Which Factors Determine the Success of Anticoagulation with Warfarin

Abstract

Background: Warfarin is a drug most commonly used for anticoagulation. Its efficiency depends on remaining in the demanded therapeutic range. Objectives: In this study, the relation between the time in therapeutic range (TTR) and sociodemographic characteristics, comorbidities, and drugs used was investigated for the patient’s use of warfarin. Methods: Among patients admitted to the Internal Diseases Polyclinic or taking inpatient treatment in internal diseases service, 50 female and 50 male patients using warfarin were selected starting from the closest date based on their admittance dates. Using patient files and hospital automation system data, TTR levels were calculated with the Rosendaal method, and sociodemographic characteristics, comorbidities, and drugs used were recorded. Patients were separated into 2 groups, TTR > 60% and TTR < 60%, and relations between sociodemographic characteristics, comorbidities, and drugs used were investigated among these groups. Results: Time in therapeutic range was found to be over 60% in 34% of the patients. It was observed that gender, occupation and education level, body mass index, smoking ratios, comorbid diseases, drugs used, serum creatinine, and alanine aminotransferase (ALT) levels were similar among TTR groups. The use of drugs lowering the warfarin effect was found to be similar among TTR groups. Conclusions: It was observed that sociodemographic characteristics, comorbid diseases, used drugs, serum creatinine, and ALT levels of the patients didn't affect the time in the therapeutic range.