Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA.
Ann Pharmacother. 2012 Nov;46(11):e30. doi: 10.1345/aph.1R226. Epub 2012 Oct 16.
To report our experience of reduced-dose argatroban in a patient with suspected heparin-induced thrombocytopenia (HIT) and Child-Pugh class C liver disease and review the relevant literature to summarize current recommendations on argatroban use in patients with severe liver disease.
A 58-year-old male with Child-Pugh class C liver disease (Model for End-Stage Liver Disease [MELD] score = 31, total bilirubin 4.5 mg/dL) and hemodialysis-dependent renal failure was hospitalized with acute deep vein thrombosis (DVT). Three days after heparin initiation for DVT, he developed thrombocytopenia. Given his heparin exposure (both for treatment of DVT and ongoing hemodialysis), HIT was suspected and all heparinoids were immediately discontinued. Argatroban was initiated for the treatment of HIT while laboratory testing for HIT antibodies and the serotonin release assay were completed. Because of the patient's advanced liver disease, the starting dose of argatroban was reduced to 0.2 μg/kg/min, with frequent monitoring of the activated partial thromboplastin time (aPTT) (goal 60-85 seconds). Despite this dose reduction, the aPTT was supratherapeutic. Following further dose reductions, a final argatroban maintenance dose of 0.05 μg/kg/min was necessary for the attainment of goal aPTTs.
Reducing the starting dose of argatroban to 0.5 μg/kg/min is recommended in patients with liver disease. Nevertheless, this recommended dose is largely based on data from patients with more moderate liver disease (eg, Child-Pugh class A or B), and dosing in more advanced liver disease remains largely unexplored. Patients with more advanced liver disease may require additional dose reductions to avoid supratherapeutic concentrations of anticoagulation agents and to minimize bleeding risk.
This report illustrates the importance of careful selection of argatroban dosing and appropriate aPTT monitoring in patients with severe liver disease. Excessive anticoagulation may precipitate major bleeding complications, placing patients with this complicated disease at undue risk.
报告我们在一名疑似肝素诱导血小板减少症(HIT)合并 C 级肝功能障碍的患者中应用小剂量阿加曲班的经验,并复习相关文献,总结目前关于严重肝功能障碍患者应用阿加曲班的建议。
一名 58 岁男性,患有 C 级肝功能障碍(终末期肝病模型评分[MELD] = 31,总胆红素 4.5mg/dL)和依赖血液透析的肾功能衰竭,因急性深静脉血栓(DVT)住院。在开始用肝素治疗 DVT 后 3 天,他出现血小板减少。鉴于他接触肝素(既用于治疗 DVT,也用于正在进行的血液透析),怀疑发生 HIT,立即停用所有肝素类药物。因患者存在严重的肝功能障碍,阿加曲班的起始剂量减至 0.2μg/kg/min,同时频繁监测活化部分凝血活酶时间(aPTT)(目标 60-85 秒)。尽管降低了剂量,aPTT 仍高于治疗范围。进一步降低剂量后,需要将阿加曲班的最终维持剂量降低至 0.05μg/kg/min,才能达到目标 aPTT。
建议肝功能障碍患者将阿加曲班的起始剂量减至 0.5μg/kg/min。然而,该推荐剂量主要基于中重度肝功能障碍(如,Child-Pugh 分级 A 或 B)患者的数据,而在更严重肝功能障碍患者中的剂量调整仍基本未探索。更严重肝功能障碍的患者可能需要进一步降低剂量,以避免抗凝药物的治疗窗外浓度,并尽量降低出血风险。
本报告说明了在严重肝功能障碍患者中仔细选择阿加曲班剂量和适当 aPTT 监测的重要性。过度抗凝可能会引发严重的出血并发症,使患有这种复杂疾病的患者面临不必要的风险。