Introduction: There is no validated method to predict the daily maintenance dosage of oral anticoagulation treatment by fluindione in the elderly patients. The aim of our prospective study was to look for a relation between INR at day 2 after a fixed dosage of fluindione and the daily maintenance dosage of fluindione necessary to obtain an INR value between 2 and 3.
Patients and methods: Ten milligrams of fluindione were administered on first and second day of treatment. INR was determined the third day.
Results: From this value, we were able to determine the daily dosage of fluindione (+/- 5mg) that maintained a steady state INR value between 2 and 3.
Conclusion: In these very elderly patients, there was a relation between INR at the third day after a fixed dosage of fluindione and the daily maintenance dosage of fluindione necessary to obtain an INR value between 2 and 3.