Efficacy and safety of a pharmacist-managed inpatient anticoagulation service for warfarin initiation and titration

Summary What is known and Objective: Anticoagulation consultations provided by a pharmacist‐staffed inpatient service, similar to the experience reported in outpatient anticoagulation clinics, can potentially improve anticoagulation control and outcomes. At Tan Tock Seng Hospital, a 1200‐bed acute care teaching hospital in Singapore, pharmacist‐managed anticoagulation clinics have been in place since 1997. Pharmacist‐managed services were extended to inpatient consultations in anticoagulation management from April 2006. Our objective was to assess the effect of implementing a pharmacist‐managed inpatient anticoagulation service. Methods: This was a single‐centre cohort study. Baseline data from 1 January 2006 to 31 March 2006 were collected and compared with post‐implementation data from 1 April 2006 to 31 March 2007. Patients newly started on warfarin for deep vein thrombosis, pulmonary embolism or atrial fibrillation in general medicine and surgery departments were included. The three endpoints were as follows: (i) percentage of international normalized ratios (INRs) achieving therapeutic range within 5 days, (ii) INRs more than 4 during titration and (iii) subtherapeutic INRs on discharge. Results and Discussion: A total of 26 patients in the control period were compared with 144 patients who had received dosing consultations by a pharmacist during the initiation of warfarin. The provision of pharmacist consult resulted in 88% compared to 38% (P