Schwartz Rowena N
University of Pittsburgh, UPMC Cancer Pavilion, Room 430, 5150 Centre Avenue, Pittsburgh, PA 15232, USA.
Am J Health Syst Pharm. 2005 Nov 15;62(22 Suppl 5):S7-9. doi: 10.2146/ajhp050431.
One of the standard treatments for cancer-associated thrombosis has been initial therapy with unfractionated heparin (UFH) followed by long-term therapy with an oral anticoagulant (i.e., warfarin). However, characteristics associated with these two agents may make them suboptimal for many cancer patients. This article will explore some of the considerations and limitations when using UFH and warfarin in the cancer population and will also utilize case studies to emphasize the importance of individualized care.
UFH is an effective anticoagulant when doses are adjusted to maintain the activated partial thromboplastin time (aPTT) within a specified therapeutic range. However, due to the complex pharmacokinetics of this agent, patients must undergo frequent monitoring to maintain a therapeutic aPTT. In addition, UFH can be associated with serious adverse events including osteoporosis, heparin-induced thrombocytopenia, and bleeding. Similar to UFH, warfarin requires frequent monitoring and dose adjustments to maintain the International Normalized Ratio (INR) within the therapeutic range of 2.0 to 3.0. Warfarin also has numerous drug-herbal, drug-food, and drug-drug interactions, including interactions with many commonly used anti-tumor therapies. Complications related to UFH and warfarin in the treatment of cancer-associated thrombosis have gradually been minimized with the increased use of low molecular weight heparins (LMWHs), which are associated with reduced incidence of bleeding, heparin-induced thrombocytopenia, and drug interactions. In addition, LMWHs allow for convenient daily dosing without requiring routine monitoring and the option of home therapy.
When deciding on the optimal anticoagulant strategy, pharmacists must take into account the unique characteristics and needs of each individual patient as well as the specifics of the various anticoagulant therapies. Future strategies for the initial and long-term treatment of cancer-associated thrombosis may increasingly incorporate LMWHs because of factors related to safety and convenience.
癌症相关血栓形成的标准治疗方法之一是先用普通肝素（UFH）进行初始治疗，然后用口服抗凝剂（即华法林）进行长期治疗。然而，与这两种药物相关的特性可能使其对许多癌症患者而言并非最佳选择。本文将探讨在癌症患者中使用UFH和华法林时的一些注意事项和局限性，还将通过案例研究来强调个体化治疗的重要性。
当调整剂量以维持活化部分凝血活酶时间（aPTT）在特定治疗范围内时，UFH是一种有效的抗凝剂。然而，由于该药物复杂的药代动力学，患者必须频繁监测以维持治疗性aPTT。此外，UFH可能与严重不良事件相关，包括骨质疏松、肝素诱导的血小板减少症和出血。与UFH类似，华法林也需要频繁监测和剂量调整以维持国际标准化比值（INR）在2.0至3.0的治疗范围内。华法林还存在众多药物 - 草药、药物 - 食物和药物 - 药物相互作用，包括与许多常用抗肿瘤疗法的相互作用。随着低分子量肝素（LMWH）使用的增加，在治疗癌症相关血栓形成中与UFH和华法林相关的并发症已逐渐减少，LMWH与出血、肝素诱导的血小板减少症和药物相互作用的发生率降低相关。此外，LMWH允许方便的每日给药，无需常规监测，并且可以选择在家治疗。
在决定最佳抗凝策略时，药剂师必须考虑每个患者的独特特征和需求以及各种抗凝疗法的具体情况。由于与安全性和便利性相关的因素，癌症相关血栓形成的初始和长期治疗的未来策略可能会越来越多地纳入LMWH。
