Tuesday, October 16, 2012

What's up with grapefruit juice?

Hi all! I know it's been a little while. I have been so busy lately I feel as though my head is spinning!

I get asked often about drug interactions, as a lot of patients are on more than 2 medications. One of the most interesting interactions is grapefruit juice! This is not only an often-asked interaction on our medical boards, but also a very important interaction for my patients to be aware of! Let's get to some details...

So, to begin, we will start with the basics. Medications are either metabolized in the liver, kidneys (these two, mostly) or in the intestines. Grapefruit juice may interact with the metabolism of some medications because it inhibits an enzyme (CYP3A4) in the intestines that helps to metabolize medications. Since the enzyme that degrades the medications is inhibited (or stopped) by the juice, the other medications that you are taking may be MORE powerful, because they are not being metabolized....got that?

So, does the grapefruit juice interact with all medications? Nope. But there are quite a few...here are some of importance, that are somewhat common:

-Xanax
-Valium
-Zoloft
-Statins (for cholesterol)...in particular Lipitor and Zocor. Some other statins are NOT affected
-Losartan, Nicardipine, Nifedipine, Verapamil (these are blood pressure/heart medications)
-Synthroid (for thyroid)
-Ambien (for sleep)

There are a whole bunch more...these effects could potentially be life-threatening...so PLEASE do not take any drug interactions lightly!

....and...just to use this post as a platform, please review ANY and ALL herbal supplements that you are taking with your physician. Some are known to have some very strange side effects and a lot may interact with your other medications!

Till next time!

xo,