Practical application of the 10-mg warfarin initiation nomogram

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. A retrospective cohort including all outpatients beginning concurrent treatment with warfarin and low-molecular-weight heparin over a 24-month period in our Thrombosis Unit was reviewed. Eight hundred and forty-one 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 international normalized ratio target of 2.0-3.0 within 5 days. Mean duration of low-molecular-weight heparin treatment was 6.0 ± 1.9 days, and 3.7% of patients had an international normalized ratio of at least 5.0 in the first 4 weeks of treatment. The 10-mg nomogram effectively results in an early therapeutic international normalized ratio with a good safety profile in 'real-life' daily practice.