Answers About Grapefruit and Drug Interactions

 

 

by Dr. Stephen Sinatra 
Filed Under: General Health, Q&As, Heart Health 

QUESTION: HOW DOES GRAPEFRUIT JUICE AND MEDICATION INTERACT?

The grapefruit juice and drug interactions arise because grapefruit contains a compound called bergamottin, which blocks the action of an enzyme in the liver. (Cytochrome P450 3A4, in case you’re interested.) This enzyme is also involved in the metabolism of more than 30 different medications.

When this enzyme is blocked, your body can’t clear out the drug as it should, which means the drug can build up to dangerous levels.

More than 50 medications are subject to a possible grapefruit juice and drug interaction. Drugs for blood pressure, blood clotting and cholesterol control are among them. Here’s a list of drugs that interact with grapefruit juice.

 

QUESTION: I KNOW THAT MANY CARDIOVASCULAR DRUGS INTERACT WITH GRAPEFRUIT. MY QUESTION IS WHETHER THE “GRAPEFRUIT EFFECT” IS LIMITED TO GRAPEFRUIT. WHAT ABOUT OTHER CITRUS FRUITS, LIKE ORANGES?

Other related citrus fruits may cause reactions similar to the grapefruit and drug interactions, depending on how much bergamottin they contain. Seville oranges contain a significant amount of bergamottin. They’re used to make marmalade and compote (but not orange juice) and their bergamot oil is used as the distinctive flavoring in Earl Grey and Lady Grey teas. Pummelos/pomelos have also been implicated in grapefruit and drug interactions.

Certainly there are other foods that can affect medications you’re taking, but grapefruit and grapefruit juice are the biggest culprits in drug interactions.

 

QUESTION: I REGULARLY EAT GRAPEFRUIT EVEN THOUGH MY MEDICATION IS ON YOUR LIST OF DRUGS THAT GRAPEFRUIT INTERACTS WITH. WHAT SHOULD I DO? SHOULD I STOP?

If you’re already consuming grapefruit or grapefruit juice consistently, and you’re at a stable dose on your medication, then you should not stop consuming it.

Your doctor has calculated your medication dose based on your individual body and habits—including what you eat and drink. If your consumption of grapefruit has already been taken into account, then stopping suddenly could cause levels of your medication to fall too low, with possible negative effects.

 

 

 

 

Grapefruit Juice and Medication Interaction

by Dr. Stephen Sinatra 
Filed Under: General Health 

Grapefruit and its juice can create medication interactions with many types of drugs, from antibiotics to antipsychotics.

These drugs should never be combined with grapefruit. Also, as a general rule, always remember to ask about any possible medication interactions with other drugs or foods whenever your doctor prescribes you a new medication.

 

Avoid Medication Interaction With Grapefruit

Aldosterone inhibitors:
eplerenone (Inspra)

 

Anti-arrhythmics: 
amiodarone (Cordarone) 
quinidine (Quinaglute, Quinidex, Quinora)

 

Antihypertensives: 
carvedilol (Coreg) 
losartan (Cozaar)

 

Blood thinners:
warfarin (Coumadin)

 

Calcium channel blockers: 
felodipine (Plendil) 
nicardipine (Cardene) 
nifedipine (Adalat, Procardia) 
nimodipine (Nimotop) 
isradipine (DynaCirc) 
verapamil (Isoptin, Verelan, Calan, Bosoptin, Covera-HS)

 

Statin drugs: 
atorvastatin (Lipitor) 
lovastatin (Mevacor) 
simvastatin (Zocor, Vytorin)

 

Anticonvulsants:
carbamazepine (Tegretol

 

Antidepressants: 
sertraline (Zoloft) 
trazodone (Desyrel) 
nefazodone (Serzone)
clomipramine (Anafranil)

 

Antihistamines: 
fexofenadine (Allegra)

 

Anti-anxiety drugs: 
diazepam (Valium) 
midazolam (Versed) 
triazolam (Halcion) 
buspirone (BuSpar)

 

Corticosteroids: 
methylprednisolone, oral (Medrol) 
budesonide (Pulmicort, Rhinocort)

 

Immunosuppressants: 
cyclosporine (Sandimmune, Neoral) 
tacrolimus (Prograf)

 

Protease inhibitors: 
ritonavir (Norvir) 
nelfinavir (Viracept) 
saquinavir (Invirase, Fortovase)

 

 

 

DISCLAIMER: The content of DrSinatra.com is offered on an informational basis only, and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified health provider before making any adjustment to a medication or treatment you are currently using, and/or starting any new medication or treatment. All recommendations are “generally informational” and not specifically applicable to any individual’s medical problems, concerns and/or needs.