Effects of Age, BMI and Creatinine Clearance on Edoxaban Plasma Concentrations in Non-Valvular Atrial Fibrillation Patients

Purpose Non-valvular atrial fibrillation (NVAF) is a major stroke risk factor, and edoxaban is commonly used for thromboprophylaxis. However, marked interindividual variability in plasma edoxaban exposure may raise bleeding or thromboembolism risk. This study aimed to determine plasma edoxaban concentrations and identify clinical and demographic factors associated with its variable exposure in NVAF patients. Methods This observational study enrolled 103 adult patients with NVAF receiving standard edoxaban therapy at Zhongda Hospital, Southeast University, from December 2024 to December 2025. Trough edoxaban concentrations were measured by validated high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Dose-normalized concentration (C/dose) was calculated to adjust for dosage differences. Pearson correlation analysis was performed to assess the associations between C/dose and age, body mass index (BMI), and creatinine clearance (CrCl). Results Of 103 patients, 70 (68.0%) received edoxaban 30 mg daily and 24 (23.3%) received 60 mg daily. Among those on 30 mg, trough concentrations were significantly higher in patients with moderate renal dysfunction than in those with mild dysfunction or normal renal function; among those on 60 mg, trough concentrations were significantly higher in patients with mild dysfunction than in those with normal renal function. Pearson correlation analysis showed that lower CrCl, older age, and lower BMI were significantly associated with higher edoxaban exposure. Conclusions Age, BMI, and renal function significantly influence edoxaban exposure in NVAF patients. Thus, for elderly patients with extreme body weight or renal dysfunction, measuring plasma edoxaban levels may help optimize efficacy and reduce the risk of bleeding.