Dose, international normalized ratio and influencing factors of long-term taking of warfarin in elderly patients with atrial fibrillation
ZHANG Wei
TIAN Guo-xiang
XIA Chang-quan
LI Juan
WU Yun-tao
Abstract：Objective To study the dose, international normalized ratio (INR) and influencing factors of long-term taking of warfarin in elderly patients with non-valvular atrial fibrillation (NVAF). Methods NVAF patients (n=110) with warfarin anticoagulation therapy for over 5 y, were divided, according to age, into age≥80 group (n=35), age=70-79 group (n=40) and age=65-69 group (n=35). The safe medication range and INR of long-term taking of warfarin was compared among 3 groups, and influencing factors on warfarin were observed. Results There was no case with acute cerebral infarction and other vascular thrombosis in 3 groups during taking warfarin, and incidence of bleeding events had no statistical difference among 3 groups (P>0.05). The difference in warfarin dose [(2.89± 0.52) mg/d vs. 2.99±0.41) mg/d] and INR [(2.15±0.31) vs. (2.21±0.30)] had no statistical significance between age≥80 group and age=70-79 group (P>0.05). The dose of warfarin [(3.39±0.61) mg/d] and INR (2.55±0.60) were significantly higher in age=65-69 group than those in age=≥80 group and age=70-79 group (P<0.05). The diseases influencing on warfarin dose and INR included mainly heart failure, abnormal thyroid function, dysfunction of liver and kidney, and administration of antibiotics and antiarrhythmic drugs. Conclusion INR controlled from 1.5 to 2.5 will be safe and effective in elderly NVAF patients (age>70) taking warfarin for anticoagulation treatment. There were many influencing factors on dose of warfarin, so INR should be monitored and the dose should be adjusted timely.
Keywords：Non-valvular atrial fibrillationWarfarinInternational normalized ratioSafety
Publication Date：2015-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：3( 448-450 )