Drug interactions

Grapefruit can have anumber of interactionswithdrugs, often increasing the effective potency of compounds. Researchers have identified 85 drugs with which grapefruit is known to have an adverse reaction.Grapefruit contains a number ofpolyphenolic compounds, including theflavanonenaringin, alongside the twofuranocoumarinsbergamottinanddihydroxybergamottin. These inhibit the drugmetabolizing enzymeisoformCYP3A4predominantly in the small intestine, but at higher doses also inhibit hepatic CYP3A4.It is via inhibition of this enzyme that grapefruit increases the effects ofa variety of drugsby increasing their bioavailability