CAM InteractionsDiet-Nutrition

Update: Grapefruit juice:Rx drug interactions

According to Dr. William McCloskey, the likelihood of drug:grapefruit juice interactions having a negative effect on a patient’s response to the drug has not been clearly established.

This might be due to the fact that many drugs affected by grapefruit juice have a wide therapeutic index. In other words, toxic blood levels are so much higher than the blood levels needed to achieve an effective treatment dose that any increase caused by grapefruit juice is not sufficient to reach toxicity.

That’s not to say there is no risk of a grapefruit juice:drug interaction.

Unfortunately, the source article has been deleted, but here’s the bottom line. If you take any of the drugs listed below and feel you must drink grapefruit juice, first discuss it with your doctor.

  • Amiodarone (Cordarone)
  • Atorvastatin (Lipitor)
  • Buspirone (Buspar)
  • Carbamazepine (Tegretol)
  • Clomipramine (Anafranil)
  • Cyclosporine (Sandimmune, Neoral)
  • Diazepam (Valium)
  • Etoposide (VePesid)
  • Felodipine (Plendil)
  • Fexofenadine (Allegra)
  • Itraconazole (Sporanox)
  • Lovastatin (Mevacor)
  • Methadone (Methadose)
  • Midazolam (Versed)
  • Nicardipine (Cardene)
  • Nifedipine (Procardia)
  • Nimodipine (Nimotop)
  • Nisoldipine (Sular)
  • Saquinavir (Invirase)
  • Sildenafil (Viagra)
  • Simvastatin (Zocor)
  • Triazolam (Halcion)

3/19/08 11:13 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.