Food-drug interaction: Grapefruit juice augments drug bioavailability - Mechnism, extent and relevance

A. Dahan, H. Altman

Research output: Contribution to journalReview articlepeer-review

212 Scopus citations


More than a decade has passed since it was unintentionally discovered that grapefruit juice interacts with certain drugs. The coadministration of these drugs with grapefruit juice can markedly elevate drug bioavailability, and can alter pharmacokinetic and pharmacodynamic parameters of the drug. The predominant mechanism for this interaction is the inhibition of cytochrome P-450 3A4 in the small intestine, resulting in a significant reduction of drug presystemic metabolism. An additional mechanism is, presumably, the inhibition of P-glycoprotein, a transporter that carries drug from the enterocyte back to the gut lumen, resulting in a further increase in the fraction of drug absorbed. Some calcium channel antagonists, benzodiazepines, HMG-CoA reductase inhibitors and cyclosporine are the most affected drugs. A single exposure to one glass of the juice can usually produce the maximal magnitude of the interaction. The data available so far, concerning this interaction and its clinical implications, are reviewed in this article. It is likely that more information regarding this interaction will accumulate in the future, and awareness of such is necessary for achieving optimal drug therapy.

Original languageEnglish
Pages (from-to)1-9
Number of pages9
JournalEuropean Journal of Clinical Nutrition
Issue number1
StatePublished - 1 Jan 2004
Externally publishedYes


  • Bioavailability
  • Cytochrome P-450 3A4
  • Drug interaction
  • Grapefruit
  • P-glycoprotein
  • Pharmacokinetics

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Nutrition and Dietetics


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