Organic derivatives of furanocoumarin interfere with liver and intestinal enzyme CYP3A4 and may be responsible for the effects of<unk>  on the enzyme. Cytochrome isoforms affected by<unk>  components also include CYP1A2, CYP2C9, and CYP2D6.<unk> s metabolized by these enzymes may have<unk>  with citrus chemicals. When<unk> s are taken orally, they enter the gut lumen to be absorbed in the small intestine and sometimes, in the stomach. In order for<unk> s to be absorbed, they must pass through the epithelial cells that line the lumen wall before they can enter the hepatic portal circulation to be distributed systemically in blood circulation.<unk> s are metabolized by<unk> -specific metabolizing enzymes in the epithelial cells. Metabolizing enzymes transform these<unk> s into metabolites. The primary purpose for<unk>  metabolism is to detoxify, inactivate, solubilize and eliminate these<unk> s. As a result, the amount of the<unk>  in its original form that reaches systemic circulation is reduced due to this first-pass metabolism. Many<unk> s are impacted by consumption of citrus juice. When the metabolizing enzyme is inhibited, less of the<unk>  will be metabolized by it in the epithelial cells. This<unk> is particularly dangerous when the<unk>  in question has a low therapeutic index, so that a small increase in blood concentration can be the difference between therapeutic effect and toxicity. Citrus juice inhibits the enzyme only within the intestines if consumed in small amounts. When larger amounts are consumed they may also inhibit the enzyme in the liver. The hepatic enzyme inhibition may cause an additional increase in potency and a prolonged metabolic half-life (prolonged metabolic half-life for all ways of<unk>  administration). The degree of the effect varies widely between individuals and between samples of juice, and therefore cannot be accounted for a priori. Another mechanism of<unk> is possibly through the multidrug resistance-associated protein 2 localized in the brush border of the enterocytes.
Grapefruit–drug interactions
Pesticide poisoning
Allergic shiner
NSAID hypersensitivity reactions
Amnesic shellfish poisoning
Non-freezing cold injury
Chinese alchemical elixir poisoning
Paralytic shellfish poisoning