Evaluation of Prothrombin Time in Patients on Warfarin Therapy at a Tertiary Hospital in Enugu State, South East Nigeria

This study evaluates the adequacy of prothrombin time (PT) and International Normalised Ratio (INR) monitoring in patients on warfarin anticoagulation therapy at the University of Nigeria Teaching Hospital (UNTH), Enugu State, South East Nigeria. Warfarin therapy requires close monitoring to maintain INR within the therapeutic range, and inadequate monitoring is a leading cause of both bleeding complications and thromboembolic events. A retrospective cross-sectional study reviewed the anticoagulation clinic records of 150 patients on warfarin therapy over two years. Data extracted included indication for anticoagulation, warfarin dose, frequency of INR monitoring, proportion of INR values within therapeutic range, and documented bleeding or thromboembolic events. Findings showed that only 52 percent of patients maintained INR within the recommended therapeutic range of 2.0 to 3.0 during the review period. Patients with mechanical heart valve replacement had the most erratic INR control. Frequency of INR monitoring was below recommended guidelines in 43 percent of patients, largely attributed to cost barriers and distance from the monitoring facility. Bleeding events occurred in 8.7 percent of patients. Supratherapeutic INR (above 4.0) was associated with significantly increased bleeding risk. The study recommends establishment of a dedicated anticoagulation management clinic with structured patient education, point-of-care INR devices, and financial assistance mechanisms for low-income patients at UNTH Enugu. Keywords: warfarin, INR monitoring, anticoagulation, prothrombin time, Enugu State.