Grapefruit and medication interactions

Dear Jess, I love to eat grapefruit, but don’t want to risk effects on my medications.  Do I need to avoid grapefruit completely?  If I have medication first thing in the morning, can I eat grapefruit later in the morning?  Or, can I eat grapefruit in the morning and then take medication at night? Thanks for your help, Sheridan B.

Dear Sheridan, As innocuous as grapefruit juice sounds, there are, indeed, many drugs that interact with grapefruit juice. Other citrus fruits (but not all citrus fruits) including grapefruit sections, Seville oranges, pummelos and tengelos may cause similar interactions.

In a nutshell, here’s how it works: Components in grapefruit juice inhibit specific enzymes needed to metabolize the affected drug in the small intestine. Since the drug is not metabolized as much as usual prior to absorption into the bloodstream you end up with a higher than intended dose of the drug in your system. This can increase the side effects or toxicity of the drug.

The grapefruit juice’s inhibiting effect on these enzymes can persist for up to 72 hours after consumption of grapefruit.

A general rule is that if you are taking one or more medications that interacts with grapefruit juice, it is wise to heed the warnings to avoid grapefruit juice (and other citrus fruits that cause this inhibitory effect). In some cases the consequential side effects can be very serious, even fatal.

Of course, not all drugs are metabolized using the enzymes inhibited by grapefruit juice. Check with your health care professional if you are unsure. This list might be also helpul but should not be a replacement for medical consultation: http://www.globalrph.com/gfruit.htm

There are many other variables that affect metabolism of a drug including health status, age, sex, size, and other currently used medication. Therefore it is important to talk to your health care provider specifically about any concerns regarding your prescription medications.

Remember, if grapefruit is off your list because of your current medication use, there are lots of other delicious fruits with which to replace it! And berry season is just around the corner!

To your good health-
Jess

Jessica Adlin, MS, CN