Nathaniel R Thompson-Moore1, Matthew A Wanat2, David R Putney2, Phuong H Nguyen Liebl2, Wayne L Chandler3, James E Muntz4. 1. Department of Pharmacy, Houston Methodist Hospital, Houston, TX, USA nthompson-moore@houstonmethodist.org. 2. Department of Pharmacy, Houston Methodist Hospital, Houston, TX, USA. 3. Department of Pathology, Houston Methodist Hospital, Houston, TX, USA. 4. Department of Medicine, Houston Methodist Hospital, Houston, TX, USA.
Abstract
BACKGROUND: The pharmacokinetic properties of enoxaparin may lead to supratherapeutic antifactor Xa (anti-Xa) levels and increased bleeding when standard treatment doses are used in patients with morbid obesity. OBJECTIVE: To evaluate the dose of enoxaparin needed to achieve therapeutic anti-Xa levels in a prospective, masked observational cohort of heterogeneous inpatients with morbid obesity and to determine whether patients with morbid obesity treated with 1 mg/kg of enoxaparin are at increased risk of supratherapeutic levels and bleeding events compared to patients receiving lower doses. METHODS: Hospitalized patients with a body mass index ≥40 kg/m(2) or actual body weight ≥140 kg and prescribed treatment doses of enoxaparin >60 mg per day were enrolled and consented to phlebotomy for determination of anti-Xa levels. RESULTS: Forty-one patients were included for data analysis. The dose of enoxaparin that resulted in therapeutic and supratherapeutic anti-Xa levels at steady state was 0.83 mg/kg and 0.98 mg/kg (-0.11; 95% confidence interval [CI] -0.20 to -0.01, P = .02), respectively. Enoxaparin dose as mg/kg of actual body weight was an independent predictor of having a supratherapeutic anti-Xa level. Patients with doses <0.95 mg/kg versus ≥0.95 mg/kg were less likely to have supratherapeutic levels (odds ratio 0.21 [95% CI 0.05-0.84], P = .02) and had similar rates of subtherapeutic levels. Doses <0.95 mg/kg and ≥0.95 mg/kg resulted in similar bleeding rates of 17.9% and 22.2% (P = .71), respectively. CONCLUSION: Patients with morbid obesity required less than the recommended 1 mg/kg enoxaparin dose to achieve therapeutic peak anti-Xa levels; therefore, initiation with lower dosages is prudent and anti-Xa monitoring should guide dosage adjustments.
BACKGROUND: The pharmacokinetic properties of enoxaparin may lead to supratherapeutic antifactor Xa (anti-Xa) levels and increased bleeding when standard treatment doses are used in patients with morbid obesity. OBJECTIVE: To evaluate the dose of enoxaparin needed to achieve therapeutic anti-Xa levels in a prospective, masked observational cohort of heterogeneous inpatients with morbid obesity and to determine whether patients with morbid obesity treated with 1 mg/kg of enoxaparin are at increased risk of supratherapeutic levels and bleeding events compared to patients receiving lower doses. METHODS: Hospitalized patients with a body mass index ≥40 kg/m(2) or actual body weight ≥140 kg and prescribed treatment doses of enoxaparin >60 mg per day were enrolled and consented to phlebotomy for determination of anti-Xa levels. RESULTS: Forty-one patients were included for data analysis. The dose of enoxaparin that resulted in therapeutic and supratherapeutic anti-Xa levels at steady state was 0.83 mg/kg and 0.98 mg/kg (-0.11; 95% confidence interval [CI] -0.20 to -0.01, P = .02), respectively. Enoxaparin dose as mg/kg of actual body weight was an independent predictor of having a supratherapeutic anti-Xa level. Patients with doses <0.95 mg/kg versus ≥0.95 mg/kg were less likely to have supratherapeutic levels (odds ratio 0.21 [95% CI 0.05-0.84], P = .02) and had similar rates of subtherapeutic levels. Doses <0.95 mg/kg and ≥0.95 mg/kg resulted in similar bleeding rates of 17.9% and 22.2% (P = .71), respectively. CONCLUSION:Patients with morbid obesity required less than the recommended 1 mg/kg enoxaparin dose to achieve therapeutic peak anti-Xa levels; therefore, initiation with lower dosages is prudent and anti-Xa monitoring should guide dosage adjustments.
Authors: Claudia M Hanni; Sheila M Wilhelm; Bianca Korkis; Elizabeth A Petrovitch; Kanella V Tsilimingras; Sean M McConachie Journal: Hosp Pharm Date: 2018-09-22
Authors: Jacqueline G Gerhart; Fernando O Carreño; Matthew Shane Loop; Craig R Lee; Andrea N Edginton; Jaydeep Sinha; Karan R Kumar; Carl M Kirkpatrick; Christoph P Hornik; Daniel Gonzalez Journal: Clin Pharmacol Ther Date: 2022-05-18 Impact factor: 6.903