You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is All about warfarin are true EXCEPT: and explain in detail?
Contraindicated in hepatic failure REF: Goodman and Gillman's 11th edition, page 955-956 Warfarin: Therapeutic doses of warfarin decrease by 30-50% the total amount of each vitamin K-dependent coagulation factor made by the liver The usual adult dose of warfarin (COUMADIN) is 5 mg/day for 2-4 days, followed by 2-10 mg/day as indicated by measurements of the INR The bioavailability of warfarin is nearly complete when the drug is administered orally, intravenously, or rectally. Warfarin is almost completely (99%) bound to plasma proteins, principally albumin, and the drug distributes rapidly into a volume equivalent to the albumin space The t1/2 ranges from 25 to 60 hours (means 40 hours); the duration of action of warfarin is 2-5 days. Bleeding is the major toxicity of oral anticoagulant drugs. Crosses placenta and causes fetal malformations and aboion if given during pregnancy (see APPENDIX-32)