Grapefruit and Drug Interactions
Betty Chaffee, PharmD, is owner and sole proprietor of BetterMyMeds, a Medication Management service devoted to helping people get the maximum benefit from their medications.
Are you one of the many people who count grapefruit as one of your favorite fruits or juices? If so, you may have been disappointed if you were told to avoid it because of a medication. It's even worse if you learn you'll need to take that medication for the rest of your life. Avoiding one of your favorite fruits forever is a big ask.
I was prompted to write about this topic by an attendee at a talk I gave recently (thank you!). Not being a fan of grapefruit myself, it never occurred to me how big a deal it might be for those who really enjoy it. So let's talk about how grapefruit causes problems with some medicines, and what you can do about it.
A little background
Most medications are metabolized in the body by proteins called enzymes. I've written in the past about how our genetic makeup affects the way drug-metabolizing enzymes work. But other things can also affect these enzymes. Some medications, for example, can speed up or slow down enzyme activity. And, it turns out, so can some foods.
The dangers of grapefruit
Grapefruit can slow the activity of a particular enzyme known as CYP3A4. CYP3A4 is responsible for the metabolism of lots of medications. It turns some into active medications after we take them, and when that process is slowed the drug may never have its intended effect. In other cases, CYP3A4 inactivates drugs so they can be eliminated -- here, if it's slowed the drug stays active too long and can cause side effects. For many medications, this interaction can result in serious health consequences.
The list of medications that can be affected by grapefruit is long. You can find many examples here. If you're not sure whether one of your medications is affected, go to drugs.com and type in its name. Click on "drug interactions" and scroll down until you see "food interactions". If there's an interaction with grapefruit, you'll find it there.
What alternatives are there?
Unfortunately, grapefruit has a major interaction with some medications. If you're on one of those drugs, it's just too risky to eat or drink grapefruit at all. So you're not doing yourself a favor if you simply choose to enjoy grapefruit regardless of the recommendations. That would put you at risk for adverse effects from the interacting medication. And choosing to stop taking your medication so you can enjoy grapefruit may also put your health at risk. But there may be a couple of safer alternatives.
Learn more about the interaction
While some of the interactions between medications and grapefruit can cause major problems, others aren't quite so dangerous. These more mild or moderate interactions may not be as much cause for concern. So if you're taking a drug in this category, it's possible that you can still enjoy grapefruit or grapefruit juice in limited quantities. If you've been told to avoid grapefruit, go to drugs.com as suggested above and take a look. It's possible you'll find out that the interaction is less concerning, and that a limited amount of grapefruit may still be safe.
Ask about alternative drugs
Another possible alternative is to ask about using a different medication. Your pharmacist can help with this. Medications that belong to the same drug class are often chemically distinct. They may have the same effect on disease but be different in other ways. If you're taking a drug that interacts with grapefruit, maybe there's a different drug in the same class that would work for you AND allow you to enjoy grapefruit. For example, the "statin" class of cholesterol drugs includes simvastatin, pravastatin, and atorvastatin, among others. Grapefruit should be completely avoided with simvastatin. But it can be enjoyed in limited amounts with atorvastatin, while there's no interaction at all with pravastatin. You, your pharmacist, and your doctor can talk about whether an alternative drug should be tried.
Communication with your doctor is key
Your doctor can't know what's important to you unless you tell them. As I said in my last post, good communication with your doctor improves your chances of staying healthy. If you're a big fan of grapefruit and your doctor prescribed a medication that keeps you from enjoying it, be open about your concerns. It'll be important for you to clearly understand the benefits of the medication on your health, and for you to explain the impact on your well-being. Then you, your doctor and your pharmacist can work together to see if there are any alternatives for you.
And as always, we love to hear from you! You can post a comment or a question below, or contact us directly at BetterMyMeds!