Grapefruit and Other Citrus Fruits Can Cause Serious Health Problems With Some Medications
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Grapefruit and Other Citrus Fruits Can Cause Serious Health Problems With Some Medications

Grapefruit and some other citrus fruits interfere with the body's ability to properly absorb medications, leading to potentially dangerous consequences

July 24, 2019

While part of a balanced diet, grapefruit and some other citrus fruits can have serious interactions with certain medications. In fact, there are dozens of drugs known to the U.S. Food and Drug Administration (FDA) that interact with grapefruit alone, including many over-the-counter drugs. If you are taking any medications, check the drug safety information carefully for any food interactions.

how it affects medication absorption

Many drugs are metabolized using an enzyme called CYP3A4 in the small intestine. These fruits affect the way this enzyme works, which means you can have much more of the drug enter your bloodstream where it increases dangerous side effects. So why don't doctors simply prescribe lower amounts of the drug if you regularly eat these fruits? Well, the amount of the CYP3A4 varies from one person to the next. You may have a lot of the enzyme while someone else has very little. This means it affects people differently.

In addition to affecting the amount of drug that enters the bloodstream, these fruits can also interfere with transporters in the body that help us absorb the drugs. This results in the opposite effect, significantly less of the drug entering your body meaning you get little benefit from the drug.

problem is worse for some drugs

Certain types of medications can have more serious adverse interactions with these fruits than others. In other cases, there may not be any adverse interactions but instead zero benefit from taking the medications. For example, Fexofenadine (Allegra) is available as both prescription and OTC to relieve symptoms of seasonal allergies. Grapefruit, and sometimes orange juice and apple juice, can cause much less of the drug to enter the bloodstream. While it doesn't seem to cause any health issues, you won't see much, if any, help for your allergy symptoms.

Other drugs, such as certain statin drugs that lower cholesterol, interact in a way that allows much more of the drug to enter the body. In these cases, too much of these drugs stay int he body and increase your risk for live and muscle damage that leads to kidney failure.

A little is All it Takes

It really doesn't take much to affect your medications. You may thing that a wedge of fruit or even cup of juice would be alright, but these small amounts can have just as much effect as a larger amount. In any case, even a small change in the absorption of medication is undesirable. So if you are taking a medication that has known or suspected interactions with grapefruit or other citrus fruits, you should avoid these foods.

Can still affect drugs when not consumed together

Even if you eat these foods several hours before or several hours after you take your medication, you can still have interactions. Most drugs typically stay in the body for a long time. Still others are delayed release, which means the pills dissolve slowly over a period of several hours to even several weeks in the case of newer drugs. So don't presume that just because it's been a while since you took your medication and the risk is gone. If the label on your medicine reads "DO NOT TAKE WITH GRAPEFRUIT" or something similar, heed the warning and just avoid the foods altogether.

Ask Questions

You should always be checking the labels on your medications, as well as any safety information sheets the come with them. But it's also a good idea to ask your doctor or pharmacist about any possible interactions if you make grapefruit or other citrus fruits a regular part of your diet. These professionals are usually very up-to-date on known interactions, as well as suspected interactions. Your doctor may even be able to recommend other drugs if you can't give up certain foods or safe alternative foods.

some drugs with known interactions

  • Some statin drugs to lower cholesterol, such as Zocor (simvastatin) and Lipitor (atorvastatin)
  • Some drugs that treat high blood pressure, such as Procardia and Adalat CC (both nifedipine)
  • Some organ-transplant rejection drugs, such as Sandimmune and Neoral (both cyclosporine)
  • Some anti-anxiety drugs, such as buspirone
  • Some corticosteroids that treat Crohn's disease or ulcerative colitis, such as Entocort EC and Uceris (both budesonide)
  • Some drugs that treat abnormal heart rhythms, such as Pacerone and Nexterone (both amiodarone)
  • Some antihistamines, such as Allegra (fexofenadine)

Things to keep in mind

Scientists are currently working on breeding hybrid grapefruits that will be safe to mix with medications. Until the new fruits arrive, follow these tips:

  • Ask your pharmacist or other health care professional if there are any known interactions between your medication and any foods, particularly grapefruit and other citrus fruits.
  • Read the Medication Guide or patient information sheet that comes with your medication to see if there are known interactions with grapefruit or other citrus fruits.
  • Read the Drug Facts label on your non-prescription medicine. It should advise whether you can have grapefruit or other fruits with it.
  • If you can't have grapefruit, citrus or other fruits with your medications, pay attention to the ingredients on food labels. Some foods and beverages might be made with varying amounts of these fruits. Advise restaurants that you cannot have any of these fruits in your food.
  • Seville oranges (often used to make orange marmalade) and tangelos (a cross between tangerines and grapefruit) affect the same enzyme as grapefruit. If your medication interacts with grapefruit, you should also avoid these fruits.