certain heart conditions.

Your age also plays a role in how drugs interact. As you get older, your metabolism slows, which means it takes longer for your liver to break down and remove each drug from your body. “Medicines that normally don’t interact with each other will now do so because they are in your body longer,” says William F. Harvey, MD, assistant professor of medicine and clinical director in the Division of Rheumatology at Tufts Medical Center.

You might not even realize that you’re mixing drugs, especially when you take over-the-counter medicines. For example, many multi-symptom cold relievers and headache remedies contain NSAIDs or acetaminophen, ingredients that may not be obvious on the front of the package. Adding these products to an NSAID or acetaminophen your doctor has already prescribed could lead to a potential overdose.

Certain “all-natural” herbal remedies also can have dangerous interactions with drugs often prescribed for OA. Taking supplements containing ginkgo, ginger, or dong quai along with NSAIDs can increase the risk of gastrointestinal bleeding. Some Chinese herbs can contain high doses of anti-inflammatory medicines.

The Pharmacy’s Role in Medication Management

Doctors typically go over their patients’ medicines whenever they prescribe a new drug, as well as at follow-up visits. “But sometimes if you have multiple doctors, no one knows what the other one is doing,” says Miller. “That’s where the pharmacist can come into play.”

“Pharmacists are really another layer of defense,” says Dr. Harvey. Going to a pharmacist who is familiar with your medication history can bolster that defense.

“If you can stick with one pharmacy you trust, the staff can constantly be looking out for your welfare on medications,” explains Wendy Brown, PharmD, associate professor in pharmacy practice at North Dakota State University.

Your pharmacist can go through your medicines—including OA meds, over-the-counter drugs and herbal remedies—to make sure they’re appropriate for you, and to identify potential side effects and interactions. It is a service known as medication therapy management, or MTM.