3149 Phenindione Phenindione is only found in individuals that have used or taken this drug. It is an indandione that has been used as an anticoagulant. Phenindione has actions similar to warfarin, but it is now rarely employed because of its higher incidence of severe adverse effects. (From Martindale, The Extra Pharmacopoeia, 30th ed, p234). Phenindione inhibits vitamin K reductase, resulting in depletion of the reduced form of vitamin K (vitamin KH2). As vitamin K is a cofactor for the carboxylation of glutamate residues on the N-terminal regions of vitamin K-dependent proteins, this limits the gamma-carboxylation and subsequent activation of the vitamin K-dependent coagulant proteins. The synthesis of vitamin K-dependent coagulation factors II, VII, IX, and X and anticoagulant proteins C and S is inhibited. Depression of three of the four vitamin K-dependent coagulation factors (factors II, VII, and X) results in decreased prothrombin levels and a decrease in the amount of thrombin generated and bound to fibrin. This reduces the thrombogenicity of clots. 83-12-5 4760 C15H10O2 222.068080 White powder. 150°C 27 mg/L (at 20°C) Ingestion (L1817) ; dermal (L1817). Absorbed slowly from the gastrointestinal tract. Phenindione inhibits vitamin K reductase, resulting in depletion of the reduced form of vitamin K (vitamin KH2). As vitamin K is a cofactor for the carboxylation of glutamate residues on the N-terminal regions of vitamin K-dependent proteins, this limits the gamma-carboxylation and subsequent activation of the vitamin K-dependent coagulant proteins. The synthesis of vitamin K-dependent coagulation factors II, VII, IX, and X and anticoagulant proteins C and S is inhibited. Depression of three of the four vitamin K-dependent coagulation factors (factors II, VII, and X) results in decresed prothrombin levels and a decrease in the amount of thrombin generated and bound to fibrin. This reduces the thrombogenicity of clots. (A308) Hepatic. Half Life: 5-10 hours Oral, mouse: LD50 = 175 mg/kg; Oral, rat: LD50 = 163 mg/kg. No indication of carcinogenicity to humans (not listed by IARC). Phenindione is an anticoagulant drug derived from coumarin. (L1262) For the treatment of pulmonary embolism, cardiomyopathy, atrial fibrillation and flutter, cerebral embolism, mural thrombosis, and thrombophili. Also used for anticoagulant prophylaxis. Phenindione is an anticoagulant and may cause internal bleeding, leading to shock, loss of consciousness, and eventually death. (L1257) Phenindione may cause bleeding complications. (L1257) The primary antidote to phenindione poisoning is immediate administration of vitamin K1 (initially slow intravenous injections of 10-25 mg repeated all 3-6 hours until normalisation of the prothrombin time; then 10 mg orally four times daily as a "maintenance dose"). It is an extremely effective antidote, provided the poisoning is caught before too much damage has been done to the victim's circulatory system. At high doses phenindione can affect the body for many months, and the antidote must be administered regularly for a long period of time. (L1257) 2009-07-23T18:26:20Z 2026-03-26T21:06:41Z Phenindione C07584 8066 Phenindione DB00498 true O=C1C(C(=O)C2=CC=CC=C12)C1=CC=CC=C1 C15H10O2 InChI=1S/C15H10O2/c16-14-11-8-4-5-9-12(11)15(17)13(14)10-6-2-1-3-7-10/h1-9,13H NFBAXHOPROOJAW-UHFFFAOYSA-N 222.2387 222.068079564 Exogenous Solid 2.9 HMDB14641 CHEMBL711 4596 CHEM002441 DTXSID5023453 NS00003441 2-phenyl-2,3-dihydro-1H-indene-1,3-dione