Handeland G F, Abildgaard U, Holm H A, Arnesen K E
Medical Department, Aker Hospital, Oslo, Norway.
Eur J Clin Pharmacol. 1990;39(2):107-12. doi: 10.1007/BF00280041.
Two studies have been done to establish recommendations for dosage and dose adjustment in the treatment of deep vein thrombosis (DVT) with low molecular weight heparin (LMWH). In the first, 56 patients were randomized in a double blind study to be treated either with unfractionated heparin (UFH) or LMWH s.c. every 12 h. Initial doses were given according to age and sex, disregarding bodyweight, and the dose was then adjusted when the peak plasma heparin concentration fell outside the desired range of 0.5-0.8 anti-FXa U/ml. There were fewer dose adjustments in the LMWH group. The correlation between injected dose (U/kg bodyweight) and the heparin concentration was higher in the LMWH group (r = 0.59) than in the UFH group (r = 0.38). The results suggest that, in order to obtain the desired heparin concentration, the initial dose of LMWH should be about 100 U/kg bodyweight every 12 h. In the second, open study, this dosage plan was followed in 15 patients. The peak heparin concentration on Day 2 ranged from 0.40 to 0.75 anti-FXa U/ml and adjustment was only required in 3 patients. Day to day variation in peak heparin activity in the individual patient varied little (CV 11-22%), and there was no accumulation. The results indicate that plasma heparin concentration is more predictable using LMWH than UFH, and they point to definite advantages in the use of LMWH in a bodyweight adjusted dosage.
已开展两项研究，以确定低分子量肝素（LMWH）治疗深静脉血栓形成（DVT）时的剂量及剂量调整建议。第一项研究中，56例患者在双盲研究中被随机分组，分别接受普通肝素（UFH）或LMWH皮下注射，每12小时一次。初始剂量根据年龄和性别给予，不考虑体重，然后在血浆肝素峰值浓度降至0.5 - 0.8抗FXa U/ml的期望范围之外时调整剂量。LMWH组的剂量调整较少。LMWH组注射剂量（U/kg体重）与肝素浓度之间的相关性（r = 0.59）高于UFH组（r = 0.38）。结果表明，为获得期望的肝素浓度，LMWH的初始剂量应为每12小时约100 U/kg体重。在第二项开放性研究中，15例患者遵循了该剂量方案。第2天的肝素峰值浓度范围为0.40至0.75抗FXa U/ml，仅3例患者需要调整剂量。个体患者肝素峰值活性的每日变化很小（CV 11 - 22%），且无蓄积。结果表明，与UFH相比，使用LMWH时血浆肝素浓度更可预测，且表明在根据体重调整剂量使用LMWH方面具有明显优势。
