Factors affecting the effectiveness of warfarin The following factors may affect the anticoagulant effect of warfarin while taking warfarin: (1) Drug interactions. Certain drugs may affect the anticoagulant effect when combined with warfarin. Those that enhance the anticoagulant effect include: broad-spectrum antibiotics, metronidazole, aspirin, fenbendazole, alcohol, and anti-inflammatory pain; those that reduce the anticoagulant effect include: vitamin K1, spironolactone, and rifampin. Some Chinese medicines can affect the anticoagulation effect, please consult your doctor in detail before using Chinese herbs or proprietary Chinese medicines. Liu Xiaojun, Department of Cardiothoracic Surgery, Fu Wai Hospital, Qingdao (2), Some foods rich in vitamin K may reduce the effectiveness of anticoagulant drugs, such as animal liver. The following is the amount of vitamin K per 100 grams of dry food (milligrams): spinach (4.40), cabbage (3.20), cauliflower (3.00), peas (2.80), carrots (0.80), tomatoes (0.40C0.80), potatoes (0.16), pig’s liver (0.80), eggs (0.80), cow’s milk (trace). Of course, anticoagulation may only be affected by eating large amounts of a particular food group. With so many drug effects, and so many foods with vitamin K content, do I need to memorize them all? There is no need to memorize all of this, just some of it. Patients need to remember is the following three situations must be diligently check anticoagulation! A, change in medication habits: such as new drugs or the original drug dose adjustment (intravenous or oral drugs need to pay attention to). B. Dietary habits have changed: for example, the patient moved from the inland area to the coastal area for a long time, and the diet structure has changed from beef and mutton to seafood. C, anticoagulation results in the original stable situation suddenly appeared large changes: for example, the original anticoagulation has been stable, suddenly an anticoagulation results increased, INR more than 3.0, in order to prevent the wrong results due to test error, it is recommended that the same day to immediately stop, and again review the anticoagulation. (3) Adverse lifestyle habits and changes in physical condition: fever, diarrhea, vomiting affects drug absorption, liver and kidney disease affects the synthesis and metabolism of vitamin K, which in turn affects anticoagulation, and short-term changes in body weight.