I like to drink grapefruit juice but hear that it can interfere with some prescription medications. Is that true?

Answers from Katherine Zeratsky, R.D., L.D.

Yes. Grapefruit and certain other citrus fruits and products can interfere with several kinds of prescription medications.

Don't take these interactions lightly. Some can cause potentially dangerous health problems. Check with your doctor or pharmacist before consuming any grapefruit or other citrus products if you take prescription medications. You may need to eliminate grapefruit products from your diet. Simply taking your medication and grapefruit product at different times doesn't stop the interaction.

Problems arise because chemicals in the fruit can interfere with the enzymes that break down (metabolize) the medication in your digestive system. As a result, the medication may stay in your body for too short or too long a time. A medication that's broken down too quickly won't have time to work. On the other hand, a medication that stays in the body too long can increase to potentially dangerous levels, causing serious side effects.

The list of medications that can interact with grapefruit is long and includes commonly prescribed medicines that fight infections, reduce cholesterol, treat high blood pressure and treat heart problems. In addition, researchers are identifying other foods, including other fruits, that may interact with medications.

Play it safe with prescription drugs. Always ask your doctor or pharmacist when you get a new prescription if it interacts with any foods (or other medicines). If the answer is yes, ask whether you need to eliminate that food from your diet.

Jan. 31, 2013 See more Expert Answers