A Flexible Loading Dose Schedule for Warfarin Therapy

A flexible loading dose schedule for inducing anticoagulation with warfarin was assessed in 31 consecutive patients. 55% reached the therapeutic range (prothrombin ratio between 2 and 4:1) by Day 2 (40 hours after the first dose) and this figure rose to 77% on Day 3 and to 87% on Day 4. All patients had a PTR between 1.7 and 4.2 on Day 5. Patients with evidence of cardiac failure and abnormal liver function, and those taking medications known to interact with warfarin required lower doses and ran a higher PTR when compared with the total group of patients. This schedule offers a useful means of safely and rapidly inducing warfarin therapy in all patients.