[Interactions between food and drugs. 2. Disturbances of drug metabolism and synergistic mode of action].

The paper overviews food-drug interactions. The part 2 reviews the interactions of foods with the drugs which occur at the level of metabolism. Concomitant intake with food increases or decreases the concentrations of many agents in humans. The effect seems to be mediated mainly by suppression of the cytochrome P450 in the liver and in the small intestine wall. This results in a diminished first pass metabolism with higher bioavailability and increased maximal concentrations of substrates of this enzyme. To avoid the interactions many drugs should not be taken with the meal and citrus juices, particularly grapefruit juice.