Dairy products, antacids, and iron preparations prevent some medications from being properly absorbed into the body. If the medication is not properly absorbed, it may be less effective. Medications that are affected this way include:

  • Certain antibiotics (demeclocycline, tetracycline, ciprofloxacin, norfloxacin)
  • Certain medications used to treat osteoporosis (etidronate, risedronate)

Other medications may also interact with dairy products, iron, and antacids. Check with your pharmacist to find out whether this is true for your medication. If so, avoid taking or eating the following items within two hours of taking your medication:

  • Dairy products (milk, cheese, yogurt, ice cream, butter): These products contain large amounts of calcium, which can react with some medications and prevent them from being absorbed into the body.
  • Calcium supplements: Calcium can be found in multi-vitamins, over-the-counter medications, and prescription medications (e.g., calcium carbonate, calcium gluconate, calcium citrate). Calcium can react with some medications and prevent them from being absorbed into the body.
  • Iron-containing products: Iron may be found in multi-vitamins, over-the-counter medications, and prescription medications (e.g., ferrous sulfate, ferrous gluconate, ferrous fumarate). Like calcium, it can react with some medications and prevent them from being absorbed into the body.
  • Antacids: These products usually contain either calcium, aluminum, or magnesium. Any of these can interact with some medications and prevent them from being absorbed into the body.