Effect of Patient Weight on the Anticoagulant Response to Adjusted Therapeutic Dosage of Low-Molecular- Weight Heparin for the Treatment ofVenous Thromboembolism

Abstract

Data evaluating the safety of using weight-based dosing of low-molecular-weight heparin (LMWH) in obese patients are limited. Some manufacturers have recommended a maximum daily dose of LMWH not to be exceeded. The purpose of this study was to determine if body weight influenced the anticoagulant response to a weight-based dose of LMWH for the treatment of venous thromboembolism. Patients with serum creatinine levels <150 µmol/l receiving the LMWH , dalteparin 200 anti-Xa IU/kg based on actual body weight subcutaneously once daily for the treatment of deep vein thrombosis or pulmonary embolism, were eligible for the study. Patients received a minimum of 5 days LMWH treatment. Patients had peak anti-Xa levels (IL Test Chromogenic assay) measured 3–4 h following their day 3 injection and trough anti-Xa levels measured immediately prior to injections on day 3 and 5. No dose adjustments were made on the basis of the anti-Xa levels. Patients were a priori stratified into three weight classes: (A) within 20% of ideal body weight (IBW) (n = 13); (B) 20–40% of IBW (n = 14), and (C) greater than 40% of IBW (n = 10). The largest patient weighed 190 kg and had a body mass index of 58. Mean daily LMWH doses were 14,030, 17,646 and 23, 565 IU for groups A, B and C, respectively. Mean (SD) trough anti-Xa levels on day 3 were 0.12 (0.05) anti-Xa IU/ml for group A, 0.11 (0.03) anti-Xa IU/ml for group B and 0.11 (0.03) anti-Xa IU/ml for group C (p > 0.2). Similar trough anti-Xa levels were observed on day 5. Mean (SD) peak anti-Xa levels on day 3 were 1.01 (0.20) anti-Xa IU/ml, 0.97 (0.21) anti-Xa IU/ml and 1.12 (0.22) anti-Xa IU/ml for groups A, B and C, respectively (p > 0.2). No thromboembolic or bleeding complications occurred during LMWH therapy in any patients. These findings suggest that body mass does not appear to have an important effect on the response to LMWH up to a weight of 190 kg in patients with normal or near normal renal function.

Initial Treatment of Venous Thromboembolism

“…9 Supporting the use of anti-factor Xa monitoring in patients with renal failure is the different potential for accumulation among the various LMWH preparations and the absence of a clear threshold of creatinine clearance for identification of patients at increased risk for accumulation. 41 Obese patients have been under-represented in treatment trials using LMWH, and although individual LMWH preparations have shown predictable antifactor Xa levels in this patient group, 42,43 measuring levels on at least 1 occasion seems prudent.…”

Thromboseprophylaxe in der bariatrischen Chirurgie

“…Das gleiche fand sich für Tinzaparin bis 165 kg (24) und für Dalteparin bis zu 190 kg (25)(26)(27). Allerdings waren in diese Studien nur zufällig einige Patienten mit hohem BMI eingeschlossen.…”

Anticoagulação na fase aguda

“…Os trabalhos que avaliaram esse subgrupo usaram o peso atual dos pacientes para o cálculo da dose da HBPM a ser usada. (16)(17)(18)(19) Em pacientes com insuficiência renal grave, deve-se usar preferencialmente a HNF ao invés da HBPM. (C) A infusão contínua de HNF i.v.…”