MedWire News: US researchers say that enoxaparin administered at a 0.5-mg/kg dose may be effective at preventing thrombosis in morbidly obese patients without increasing the risk for bleeding.
“Current practice guidelines recommend utilizing weight-based dosing of LMWH in obese patients, but do not provide specific dosing guidance,” explain Matthew Rondina (University of Utah, Salt Lake City) and co-workers.
To investigate weight-based dosing further, the team recruited 28 medically ill patients with a body mass index of 35 kg/m2 or higher who required thromboprophylaxis. Half (46%) the patients were female, they were aged an average of 54 years, and had an average BMI of 48.1 kg/m2.
The patients were given enoxaparin 0.5 mg/kg and peak anti-Xa levels were measured 4–6 hours after treatment.
They received an average daily dose of 67 mg, and the average peak anti-Xa level was 0.25 U/ml, and no patient had a therapeutic peak anti-Xa level. There was no significant correlation between peak anti-Xa and the patients’ weight or BMI.
“Based upon dosing in these patients with total body weights up to 210 kg (BMI 85.2 kg/m2), there did not appear to be a weight above which the dose of enoxaparin should be capped,” Rondina et al comment in the journal Thrombosis Research.
None of the patients experience symptomatic venous thromboembolism, bleeding, or significant thrombocytopenia.
“We found that a specific weight-based dose of enoxaparin (0.5 mg/kg subcutaneously once daily without capping the dose) is feasible and results in peak anti-Xa levels within or near the recommended range for thromboprophylaxis, without any evidence of excessive anti-Xa activity,” the team concludes.
Nevertheless, the researchers caution: “Additional clinical outcome studies evaluating this regimen are necessary to determine its reproducibility, safety, and efficacy.
“In the interim, clinical judgment and application of pharmacodynamicbased information is prudent.”
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