Department of Cardiology and Surgery, The First Affiliated Hospital of Zhengzhou University
Warfarin usage after valve replacement
1. What are the effects and side effects of warfarin?
Warfarin is an anticoagulant drug that prevents thrombosis and must be taken after valve replacement. An overdose of warfarin can cause bleeding and a low dose can lead to clots, both of which are life-threatening, so be sure to adjust the dose to the required range.
2. How long should I take it?
After mechanical valve replacement, take it for life. After biological valve replacement, take it for six months if there is no atrial fibrillation, and take it for life if there is combined atrial fibrillation.
3. What is the dosage?
Once a day, with regular dose adjustment.
4. Dosage adjustment method
There are two reference indicators.
(1) PT (prothrombin time): the PT measurement value should be maintained between 18-24 seconds.
If the measured value is less than 18 seconds, increase the dose of medication.
If the measured value is less than 18 seconds, increase the dose of medication; if the measured value is more than 24 seconds, decrease the dose of medication.
(2) PT-INR International Normalized Ratio (INR): The measured value should be maintained between 1.5 and 2.5.
If the measured value is less than 1.5, increase the dose by one quarter tablet each time.
If the measured value is more than 2.5, the dosage should be reduced by one quarter of a tablet each time.
If the measured value is >3.0, stop taking the drug for 2 days and take it again on the third day after taking blood test according to the result.
*Refer to the first, mainly refer to the second (INR International Normalized Ratio)
5. Timing of laboratory tests
(1) the first six months after surgery, diligent check, 5-7 days to check once, if the first six months of stable results, after the appropriate extension of the laboratory interval (2 weeks, 3 weeks, 4 weeks), the longest not more than 4 weeks, biological valve not combined with atrial fibrillation patients recommended 1 week laboratory test.
(2) If the volume is adjusted, retest 3 days after the volume is adjusted.
(3) Timely laboratory tests for bleeding tendencies, such as skin petechiae, bleeding gums, blood in the urine and stool, etc.
6. What factors affect the test results? What should I do if I have a disease? What should I pay attention to in my life?
Disease, diet, other drugs and large changes in lifestyle may affect the test results. If you are sick, please inform your physician that you are taking warfarin at the time of your visit and do not take any medication on your own!
Some foods in your diet may have an effect on the efficacy of the medication. In the short term, you do not need to abstain from eating, and ensure a balanced diet; stay away from high magnetic fields as much as possible, and if you need MRI (magnetic resonance imaging) six months after mechanical valve replacement, you should be under the guidance of your physician; quit smoking and alcohol, and avoid strenuous activities.
7. Suggestions
Record the time of examination, drug dosage, PT or INR value, and other medications in your own tabulation, so that you can dynamically observe the medication adjustment.
8. Department contact number: 0371-67967112 (doctor’s office), 0371-67967111 (nurse station) (office hours: 08:00-18:00).
All the medical staff of the Department of Cardiovascular Surgery of the First Affiliated Hospital of Zheng University wish you and your family happiness and health!
This article is authorized by Dr. Pei Yu.