I like to drink grapefruit juice. I hear that it can get in the way of some prescription medicines. Is that true?

Answer From Katherine Zeratsky, R.D., L.D.

Yes. Grapefruit can get in the way of several kinds of prescription medicines. So can other citrus fruits, such as pomelos, tangelos and Seville oranges, which often are used in marmalade.

Mixing grapefruit with some medicines can cause serious health problems. If you take prescription medicines, ask a health care professional, such as a doctor or pharmacist, whether it's OK to eat grapefruit or other citrus products while taking the medicines.

You may need to cut grapefruit products from your diet. In most cases, you can't just take your medicine at a different time from when you eat grapefruit. But you can ask your health care professional if there's another medicine you can take that works with grapefruit.

The problem is that chemicals in the fruit can get in the way of the medicine breaking down, called metabolizing, in the digestive system. As a result, the medicine can stay in the body for too long or too short a time.

More often, the problem is medicine staying in the body too long. Medicine that stays in the body too long can build up to risky levels and cause more side effects. A medicine that breaks down too quickly won't have time to work.

The U.S. Food and Drug Administration requires that some medicines include warnings about eating grapefruit or drinking grapefruit juice while taking the medicine. Often-prescribed medicines that can interact with grapefruit include medicines that:

  • Fight infection.
  • Lower cholesterol.
  • Treat high blood pressure.
  • Treat heart problems.
  • Prevent the body from rejecting a donated organ.
  • Treat anxiety.
  • Treat seasonal allergies.
  • Control seizures.
  • Ease motion sickness.
  • Treat not being able to get or keep an erection, called erectile dysfunction.
  • Replace hormones.
  • Reduce cough.
  • Control pain.

To be safe, always talk with a health care professional, such as your doctor or pharmacist, when you get a new prescription. Ask if there's a problem if you take it with any foods or with other medicines. If the answer is yes, ask if you need to remove foods from your diet or change the way you take other medicines.

July 13, 2023