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Update on Grapefruit Juice-Drug Interactions

Worst Pills, Best Pills Newsletter article July, 2012

In February 2012, the Food and Drug Administration (FDA) updated its information about grapefruit juice-drug interactions, including a notice found in new research that grapefruit juice decreases the effectiveness of some drugs. Public Citizen warned readers about the potentially dangerous interactions between grapefruit juice and some prescription and over-the-counter drugs in the February 2004 issue of Worst Pills, Best Pills News. We also warned readers that grapefruit juice-drug...

In February 2012, the Food and Drug Administration (FDA) updated its information about grapefruit juice-drug interactions, including a notice found in new research that grapefruit juice decreases the effectiveness of some drugs. Public Citizen warned readers about the potentially dangerous interactions between grapefruit juice and some prescription and over-the-counter drugs in the February 2004 issue of Worst Pills, Best Pills News. We also warned readers that grapefruit juice-drug interactions cannot be fully avoided by drinking grapefruit juice at a time other than when a medication is taken. The table below lists a total of 82 drugs that can interact with grapefruit juice, resulting in drug levels that are either too high or too low.

Grapefruit juice’s ability to cause potentially toxic blood levels of certain drugs has been known for several decades. Most drug interactions with grapefruit juice result in an increased amount of a certain drug being absorbed into the bloodstream, leading to a higher concentration of the drug in the body and possibly to more adverse drug reactions because of these higher drug levels.

Table 1. Some Drugs That Interact With Grapefruit Juice

Generic Name Brand Name
albendazole ALBENZA
aliskiren TEKTURNA
alprazolam† XANAX
amiodarone**** CORDARONE, NEXTERONE
amlodipine** NORVASC
amprenavir AGENERASE
artemether COARTEM
atorvastatin LIPITOR
budesonide ENTOCORT EC
buspirone** BUSPAR
carbamazepine TEGRETOL
cetirizine** ZYRTEC
chlordiazepoxide and clidinium* LIBRAX
cisapride PROPULSID
citalopram** CELEXA
clarithromycin** BIAXIN
clonazepam KLONOPIN
clozapine** CLOZARIL
cyclosporine NEORAL, SANDIMMUNE
darifenacin ENABLEX
dasatinib SPRYCEL
diazepam* VALIUM
diltiazem** CARDIZEM CD, DILACOR XR, TIAZAC
diphenhydramine BENADRYL
dronedarone* MULTAQ
erlotinib TARCEVA
erythromycin E-MYCIN, EES, ERYTHROCIN
estradiol [patch]** CLIMARA
ethinyl estradiol with norethindrone FEMHRT

 

Generic Name Brand Name
etoposide VEPESID
felodipine PLENDIL
fexofenadine** ALLEGRA
fluoxetine** PROZAC, SARAFEM
fluvastatin LESCOL, LESCOL XL
fluvoxamine** LUVOX
haloperidol** HALDOL
imatinib GLEEVEC
indinavir CRIXIVAN
isradipine** DYNACIRC, DYNACIRC CR
itraconazole* SPORANOX
lapatinib TYKERB, TYVERB
loratadine** CLARITIN
lorazepam* ATIVAN
lovastatin MEVACOR
methylprednisolone MEDROL
midazolam VERSED
nicardipine** CARDENE, CARDENE SR
nefazodone* SERZONE
nelfinavir VIRACEPT
nifedipine** ADALAT CC, PROCARDIA XL, AFEDITAB, NIFEDIAC
nilotinib TASIGNA
nimodipine NIMOTOP
nisoldipine SULAR
omeprazole** PRILOSEC
oxazepam** SERAX
paroxetine** PAXIL, PEXEVA
pimozide ORAP
pravastatin PRAVACHOL
praziquantel BILTRICIDE
prednisolone PRELONE

 

Generic Name Brand Name
prednisone DELTASONE
propafenone RYTHMOL
quetiapine** SEROQUEL
quinidine** DURAQUIN, QUINAGLUTE DURA-TABS, QUINIDEX
ranolazine RANEXA
ritonavir NORVIR
saquinavir INVIRASE; FORTOVASE
sertraline** ZOLOFT
sildenafil** VIAGRA
simvastatin ZOCOR
sirolimus RAPAMUNE
sunitib SUTENT
tacrolimus PROGRAF, PROTOPIC
tadalafil** CIALIS
temazepam RESTORIL
temsirolimus TORISEL
theophylline** BRONKODYL, CONSTANT-T, ELIXOPHYLLIN, QUIBRON-T-SR, SLO-BID, SLO-PHYLLIN, SOMOPHYLLIN-CRT, SOMOPHYLLIN-T, SUSTAIRE, THEO-24, THEO-DUR, THEOLAIR, THEOLAIR-SR, UNIPHYL
triazolam* HALCION
vardenafil** LEVITRA
verapamil CALAN, CALAN SR
warfarin COUMADIN
zaleplon SONATA

* Do Not Use
** Limited Use (offers limited benefits or benefits certain people or conditions)
**** Last-Choice Drug
† Do Not Use Except for Panic Disorder

However, recent research has found that grapefruit juice can also have the opposite effect and can decrease the effectiveness of other drugs. Grapefruit juice does this by blocking natural proteins, called transporters, that are needed for some drugs to be absorbed, resulting in less of these drugs getting into the bloodstream and the body. (Table 1— based in part on an extensive 2010 review that included drugs using the criteria that the medication’s U.S. or U.K. label contained a warning about grapefruit juice — lists some specific drugs that are known to interact with grapefruit juice.)

In its update, the FDA used the popular allergy and hay fever drug fexofenadine (ALLEGRA) as an example of a drug whose effect can be decreased by grapefruit juice. Fexofenadine may also be less effective if taken with orange or apple juice. The drug’s label states, “[D]o not take with fruit juices.”

Other citrus fruits, such as Seville oranges and tangelos, can also result in fruit-drug interactions. If a medication adversely interacts with grapefruit juice, these fruits should also be avoided.

 

How do I know if my drug interacts with grapefruit juice?

The best way to find out if your drug interacts with grapefruit juice is to check the drug’s Food and Drug Administration (FDA)-approved product label. You can ask your pharmacist for a product label.

If you have access to the Internet, you can check product labels at the U.S. National Library of Medicine’s DailyMed website at dailymed.nlm.nih.gov/dailymed/about.cfm. DailyMed currently lists product labels for almost 35,000 drugs. The website features the most recent product labels submitted to the FDA.

A hint for finding information about grapefruit juice interactions: After accessing the DailyMed website, enter the brand or generic name of the drug you are taking. A list of product labels will appear. Click on the drug you are taking to open the label. Once the label appears on the screen, type in “Ctrl + F” on your key board. Enter “grapefruit juice” into the find function of your Web browser. The term “grapefruit juice” will be highlighted in the document if it is discussed in your drug’s product label.

What You Can Do
You should ask your doctor or pharmacist if any of the drugs you are taking interact with grapefruit juice. Also, if you are taking one of the drugs listed in Table 1 and regularly consume grapefruit juice, tell your doctor.

Check your drug’s product label for listed interactions with grapefruit juice.

 

The FDA consumer update about grapefruit juice interactions can be read in its entirety at www.fda.gov/ForConsumers/ConsumerUpdates/ucm292276.htm.