Efficacy and Safety of Warfarin Therapy: Comparison Between Specialized INR Clinic and General Medical Clinic

Abstract

Background: Although warfarin is known as effective oral anticoagulant to prevent thromboembolic events, its’ narrow therapeutic index requires ambient and good follow-up to reduce its therapeutic complications. There is a continuous debate whether the best practice to accomplish this goal is in a specialized international normalized ratio clinic (INR-C) or in a general medical clinic (General-C). Few, if any, studies have been done in Sudan to compare the safety and efficacy of anticoagulant therapy in those clinics. Thus, the objective of this study was to compare the efficacy and safety of anticoagulant therapy in INR-C and in General-C. Methods: This is a prospective hospital-based study where 200 patients were divided into two groups (group A and B) of 100 patients. Group A were in the INR-C at Ahmed Gasim specialized hospital and group B in the General-Cat AL-Shaab teaching hospital. The study was conducted from September 2019 to April 2020. All patients were on warfarin treatment and regular follow-ups were conducted. Demographic and clinical data were collected and analyzed statistically using SPSS version 20. Ethical approval was obtained from the ethical committee of the Sudanese Medical Specialization Board (SMSB). Results: Of the 200 patients, 118/59% were females and 82/41% were males. Target international normalized ratio (INR) for group (A) was achieved in 56% of the patients in the first visit, increased to 63% in the second visit, and 75% in the third follow-up, compared with 24% of the patients from group (B) in the initial and second follow-up visit, to 43% in the third visit (P value=0.05). Knowledge about drug and food interaction of coagulation agents was higher (91%) among patients in group (A) compared with group (B) (56%). Drug interaction awareness was found in 89% of the patients in group (A) compared with only 40% in group (B) (P value=0.05). Major bleeding was reported in 2% and 14% of the patients of group (A) and (B) respectively, whereas minor bleeding was seen in 4% of group (A) and 11% of group (B). Conclusion: The study showed that INR-C is more efficient and safer for patients on regular warfarin therapy compared with the General-C.