Adjusted-Dose Enoxaparin for VTE Prevention in the Morbidly Obese

Abstract

Background: Venous thromboembolism (VTE) is a major health problem and common cause of morbidity and mortality in hospitalized patients. While trials in both surgical and medically ill patients have demonstrated efficacy and safety of enoxaparin for VTE prophylaxis (VTEP), they failed to adequately represent morbidly obese (body mass index > 40 kg/m 2) patients. Objective: To assess the impact of a weight-adjusted enoxaparin dosing algorithm on anti-factor Xa levels, thrombosis, and bleeding in morbidly obese patients. Methods: A retrospective chart review was conducted, which included morbidly obese patients receiving VTEP with adjusted-dose enoxaparin. Patients received enoxaparin 0.5 mg/kg subcutaneously once or twice daily based on VTE risk. An anti-factor Xa level was drawn 3 to 5 hours after 2 or more consecutive doses. The primary outcome was the percentage of patients achieving target anti-factor Xa levels, defined as 0.2 to 0.6 IU/mL. Secondary outcomes included the incidence of symptomatic VTE and major bleeding. Results: Of the 182 charts reviewed, 141 anti-factor Xa levels from 130 patients met inclusion criteria. The study population was 44% male, and the median body mass index was 45.6 kg/m 2. A total of 120 anti-factor Xa levels (85.1%) were within the target prophylactic range. Sixteen anti-factor Xa levels (11.3%) were below target range, and 5 (3.4%) were above range. The only significant difference among the 3 groups was baseline renal function (P = .035). There were 2 thromboembolic events and 1 major bleed in the study population. Conclusion: A weight-based VTEP dosing strategy for morbidly obese patients is effective without an apparent increase in adverse events.

Is Enoxaparin Sodium Exactly Safe For Subcutaneous Fibroblast?: A Cell Culture Study

“…The severity of skin reaction may vary depending on the age and sex of the patient, the presence of pregnancy or obesity. Obesity is an important factor for the dose adjustment of the medications used for prophylaxis or treatment of venous thromboembolism [21,22]. Although guidelines for the dose adjustment of enoxaparin sodium for overweight or obese patients have been published, the initial dose should be modified according to the body weight of an individual patient.…”

Enoxaparin for thromboprophylaxis in overweight and obese patients: a prescribing audit at a tertiary hospital

“…Most patients, regardless of weight or BMI, received standard 40‐mg/day doses. Given that over 50% of patients were overweight or obese with normal renal function, this finding suggests underdosing of enoxaparin prophylaxis, when reflecting on the body of literature recommending dose adjustment in overweight and obese patients …”

“…In overweight patients, weight‐based enoxaparin dosing, using total body weight, has been reported as effective at once‐daily doses of 0.4 and 0.5 mg/kg, as well as with doses of 0.5 mg/kg every 12 h . In patients with a body mass index (BMI) ≥30 kg/m 2 , fixed‐dose regimens of 40 mg enoxaparin twice daily have been shown to be effective .…”

Safety and Effectiveness of Reduced Dose Versus Standard Dose Enoxaparin Venous Thromboembolism Prophylaxis in Underweight Medically Ill Patients

“…There was only one bleeding event observed in the study. 2 Limited literature is available on dosing of prophylactic enoxaparin in the underweight patient population, and current major guidelines 3 do not comment on the optimal dosing strategy of prophylactic enoxaparin in this population. The aim of this study was to evaluate prophylactic enoxaparin dosing in medically ill patients less than 50 kg by comparing adverse outcomes when dosing is reduced to 30 mg subcutaneously daily from standard dosing of 40 mg subcutaneously daily or 30 mg subcutaneously twice daily.…”

“…Parikh et al 2 also examined prophylactic enoxaparin dosing in the overweight population using the 0.5 mg/kg subcutaneously daily or twice daily dosing strategy based on VTE risk. A total of 130 patients were included and 120 patients’ anti-Xa levels were within target range.…”