Practical Application of the 10 Mg Warfarin Initiation Nomogram

Introduction: Initiation of warfarin therapy is a clinical challenge. A 10 mg warfarin initiation nomogram was recently validated in a randomized controlled trial. We sought to determine the efficacy and safety of this 10 mg warfarin initiation nomogram in “real-life” daily practice.

Methods: A retrospective cohort including all outpatients beginning concurrent treatment with warfarin and low-molecular-weight-heparin (LMWH) over a 24 month period in our Thrombosis Unit was reviewed.

Results: 841 patients were included, of them 640 (76.1%) were started on the nomogram. The nomogram was entirely followed in 324 patients (38.5%). The efficacy and safety profile was similar to that observed in the original clinical trial: 86% of patients managed according to the nomogram reached the INR target of 2.0 to 3.0 within 5 days. Mean duration of LMWH treatment was 6.0 ± 1.9 days, and 3.7% of patients had an INR ≥ 5.0 in the first four weeks of treatment.

Conclusion: The 10-mg nomogram effectively results into an early therapeutic INR with a good safety profile in “real life” daily practice.