Objective : To provide efficient medical care to patients taking warfarin by developing a system for sharing prothrombin time-international normalized ratio (PT-INR) monitoring data between clinic and pharmacy ; and to verify the functionality of this system.
Methods : Before a clinic appointment, patients visited a pharmacy to self-monitor PT-INR levels with the rapid measuring device Coagucheck. Pharmacists noted the following on a form shared between the clinic and the pharmacy : 1) compliance, 2) side effects, 3) diet, and 4) PT-INR. On the basis of this information, they noted their opinions on the appropriate warfarin dose. Each patient submitted the form to the clinic doctor, who then prescribed warfarin on the basis of the information recorded. After the consultation, the patient took this prescription to the pharmacy to obtain the required medication, and received from the pharmacist the dosage information based on the doctor's instructions. Thus, the sequence of the patient's visits was pharmacy-clinic-pharmacy.
Results : From one pharmacist's report, it was apparent that one patient whose PT-INR level was outside the target range was occasionally skipping a warfarin dose because of a misunderstanding about the treatment. The pharmacist recorded the patient's information on the form to inform the doctor. After consultation with the doctor, the pharmacist gave a detailed explanation on the purpose of taking warfarin. As a result, patient compliance improved and the PT-INR reached the target level after one month.
Discussion : Development of this system revealed that patients can receive appropriate warfarin treatment when information on PT-INR becomes available during clinical consultation and compliance is achieved. The system for sharing the patient's self-monitored PT-INR data between clinic and pharmacy is considered beneficial for the patient.