Grapefruit
Drug interactions
This happens in two very different ways. In the first, the effect is from bergamottin, a natural furanocoumarin in both grapefruit flesh and peel that inhibits the CYP3A4 enzyme, (among others from the P450 enzyme family responsible for metabolizing 90% of drugs). The action of the CYP3A4 enzyme itself is to metabolize many medications. If the drug's breakdown for removal is lessened, then the level of the drug in the blood may become too high or stay too long, leading to adverse effects. On the other hand, some drugs must be broken down to become active, and inhibiting CYP3A4 may lead to reduced drug effects.
Grapefruit-16