Grapefruit Juice and Medicine

Republished November 14, 2024

Have you ever heard that drinking grapefruit juice can interfere with certain medicines? Well, it is true. But, do you know why and which medicines you shouldn't be taken with grapefruit juice?

Drinking grapefruit juice with certain medicines can cause too much of the medicine to get into your body. Grapefruit juice contains certain chemicals that block important enzymes in your small intestine. These enzymes are important because they normally break down the medicine. Without this enzyme working properly, too much medicine can build up in your body.

While it has been known that grapefruit juice can cause too much of certain medicines to enter the body, more recently, studies have show it can also have the opposite effect. For example, taking certain allergy medicine, such as Allegra Allergy (fexofenadine), can cause too little medicine to enter the body. This can result in the medicine not working as well. Studies have shown that with some medicines grapefruit juice can affect proteins that are supposed to "transport" the medicine into the body which results in not enough medicine entering the body.

Here are some examples of medicines that may be affected if taken with grapefruit juice:

• Lipitor (atorvastatin) and Zocor (simvastatin): cholesterol-lowering medicines
• Procardia XL: medicine to treat high blood pressure
• Neoral and Sandimmune (both cyclosporine): organ transplant rejection medicines
• buspirone: anti-anxiety medicine
• Tampeyo and Uceris (both budesonide): medicines to treat Crohn's disease or ulcerative colitis
• Pacerone (amiodarone): medicine to treat abnormal heart rhythms
• Allegra Allergy (fexofenadine): antihistamine

Please note that not all medicines in each category listed above, such as cholesterol-lowering medicines of high blood pressure medicines, are affected by grapefruit juice. Only specific medicines are affected.

Here's what you can do: If you are taking prescription or over-the-counter (OTC) medicines, ask your pharmacist or doctor whether it is safe to drink grapefruit juice. Read the medication guide that comes with your prescription medicine to see if grapefruit juice affects it. Read the Drug Facts label on OTC medicines to see what food or juice should be avoided. In addition, Seville oranges, tangelos, and pomelos may have similar affects as grapefruit and grapefruit juice on medicines and should be avoided. For more information, check out this short video from the US Food and Drug Administration (FDA)