Sridharan Kannan, Banna Rashed Al, Husain Aysha
Department of Pharmacology & Therapeutics, College of Medicine and Medical Sciences, Arabian Gulf University, Manama, Kingdom of Bahrain.
Department of Cardiology, Salmaniya Medical Hospital, Ministry of Health, Manama, Kingdom of Bahrain.
Curr Drug Saf. 2023;18(1):23-30. doi: 10.2174/1574886317666220429103847.
To identify the extent and associated factors for patients with prolonged prothrombin time, international normalized ratio (PT-INR), and the dosage modifications were carried out with warfarin.
Studies evaluating patients on warfarin with supratherapeutic anticoagulation are limited. It is vital to understand the management strategies for patients receiving warfarin who are bleeding and those with only supratherapeutic PT-INR.
To evaluate the factors associated with supratherapeutic anticoagulation without bleeding with warfarin.
A cross-sectional study was carried out on patients receiving long-term warfarin with at least one PT-INR value > 3.2. Percent time in therapeutic range (TTR) was calculated and National Institute for Health and Care Excellence (NICE) guidelines were adhered to defining anticoagulation control into good (> 65%) and poor (< 65%).
One hundred and forty-four patients were recruited. Nearly half of the study population had PT-INR values between 3.2 and 3.9. On average, individuals had at least 4 times PT-INR values in the supratherapeutic range. Elderly patients were observed with a significant trend of supratherapeutic INR. Duration of therapy was significantly correlated with the risk of PT-INR > 4. Lower TTR was observed in patients with frequent PT-INR > 4 and those patients had significantly poor anticoagulation control. Duration of warfarin therapy and HAS-BLED scores were observed to be significant predictors of supratherapeutic INR. Large variations were observed in the modifications of warfarin dose carried out at various supratherapeutic INR values and consequently PTINR values.
We observed that the majority of patients with supratherapeutic INR had their INR values between 3.2 and 3.9. Elderly patients, with higher HAS-BLED scores and prolonged duration of warfarin therapy, were observed with an increased risk of supratherapeutic anticoagulation. Careful dosage modifications are needed particularly in high-risk categories as mentioned above.
确定凝血酶原时间延长、国际标准化比值（PT-INR）的患者范围及相关因素，并对华法林进行剂量调整。
评估接受华法林治疗且抗凝作用超治疗范围的患者的研究有限。了解接受华法林治疗的出血患者和仅PT-INR超治疗范围患者的管理策略至关重要。
评估华法林治疗时无出血但抗凝作用超治疗范围的相关因素。
对接受长期华法林治疗且至少有一次PT-INR值>3.2的患者进行横断面研究。计算治疗范围内时间百分比（TTR），并遵循英国国家卫生与临床优化研究所（NICE）指南将抗凝控制定义为良好（>65%）和不佳（<65%）。
招募了144名患者。近一半的研究人群PT-INR值在3.2至3.9之间。平均而言，个体的PT-INR值至少有4次处于超治疗范围。观察到老年患者的INR有超治疗范围的显著趋势。治疗持续时间与PT-INR>4的风险显著相关。PT-INR频繁>4的患者TTR较低，且这些患者的抗凝控制明显不佳。观察到华法林治疗持续时间和HAS-BLED评分是超治疗INR的显著预测因素。在不同超治疗INR值及相应PT-INR值时进行的华法林剂量调整存在很大差异。
我们观察到大多数INR超治疗范围的患者其INR值在3.2至3.9之间。观察到老年患者、HAS-BLED评分较高且华法林治疗持续时间较长者，抗凝作用超治疗范围的风险增加。特别是在上述高危类别中，需要谨慎进行剂量调整。
