Interaction of grapefruit juice and calcium channel blockers

Am J Hypertens. 2006 Jul;19(7):768-73. doi: 10.1016/j.amjhyper.2005.11.003.


Drug-drug interactions are commonly recognized occurrences in the hypertensive population. Drug-nutrient interactions, however, are less well appreciated. The grapefruit juice-calcium channel blocker interaction is one that has been known since 1989. The basis for this interaction has been diligently explored and appears to relate to both flavanoid and nonflavanoid components of grapefruit juice interfering with enterocyte CYP3A4 activity. In the process, presystemic clearance of susceptible drugs decreases and bioavailability increases. A number of calcium channel blockers are prone to this interaction, with the most prominent interaction occurring with felodipine. The calcium channel blocker and grapefruit juice interaction should be incorporated into the knowledge base of rational therapeutics for the prescribing physician.

Publication types

  • Review

MeSH terms

  • Beverages / adverse effects*
  • Biological Availability
  • Calcium Channel Blockers / pharmacokinetics*
  • Calcium Channel Blockers / therapeutic use
  • Citrus paradisi / adverse effects*
  • Cytochrome P-450 CYP3A Inhibitors
  • Food-Drug Interactions*
  • Humans
  • Hypertension / drug therapy*
  • Intestines / enzymology


  • Calcium Channel Blockers
  • Cytochrome P-450 CYP3A Inhibitors