Due to its narrow therapeutic index, the fact that it can only be eliminated from the body after inactivation by the liver enzymes CYP2C9 and CYP3A4, and its high plasma protein binding (see below),<unk>  has significant interactions with a large number of other drugs and with some kinds of food. Some examples are: * CYP2C9 inducers decrease its concentrations and therefore its anticoagulant effect: rifampicin, St John's wort. * CYP3A4 inducers also decrease its anticoagulant effect: also rifampicin and St John's wort. * CYP2C9 inhibitors increase its concentrations and therefore the risk for bleeding: amiodarone. * CYP3A4 inhibitors also increase the risk for bleeding: clarithromycin, ketoconazole, grapefruit juice, also amiodarone. * Substances that displace<unk>  from its plasma protein binding increase its free blood concentrations and therefore increase the risk for bleeding: a number of nonsteroidal anti-inflammatory drugs (NSAIDs), especially aspirin. * Antibiotics increase the risk for bleeding, probably because they kill vitamin K producing bacteria of the gut flora: possibly all antibiotics; documented for amoxicillin and quinolone antibiotics among others. * Food containing vitamin K, such as cabbage, spinach and broccoli, might reduce the drug's effectivity. High doses of vitamin K antagonise<unk>  20 to 24 hours after ingestion or infusion; the effect lasts for 7 to 10 days.
Phenprocoumon
Warfarin
Prasugrel
Elinogrel
Palladin
Dabigatran
Apixaban
Alteplase