Background Regarding therapeutic adherence to new oral anticoagulants (NOAC), several studies¹ have shown lower adherence in dabigatran-treated patients compared to rivaroxaban and apixaban. The NOAC introduction has fueled the phenomenon of switching from vitamin K antagonists (VKA) to NOAC, and vice versa, and also from NOAC to other NOAC.

Purpose The aim of this descriptive study is to evaluate adherence to therapy among NOAC-treated patients by basing the analysis on the therapeutic switches, ie the passages to another NOAC or VKA.

Material and methods Through the informatic flow of pharmaceutical prescriptions, we extracted the NOAC prescriptions from July 2013 to June 2016 in the Area Vasta 1 of the region. Patients who have taken dabigatran, rivaroxaban and apixaban have emerged from these prescriptions (edoxaban is excluded because it is available since October 2016). Adherent patients were those who did not switch to other anticoagulant therapy (NOAC or VKA) during the analysis period and in the following 6 months (until December 2016). Patients who had taken VKA before starting treatment with NOAC (the flow of prescriptions was investigated since January 2013) and patients who died during the analysis period or in the following 6 months were excluded from the study.

Results A total of 3428 patients started therapy with NOAC during the 3 years of analysis. We excluded 1512 patients who had previously taken VKA and 188 patients who died during the analysis period or in the following 6 months. At this point 1728 patients entered tthe analysis: 614 started treatment with dabigatran, 803 with rivaroxaban and 311 with apixaban. Among dabigatran patients, 519 (84.5%) did not record switches, 42 switched to VKA therapy and 53 to other NOAC. Among rivaroxaban patients, 746 (92.9%) did not record switches, 30 switched to VKA and 27 to NOAC. Among apixaban patients, 292 (93.9%) did not record switches, 30 switched to VKA and 27 to NOAC.

Conclusion Rivaroxaban and apixaban exhibit high adhesion to therapy and lower switching rates compared to dabigatran (7.1% and 6.1% versus 15.5%). These findings confirm lower adherence to dabigatran therapy.

Reference and/or Acknowledgements 1. Brown JD, et al. J Manag Care Spec Pharm2017;23(9):958–67.

No conflict of interest