Drug Therapy Interactions with New Oral Anticoagulants in Oncology Patients: a Retrospective Database Analysis 2013 - 2015

Abstract

Objectives: To identify common and serious drug-drug interactions involving novel anticoagulant drugs in cancer patients. Subjects: 60 patients who were treated at the Banner University of Arizona Cancer Center between November 1, 2013 and April 1, 2015 with rivaroxaban, dabigatran, or apixaban. Methods: A retrospective chart review was performed for patients who received a NOAC (novel oral anticoagulant) to determine if a medication regimen contained a drug-drug interaction involving the NOAC. Results: When analyzing the DDIs involving rivaroxaban, dabigatran, and apixaban, Micromedex® detected a total of 123 interactions, compared to Lexicomp®, which detected 111 interactions. When using Lexicomp®, there were 59 (32%) instances of no detected interactions, 19 (10%) moderate interactions, 27 (15%) major interactions, and 65 (36%) contraindicated DDIs with rivaroxaban. When using Micromedex®, there were 47 (26%) instances where no interaction was detected, 4 (2%) moderate interactions, and 119 (65%) major interactions, and no interactions were classified as contraindicated with rivaroxaban. Lexicomp® detected 3 (50%) interactions as major, and found no DDIs in 3 (50%) instances for dabigatran, and detected 1 (7%) moderate, 2 (14%) major and 6 (43%) contraindicated interactions for apixaban. Micromedex® detected 3 (50%) interactions as major, and found no DDIs in 3 (50%) instances for dabigatran, and detected 12 (86%) of interactions as major and found no DDIs in 2 (14%) instances for apixaban. Conclusions: There was significant variation in DDI detection between current literature4,5 and the drug information databases, Lexicomp® and Micromedex®, however most interactions detected were major or contraindicated.