| Objectives:To investigate the initial standard dose, the stable standard dose of warfarin and the time of target international normalized ratio (INR) in patients with atrial fibrillation in different age groups, and the safety during dose adjustment in patients, provide a better basis for clinic.Methods:Retrospective choice 89 outpatient and hospitalization treated with warfarin anticoagulation pointer between January 2008 and December 2012, they are through the strict screening and can adhere to the long-term follow-up of patients with chronic atrial fibrillation. They were assigned to three groups according to different ages, younger than 65 years old(Group 1), between 65 and 75 years old (Group 2), between 75 and 80 years old (Group 3). All patients should take warfarin at 16:00 daily with the initial warfarin dosages 3mg. The INR was measured on the 4th,6th,8th,10th day etc, between 8:00-9:00 am after took warfarin for one or two days. The dose of warfarin was adjusted according to INR, each gain reduction is 0.375-0.75mg, then measured the INR after adjusted dosages 2-3days, until INR was stabilized between 2.0 and 3.0. If the INR were all in the standard range after three measurements, it is considered as reaching the initial target, the dose of warfarin is considered as the initial standard dose. Then measured the INR weekly, if the INR were all in the standard range after two measurements, it is considered as reaching the stable target, the dose of warfarin is considered as the stable standard dose. Then measure the INR each month. When the INR is above the therapeutic range 3.0, need to stop the drug of the same day. And looked for the cause of INR fluctuations, such as the addition and subtraction of the combined medication, diet structure change, etc, then needed to monitor the INR daily until the INR< 3.0. Warfarin was reduced of 0.375-0.75 mg on the basis of the original treatment dose, and began to adjust the warfarin dose until INR standard and stability according.Observed the three groups of patients with the INR before taking the medicine, accompanied diseases, drug combination.Comparison of initial dose of Warfarin, a stable dose and standard time when the INR reached 2.0-3.0. And observed groups of bleeding, the incidence of thrombosis and embolism.Results:1 There was no significant difference on baseline data collected included demographic characteristics, for example accompanied diseases, drug combina-tion and the INR before taking the medicine.2 There was no significant difference on the initial standard INR and the stable standard INR after taking the medicine.3 The standard starting dose of the high age group is 2.62±0.70mg, significantly lower than the low age group and the elderly group(P<0.05), and the starting dose of elderly group was lower than the low age group. There was statistical significance between three groups (P<0.05). The maintenance dose of three groups respectively was3.64±0.51,3.02±0.60,2.57±0.46, the requiring dose of High age group patients was lower than low age group and the elderly group, and the elderly group was lower than the low age group (P<0.05)4 There was on statistical significance of the initial standard time and stable standard time beween three groups (P>0.05).5 There were 4 pations in Group 1,2 pations in Group 2,3 pations in Group 3 aboving the therapeutic range 3.0, but there were all no significant hemorrhage. There were not thromboembolism and important hemorrhage complication in 3 groups (P>0.05).Conclusion:When the INR was controlled in the scope of the target, the patients with chronic atrial fibrillation used warfarin is safe and effective. But because of the different ages, there are individual differences, the tolerance and sensitivity to warfarin may be different, so need to adjust the dose of warfarin according ages. In this work, the requiring dose of high age group patients was lower than low age group and the elderly group. But due to the control and monitor INR values strictly, adjusted the dose of warfarin timely, and in a timely manner in the wake of a bleeding time for processing, so there were not thromboembolism and important hemorrhage complication in 3 groups. So we summarize that when the High age patients with chronic atrial fibrillation application took warfarin of less initial standard dose, less maintenance dose is safe and effective. Through our research, there was no statistical significance of the initial standard time and stable standard time beween three groups, this suggested that the age is no significant influence on standard time. |
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