Peak and Trough Concentration Ranges of Factor Xa Inhibitors for Preventing Thromboembolic Stroke in Korean Patients with Non-valvular Atrial Fibrillation

BACKGROUND: Current guidelines recommend factor IIa- or Xa-specific inhibitors over warfarin analogs for preventing thromboembolic stroke in patients with atrial fibrillation (AF). However, their plasma concentrations in Korean patients are not well understood. METHODS: We conducted a single-center laboratory study to determine the distribution ranges of peak and trough concentrations of three factor Xa inhibitors (apixaban, edoxaban, and rivaroxaban) prescribed for preventing strokes in patients with AF. Patients receiving one of these drugs and undergoing blood specimen collection for laboratory tests were screened. Blood specimens were obtained from patients who had adhered to the prescribed drug regimen consistently for at least 1 week. Drug plasma concentrations were measured using heparin liquid-reagent technology-based anti-Xa chromogenic assays. RESULTS: We selected 459 patients who were taking standard or on-label-reduced doses of apixaban (N=252), edoxaban (N=182), or rivaroxaban (N=25). The 5th-95th percentile ranges of the peak concentrations were 84-414 ng/mL (apixaban), 72-424 ng/mL (edoxaban), and 97-517 ng/mL (rivaroxaban). The respective 5th-95th percentile ranges of the trough concentrations were 44-237 ng/mL, 23-93 ng/mL, and 13-219 ng/mL. Approximately 19.6% (apixaban), 33.3% (edoxaban), and 64.0% (rivaroxaban) of patients in each group had peak concentrations out of the predicted distribution ranges based on pharmacokinetic data. Approximately 7.3%, 52.8%, and 8.3% of patients had trough concentrations out of the predicted distribution ranges. CONCLUSIONS: A considerable proportion of Korean patients with AF taking factor Xa inhibitors may require population-specific reference ranges to guide therapeutic monitoring.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

Peer-reviewed pharmacology and drug-development research relevant to anticoagulants and leech-derived compounds. Indexed in PubMed and verified against the NCBI record.

Leech-derived molecules this paper discusses, each with a full profile in the ASH compound registry:

Explore how this research connects to clinical practice

More peer-reviewed studies in Drug Development.

• Novel Leech Antimicrobial Peptides — Hirunipins — Kumar et al. (2025)
• Medicinal Leech Genome Assembly — Anticoagulant Gene Catalog — Kvist et al. (2020)
• Effects of hirudotherapy on liver functions, lipid profile, and insulin sensitivity in rats with metabolic syndrome — Bilden A et al. (2026)
• HIRUDOTHERAPY IN PRESBYACUZIS PRAECOX IN CLEAN-UP WORKERS AFTER THE CHORNOBYL ACCIDENT DURING THE POST-CATASTROPHE YEARS — Zabolotnyi D, Mishchanchuk N (2019)
• [Hirudo medicinalis-leech applications in plastic and reconstructive microsurgery--a literature review] — Knobloch K et al. (2007)
• Recombinant hirudin in clinical practice: focus on lepirudin — Greinacher A, Lubenow N (2001)
• In-vitro antileishmanial potential of peptide drug hirudin — Khan H et al. (2017)
• Parenteral anticoagulants: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines — Garcia DA, Baglin TP, Weitz JI, Samama MM (2012)
• Direct thrombin inhibitors — Lee CJ, Ansell JE (2011)
• Updates on Use and Monitoring of Direct Thrombin Inhibitors — Navaei A et al. (2026)

Browse all ASH-analysed research →