1, drugs Coumarin anticoagulants are susceptible to the influence of other drugs, some enhanced, some weakened, or even offset the anticoagulant effect.A Enhance the effect of warfarin drugs: alcohol, cimetidine, steroids, fenbendazole, anti-inflammatory pain, quinidine, salicylate, mirex, sulfa, pau tazone, high-dose gentamicin, thyroxine, chloral hydrate, etc. B weaken the effect of warfarin drugs: vitamin K, sleeping pills, estrogen, oral contraceptives, rifampin, cholestyramine, and barbiturates. The above drugs should be used with caution or taken under medical supervision and monitoring. If there is a significant interference effect should be avoided, such as vitamin K, etc.; some of them can be used as alternative drugs, such as using Valium instead of other sleeping pills. If you have to use, you should check the prothrombin time and activity to adjust the amount of anticoagulant as appropriate. Long-term use of female contraceptives, can be in the beginning of drug testing PT, in order to decide whether to increase the dose of anticoagulants. If a short-term increase of a certain drug, such as cold medicine, temporary injection of antibiotics for a few days, etc., it is not necessary to adjust the medication, and usually does not interfere greatly. In addition, there are many Chinese medicines and pCms that may have a great effect on anticoagulants. 2, food Postoperative diet can also interfere with the anticoagulant effect of coumarin drugs, but the general interference is very small. Vitamin K content per 100g of dry food (mg): spinach (4.40), cabbage (3.20), cauliflower (3.00), peas (2.80), carrots (0.80), tomatoes (0.40 – 0.80), potatoes (0.16), pig liver (0.80), eggs (0.80), cow’s milk (trace). Some foods such as spinach, brussels sprouts, alfalfa, tomatoes, cabbage, cauliflower, fresh peas, and pig’s liver, because these foods contain high levels of vitamin K. Eating too much of them in too large a quantity or for too long a period of time reduces the effect of anticoagulant medications and shortens the PT value. When consumed in large quantities for a long period of time, the prothrombinogen time should be checked in time to adjust the anticoagulant dose. In general, after warfarin is adjusted and stabilized, the anticoagulant effects of a normal diet are not important. After you resume normal diet and living habits, you should pay attention to the following points: (1) after discharge, generally do not restrict the diet, you can improve the meals, change the variety of food, but do not monotonous long-term to eat a certain kind of vegetables containing high amount of vitamin K, of course, do not have to change the habit of eating a certain amount of vegetables. (2) In a certain short period of time when eating vegetables with high vitamin K content and the amount of diet increases or decreases significantly, the PT should be reviewed and adjusted according to the results. (3) Alcohol consumption can affect the metabolism of warfarin, so during the anticoagulation period, one should try not to drink alcohol, not to mention alcoholism. (3) Disease: Steatorrhea, biliary obstruction, starvation, acute viral hepatitis, hyperthyroidism, post-surgical infections, hyperthermia and other diseases can reduce the absorption of vitamin K, and the anticoagulant effect of Warfarin is enhanced. In congestive heart failure, hepatomegaly, poor liver function or ascites, the sensitivity to anticoagulants is enhanced due to impaired hepatic production of coagulation factors. Patients with myocardial infarction and pulmonary embolism have a low tolerance for oral anticoagulation, and PT is quickly prolonged. Others, such as older women, or patients in poor general condition, have increased sensitivity to these drugs. In addition, Warfarin tablets such as moisture, deterioration, mold and other reasons such as their own vomiting, diarrhea and other factors can affect the anticoagulant effect of Warfarin. Therefore, attention should be paid to review the PT and adjust the dose of anticoagulant. 4.Adjustment period of anticoagulant drugs Adjustment of oral anticoagulant dosage is important to start in the early postoperative period. Within 1~2 weeks of anticoagulation, the effect of anticoagulant drugs is often unstable, manifested by large fluctuations in PT. The reason for this may be related to the complexity of medication in the early postoperative period, poor absorption in the gastrointestinal tract, liver function and dietary conditions and other influences. In the late postoperative period, it is often necessary to increase the dosage of drugs after the systemic condition improves and liver function returns to normal.