Use Patterns and Unlabeled Uses of Target-Specific Oral Anticoagulants: A Single-Center Experience

Background: Target-specific oral anticoagulants (TSOAs) have advantages and disadvantages over warfarin, and they differ by indication, dosage adjustment, and drug interactions. Objective: The purpose of this retrospective cohort study is to determine use patterns and unlabeled uses of TSOAs. Methods: From July 1, 2012, to April 30, 2014, orders for warfarin, dabigatran, rivaroxaban, or apixaban in a tertiary medical center were included. Electronic medical records were reviewed to collect information regarding characteristics of the patients receiving these medications. Unlabeled use was defined as an indication or dose not approved by the US Food and Drug Administration. The percentage of orders for each study drug per month and the percentage of orders for each TSOA that contained an unlabeled use were calculated. Results: Of a total of 869 orders, 140 (16.1%) were for TSOAs (13 dabigatran, 97 rivaroxaban, and 30 apixaban orders). Compared with the first 4 months of the study period, the monthly percentage of orders for a TSOA increased by 2.5-fold in the last 4 months. Of the 3 TSOAs, only orders for dabigatran decreased (5.6% in July 2012 vs 0% in April 2014). Of the 140 TSOA orders, 28 (20.0 %) were unlabeled uses (3 unlabeled indications and 25 unlabeled dose), which included 16 unlabeled renally adjusted doses. The percentage of unlabeled uses did not significantly differ by TSOA. Conclusion: The use of TSOAs has increased and unlabeled uses are common. These data provide opportunities for quality improvement in the use of TSOA in clinical practice.