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Grapefruit drug interactions linked to 85 medications, says study

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Image by The U.S. Food and Drug Administration


A growing number of prescription medications can have serious, sometimes deadly, side effects when mixed with grapefruit, according to a study published this week in the Canadian Medical Association Journal.

Medical News Today (MNT) reports that researchers found more than 85 medications that may have some type of interaction with grapefruit, and that the number of drugs that could cause a dangerous reaction when paired with grapefruit  has climbed from 17 to 43 in the past four years. 

The report also suggests that health professionals and patients are often unaware of the possible side effects.

MNT explains that furanocoumarins found in grapefruit inhibit the body's CYP3A4 metabolizing enzyme from properly breaking down medications. As a result, more of the drug winds up in the bloodstream, and toxic drug levels or overdose can occur, resulting in:

  • respiratory failure
  • gastrointestinal bleeding
  • bone marrow suppression in patients with weak immune systems
  • renal toxicity
  • acute kidney failure
  • sudden death

An FDA Consumer Update on the matter was issued in February. The Mayo Clinic says pomelos and Seville oranges — a bitter variety used to make marmalades — may also have a similar effect.

ABC News says that as little as "one grapefruit or one 8-ounce glass of grapefruit juice can cause an effect that may last more than 24 hours," and reports the following A-Z partial list of medications believed to interact with grapefruit:

Alfentanil (oral)
Amiodarone
Apixaban
Atorvastatin
Buspirone
Clopidogrel
Crizotinib
Cyclosporine
Darifenacin
Dasatinib
Dextromethorphan
Domperidone
Dronedarone
Eplerenone
Erlotinib
Erythromycin
Everolimus
Felodipine
Fentanyl (oral)
Fesoterodine
Halofantrine
Ketamine (oral)
Latatinib
Lovastatin
Lurasidone
Maraviroc
Nifedipine
Nilotinib
Oxycodone
Pazopanib
Pimozide
Primaquine
Quinine
Quetiapine
Quinidine
Rilpivirine
Rivaroxaban
Silodosin
Simvastatin
Sirolimus
Solifenacin
Sunitinib
Tacrolimus
Tamsulosin
Ticagrelor
Triazolam
Vandetanib
Venurafenib
Verapamil
Ziprasidone

The Mayo Clinic also posts a partial list organized by drug type:

Anti-anxiety Buspirone
Anti-arrhythmia Amiodarone (Cordarone)
Antidepressant Sertraline (Zoloft)
Antihistamine Fexofenadine (Allegra)
Anti-retroviral Saquinavir (Invirase), indinavir (Crixivan)
Anti-seizure Carbamazepine (Carbatrol, Tegretol)
Calcium channel blocker Nifedipine (Procardia), nimodipine (Nimotop), nisoldipine (Sular)
Immunosuppressant Cyclosporine (Neoral, Sandimmune), tacrolimus (Prograf), sirolimus (Rapamune)
Statin Simvastatin (Zocor), lovastatin (Mevacor), atorvastatin (Lipitor)

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