Measurement of Warfarin in the Oral Fluid of Patients Undergoing Anticoagulant Oral Therapy

BACKGROUND: Patients on warfarin therapy undergo invasive and expensive checks for the coagulability of their blood. No information on coagulation levels is currently available between two controls. METHODOLOGY: A method was developed to determine warfarin in oral fluid by HPLC and fluorimetric detection. The chromatographic separation was performed at room temperature on a C-18 reversed-phase column, 65% PBS and 35% methanol mobile phase, flow rate 0.7 mL/min, injection volume 25 µL, excitation wavelength 310 nm, emission wavelength 400 nm. FINDINGS: The method was free from interference and matrix effect, linear in the range 0.2-100 ng/mL, with a detection limit of 0.2 ng/mL. Its coefficient of variation was <3% for intra-day measurements and <5% for inter-day measurements. The average concentration of warfarin in the oral fluid of 50 patients was 2.5±1.6 ng/mL (range 0.8-7.6 ng/mL). Dosage was not correlated to INR (r = -0.03, p = 0.85) but positively correlated to warfarin concentration in the oral fluid (r = 0.39, p = 0.006). The correlation between warfarin concentration and pH in the oral fluid (r = 0.37, p = 0.009) confirmed the importance of pH in regulating the drug transfer from blood. A correlation between warfarin concentration in the oral fluid and INR was only found in samples with pH values ≥7.2 (r = 0.84, p = 0.004). CONCLUSIONS: Warfarin diffuses from blood to oral fluid. The method allows to measure its concentration in this matrix and to analyze correlations with INR and other parameters

The management of oral anticoagulant therapy: the patient's point of view

Abstract The aims of this study were to investigate on the general adhesion of the patients to oral anticoagulant therapy, and particularly on the quality of life of our patients, the doctor-patient relationship and the Centre-patient relationship. For this purpose we administered a questionnaire containing 17 main questions each with a maximum of 4 secondary questions. The questionnaire was administered to two groups of 127 and 137 oral anticoagulated patients (127 males and 137 females, mean age 55 +/- 19 years), followed at two Anticoagulation Clinics, in two Italian cities, Cagliari (Sardinia) and Padua (North East Italy). The cities differed in the number of patients monitored and the management modalities of anticoagulation. The results show that oral anticoagulant therapy does not limit the life-style of the patients. Only 11% of the patients complain of limitations to their daily life. Fifty-two percent believe their health has improved, and 87% are not afraid of negative c..

The management of oral anticoagulant therapy: the patient's point of view

The aims of this study were to investigate on the general adhesion of the patients to oral anticoagulant therapy, and particularly on the quality of life of our patients, the doctor-patient relationship and the Centre-patient relationship. For this purpose we administered a questionnaire containing 17 main questions each with a maximum of 4 secondary questions. The questionnaire was administered to two groups of 127 and 137 oral anticoagulated patients (127 males and 137 females, mean age 55 +/- 19 years), followed at two Anticoagulation Clinics, in two Italian cities, Cagliari (Sardinia) and Padua (North East Italy). The cities differed in the number of patients monitored and the management modalities of anticoagulation. The results show that oral anticoagulant therapy does not limit the life-style of the patients. Only 11% of the patients complain of limitations to their daily life. Fifty-two percent believe their health has improved, and 87% are not afraid of negative consequences. The doctor-patient relationship is considered very important by 96% of patients. Seventy-eight percent refer to the Anticoagulation Clinic also for other health problems, 93% consider it important to be assessed by the doctor at the Anticoagulation Clinic, while 83% believe the doctor should always hand out the results personally. We conclude that in general oral anticoagulant therapy is accepted by the majority of patients, in spite of the need for periodic monitoring. The doctor-patient relationship should be taken into account, even in the case of a monitored, computer-assisted method of dose-adjustment