What is a medication-food interaction?

Food is necessary for life, and medications are important for treatment of many health problems. However, when mixed together they may combine in a way that either makes the medication less effective or keeps important nutrients from being used by the body. Drug and food interactions can happen with both prescription and nonprescription (or over-the-counter) medications such as widely used antacids, vitamins and iron pills.

Are all medications affected by the food we eat?

No, but many can be affected not only by what we eat, but also by when we eat. To ensure that medications are safe and effective, carefully follow your health provider’s and pharmacist’s instructions.

How do drugs and food interact?

Certain foods, beverages, alcohol, caffeine and even cigarettes can interact with medications. Many individual factors such as dose, age, weight, gender and overall health may influence their effectiveness.

Some foods may decrease the absorption of medication. Tetracycline is a good example of a group of related antibiotics that are labeled “cyclines,” and whose absorption is significantly inhibited by milk and dairy products. Other medications which treat mild to moderate pain and fever, such as acetaminophen, are better absorbed if taken on an empty stomach.

Some foods may also increase the absorption of medication. Orange juice is a good example of food rich in vitamin C, which helps the body absorb more iron.

Alcohol increases drowsiness and slows mental and motor performance if taken with antihistamines, medications used to relieve or prevent the symptoms of cold and allergies.

Some drugs may increase or decrease appetite. For example, drugs used in the treatment of cancer frequently cause nausea and vomiting; and insulin, steroids and certain antihistamines can cause a person to feel hungrier than normal.

Some drugs interfere with the absorption of important nutrients in food. For example, mineral oil used for constipation prevents absorption of fat-soluble vitamins A, D, E and K.

Some medications can irritate the stomach, so it is best to take them with food or milk.

Remember: Not only can medications interact with food and alcohol, they can also interact with each other.

Tips to remember about medication-food interactions

  • Make sure your health care provider knows about every medication taken regularly or occasionally, including over-the-counter ones.
  • Read directions, warnings and interaction precautions printed on all medication labels and packages, including over-the-counter remedies. If you need more information, ask your health care provider or pharmacist.
  • Follow directions and take medication as prescribed.
  • Take medicine with a full glass of water.
  • Do not mix medication with food or take capsules apart unless told to do so by your health care provider.
  • Do not take vitamin pills at the same time you take medications, because vitamins and minerals can interact with some drugs.
  • Never take medication with hot drinks because the heat may destroy its effectiveness.
  • Never take medication with alcohol.
  • If your child attends child care or school, discuss ways of reducing the number of medications and doses with your health care provider.