What are the precautions for oral warfarin anticoagulation therapy: 1, oral warfarin is slow to take effect, it takes about 4 days for the drug concentration in the body to reach the anticoagulant effect, the half-life is long, after discontinuation, the effect disappears in 3 to 4 days. 2, during the drug, need to draw blood to check PT (prothrombin time), by adjusting the dose of warfarin to adjust the PT-INR (International Normalized Ratio) to between 1.6 – 2.5, not more than 3.0. 3, at the beginning of taking, to 4-5 days to check the INR, after reaching therapeutic concentration, nearly a month, once a week to check the INR, stable after at least Check INR at least once a month after stabilization. 4.If bleeding occurs, such as: gum bleeding, nosebleed, hemoptysis, vomiting blood, blood in stool, black stool, etc., go to hospital immediately and check INR. 5.Caution should be paid to combined medications: aspirin, pautazone, mefenamic acid, clobetil, sulfonamide antibacterial, propoxur; chloramphenicol, allopurinol, monoamine oxidase inhibitor, metronidazole, cimetidine; azithromycin, erythromycin, clarithromycin, doxycycline, cephalosporin antibiotics, nalidixic acid, ciprofloxacin, norfloxacin, ofloxacin, liquid paraffin; quinidine, levothyroxine, phenylephrine; salicylates, acetaminophen, chlorpromazine, diphenhydramine; streptokinase, urokinase, heparin. Can act synergistically to enhance the efficacy of warfarin and can easily cause bleeding. Acidophilus, laxative, ashwagandha; antipyrine, carbamazepine, barbiturate, pentobarbital, phenobarbital, isobarbital, rifampin, vitamin K; oral contraceptives, estrogen; vitamin C, corticosteroids, phenytoin sodium, ativan, hypnotics, digitalis, epinephrine, atropine, acetylcholine. Can reduce the effectiveness of warfarin and cause thrombosis. When the above drugs are combined with warfarin, monitoring of prothrombin time (INR) should be strengthened. 6, diet must pay attention to: herbs including salvia, angelica, chrysanthemum, garlic, ginkgo, ginger, ginseng, licorice, alfalfa, fennel celery, dry celery, mother chrysanthemum. The combination of papaya, celery, and carrots in foods with warfarin can increase the risk of bleeding. Many green vegetables, including spinach, asparagus, and cauliflower, can diminish the efficacy of warfarin. In order to maintain a stable anticoagulant effect of warfarin, it is recommended that you maintain a relatively balanced diet and do not switch the type and amount of vegetables while taking the medication.