Clinically Relevant Drug Levels

Monitoring direct oral anticoagulant levels might optimize the efficacy and safety for subpopulations of patients with atrial fibrillation or venous thromboembolism. However, determining the plasma concentration at presentation with bleeding or need for emergent surgery serves a different purpose. Threshold concentrations have been set empirically based on the knowledge of trough levels.

  • For patients who present with bleeding, direct oral anticoagulant concentrations of more than 50 ng/mL are considered high enough to warrant a reversal agent.
  • The threshold for major surgery is set at a maximum of 30 ng/mL.

Nevertheless, threshold values may be inappropriate and clinical judgment is required for individual patients.