Development and implementation of a pharmacist-managed inpatient warfarin protocol

David L. Damaske, PharmD, and Robert W. Baird, MD

Because of the complexities of warfarin administration and its bleeding complications, a pharmacist-managed protocol for warfarin administration was developed at Baylor University Medical Center. The protocol incorporated current clinical guidelines and evidence-based medicine. Clinical outcomes under the protocol were compared with those of usual care, physician management, in a pilot study. Twenty-nine patients were enrolled in the protocol group and 22 in the control group between August 2004 and November 2004. Results showed that patients in both groups achieved therapeutic ranges of warfarin within 6 days. However, the pharmacist-managed patients exhibited a trend toward fewer adverse drug reactions (7% vs 14%) and fewer supratherapeutic international normalized ratios (17% vs 27%) than the control group, although the difference was not statistically significant. Based on these results and the results of similar larger studies showing the effectiveness of pharmacist-managed warfarin administration, Baylor University Medical Center made the protocol available for use in the hospital in May 2005.