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What you need to know about drug interactions

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Before you reach for that bottle of cough and cold medicine, use caution. Anytime you take more than one medication, you risk a drug interaction. This includes prescription drugs, over-the-counter (OTC) medicines, vitamins and herbal supplements.

A drug interaction happens when medications interact poorly with one another. This may make your drugs less effective, increase the effects of a drug, or cause unexpected side effects. That's why it's important to regularly talk to your doctor or pharmacist about all the drugs you are using.

True or false: common drug interactions

Ever year, 1.3 million people External Site end up in the emergency room because of drug side effects, including medication errors, overdoses, allergic reactions and drug interactions. And, 34 percent of people External Site in the U.S. are taking some kind of dietary supplement with a prescription medication.

Test your drug interaction knowledge with this true or false quiz.

  1. Older people are more at risk for drug side effects and interactions.


    People tend to take more medications as they get older, and this puts them at a greater risk for side effects and drug interactions.

  2. OTC pain relievers like naproxen (Aleve®) and ibuprofen (Advil®) should not be combined.


    Avoid using more than one OTC pain reliever at a time unless your doctor says it’s OK. Generally, it’s safe to alternate between different types of pain relievers, so long as you follow dosing instructions.

  3. OTC pain relievers like acetaminophen (Tylenol) and aspirin (Bayer) treat the same symptoms.


    These medications reduce fever and relieve pain, but only medications like naproxen, ibuprofen or aspirin can reduce inflammation (swelling and irritation).

  4. Some prescription drugs are more likely to cause drug interactions, especially when taken with other prescription drugs.


    A few common prescription medications that can cause drug interactions are warfarin (a blood thinner), oral contraceptives and some antibiotics.

  5. Vitamin and herbal supplements are regulated by the Food and Drug Administration (FDA).


    The FDA does not regulate vitamin or herbal supplements like they do drugs or foods. That’s why it’s so important to talk to your doctor about any products you might be taking.

  6. Products labeled “natural” are safe to take with most medications.


    “Natural” does not mean “safe.” Depending on the ingredients, these products can pose unexpected risks when used with certain medications or be dangerous for people with certain medical conditions. For example, taking the herbal supplement St. John’s Wort with certain medications used to treat depression might cause heart problems. Taking warfarin (a prescription blood thinner) with ginkgo biloba (an herbal supplement), aspirin or vitamin E (a supplement) may increase the potential for internal bleeding or stroke.

  7. Certain foods and beverages can cause drug interactions.


    Grapefruit juice causes interactions with several common medications, such as certain statin cholesterol-lowering drugs. Dairy products, antacids, and vitamins with iron can prevent the absorption of certain antibiotics.

  8. It’s safe to drink alcohol while taking an OTC pain reliever.


    First of all, a medicine-alcohol interaction can make you very drowsy. Having three or more drinks a day when taking acetaminophen can cause liver damage. Drinking alcohol when taking aspirin, ibuprofen, or naproxen may cause ulcers.

  9. It’s always safe to take OTC pain relievers with cough, cold and flu medications.


    Many combination cough and cold medicines already contain pain relievers like acetaminophen. Always read the label to make sure you’re not doubling up or getting too much of an active ingredient.

  10. Using the same pharmacy for all your prescriptions makes drug interactions less likely.


    When you get all your prescriptions filled at one pharmacy, your pharmacist has a complete look at all the medications you’re taking, which is more likely to prevent drug interactions.

Three ways to avoid a drug interaction

avoid the risk of a drug interaction
  1. Regularly talk to your doctor(s) about all the drugs you are using.

    This includes OTC medications, vitamins and herbal supplements.

  2. Simplify your drug schedule, and take fewer drugs when possible.

    Before starting a new drug, ask your doctor about other non-drug options that often work as well as drugs, but with less risk.

  3. Talk with your pharmacist.

    Whenever you have a new prescription filled, discuss potential drug interactions.

Two tools you can use today

  1. Call Eight, Four, Four, Eight, Four, Be Well if you have a dosing question or you are worried about a potential drug interaction. BeWell 24/7SM is available at no cost to most Wellmark Blue Cross and Blue Shield members.*
  2. Sign up for myWellmark®. You’ll find personalized tools and resources you need to make smart decisions about your health coverage. If you have prescription drug coverage through Wellmark, you’ll find a drug interaction checker, a pharmacy locator and a tool to check drug costs. Sign up today at Opens New Window.

*BeWell 24/7 is currently not covered by Wellmark’s Medicare supplement plans