Optimizing Enoxaparin Dosing in Asian Patients: The Critical Role of Age and Renal Function in Achieving Target Anti-Xa Levels

Objective: To investigate the roles of age and renal function in optimizing enoxaparin dosage for achieving target anti-Xa levels in Asian patients. Methods: A total of 135 patients subjected to enoxaparin therapy were retrospectively enrolled. Baseline demographic characteristics, clinical indicators, and laboratory test results were collected. The distribution patterns of weight-adjusted doses and anti-Xa levels were analyzed. Dose-response curves were employed to evaluate the probability of achieving therapeutic anti-Xa levels in different age groups (< 80 years vs ≥ 80 years) and estimated glomerular filtration rate (eGFR) categories (eGFR < 60 mL/min vs ≥ 60 mL/min). Results: The dose distribution revealed discrepancies between actual weight-adjusted doses and manufacturer-recommended doses in some patients. Age significantly influenced the attainment of target anti-Xa levels, whereas renal function exhibited no significant impact. Dose-response curves demonstrated that patients aged ≥ 80 years required lower doses to achieve 90– 95% target anti-Xa levels compared to those < 80 years. No significant difference was observed in target attainment between patients with eGFR < 60 mL/min and those with eGFR ≥ 60 mL/min. Conclusion: Within the range of eGFR ≥ 30 mL/min/1.73 m 2 , advanced age, rather than mild-to-moderate renal impairment, emerged as the critical factor for achieving target anti-Xa levels with enoxaparin in Asian patients. Patients aged ≥ 80 years required lower doses compared to younger patients. These findings still need prospective validation. Keywords: enoxaparin, Asian patients, anti-Xa levels, age, renal function