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List of drugs affected by grapefruit

  Grapefruit and grapefruit juice has the potential to interaction with numerous drugs. This is due to the fruit's relatively high concentration of naringin, bergamottin, and dihydroxybergamottin, which interfere with the intestinal enzyme cytochrome P450 isoform CYP3A4. However, bioactive compounds in grapefuit juice may also interfere with p-glycoprotein and organic anion transporting polypeptides (OATPs) either increasing or decreasing bioavailability of a number of drugs.

Affected drugs

The following drugs interact with CYP3A4:

Additional drugs found to be affected by grapefruit juice include, but are not limited to:

Effects on enzymes

Grapefruit juice interacts with many oral drugs. Compounds in the juice including bergamottin, dihydroxybergamottin, and some flavonoids such as naringin effect the activity of certain intestinal enzymes including CYP3A4 and CYP1A2.

These cytochrome P450 enzymes, which metabolize many drugs, are inhibited by grapefruit juice. As a result, serum drug concentrations increase, and may become toxic. This is particularly dangerous when the drug in question has a low therapeutic index, so that a small increase in blood concentration can be the difference between therapeutic success and toxicity. Grapefruit juice only inhibits the enzyme within the intestines, not in the liver or elsewhere in the body, and does not impact injected drugs. The degree of the effect varies widely between individuals and between samples of juice, therefore it cannot be accounted for a priori.

Recently some researchers have shown that furanocoumarins, rather than flavonoids, may be the ingredients causing the various drug interactions.[6]

The flavonoid existing in highest concentration in grapefruit juice is naringin, which in humans is metabolized to naringenin. Other flavonoids exist in grapefruit juice in lower concentrations as well. Orange juice does not contain naringin in as high a concentration, instead containing hesperetin. It is sometimes recommended as a substitute. Juice of limes and Seville oranges can also inhibit drug metabolism, however, as can apple juice with some drugs.[6]

Drugs affected by grapefruit juice[6]
Drug class Major Interactions Minor interactions
Calcium channel antagonists Plendil
Cardene (Nicardipine)
Procardia (Nifedipine)
Statins (HMG-CoA reductatase inhibitors)Mevacor (Lovastatin) Lipitor
Baycol (off the market)
Immunosuppressants Sandimmune (Cyclosporine)
Sedatives, hypnotics, and anxiolyticsBuspar Halcion
Valium (Diazepam)
Sonata (Zaleplon)
Other psychotropics Tegretol (Carbamazepine)
AntihistaminesSeldane (off the market)
Hismanal (off the market)
Claritin (Loratadine)
HIV protease inhibitors Invirase
Hormones Ortho-Cept (Ethinyl estradiol)
Depo-Medrol (Methylprednisolone)
Other drugsCordarone Viagra


  1. ^ Sugimoto K, Araki N, Ohmori M, et al (2006). "Interaction between grapefruit juice and hypnotic drugs: comparison of triazolam and quazepam". Eur. J. Clin. Pharmacol. 62 (3): 209–15. doi:10.1007/s00228-005-0071-1. PMID 16416305.
  2. ^
  3. ^ a b c d e f g h Bailey DG, Dresser GK (2004). "Interactions between grapefruit juice and cardiovascular drugs". American journal of cardiovascular drugs : drugs, devices, and other interventions 4 (5): 281–97. PMID 15449971.
  4. ^ Jetter A, Kinzig-Schippers M, Walchner-Bonjean M, et al (2002). "Effects of grapefruit juice on the pharmacokinetics of sildenafil". Clin. Pharmacol. Ther. 71 (1): 21–9. doi:10.1067/mcp.2002.121236. PMID 11823754.
  5. ^ H. Hori, R. Yoshimura, N. Ueda, S. Eto, K. Shinkai, S. Sakata, O. Ohmori, T. Terao and J. Nakamura (2004). "Fluvoxamine, In Vivo Study". J Clin Psychopharmacol 23 (4): 422-424.
  6. ^ a b c Bakalar, Nicholas. "Experts Reveal the Secret Powers of Grapefruit Juice", The New York Times, 2006-03-21, p. F6. Retrieved on 2006-11-21. (English) 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "List_of_drugs_affected_by_grapefruit". A list of authors is available in Wikipedia.
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