Evaluation of a Pharmacist-Managed Anticoagulation Clinic

Background Anticoagulation therapy is important in the prevention and treatment of cardioembolic events. Warfarin is frequently used but requires continual monitoring to ensure safety and efficacy. The target time in therapeutic range (TTR) is not always achieved. Objectives The objectives for this study were to determine the TTR for a pharmacist-managed anticoagulation clinic and identify reasons for sub- and supratherapeutic international normalized ratio (INR) values. Methods Medical records for subjects prescribed warfarin were reviewed. Demographic and relevant clinical information was assessed. INR measurements were extracted for subjects enrolled. The TTR was calculated, and the cause for sub- or supratherapeutic values was determined when possible. Results One hundred twenty-six subjects were included in this retrospective study. The calculated TTR was 51%. The cause for more than 65% of the sub- and supratherapeutic INR values could not be determined. One subject incurred a clot and 6 subjects suffered a bleed. No deaths occurred. Age was the only factor that correlated with a supratherapeutic INR value ( r = −0.179, P = .045). Conclusion Pharmacists in the anticoagulation clinic are effectively managing patients who are taking warfarin by frequently maintaining INR values near or within the recommended therapeutic range. Very few negative outcomes occurred during the time of study.