Detection and management of clinically relevant drug-drug interactions with direct oral anticoagulants: an intervention study in community pharmacies

Introduction: 

Direct oral anticoagulants (DOACs) are increasingly used and can be involved in clinically relevant drug-drug interactions (DDIs) that increase the risk of major bleeding or thromboembolism. Skilled drug interaction management is essential to ensure safe and effective use of DOACs. In this study, we aimed to investigate the impact of the detection and management of DDIs with DOACs in a real-life community pharmacy setting on the pharmacotherapy of DOAC users. 

Methods: 

We conducted an intervention study in 201 community pharmacies in Belgium. On random days, patients purchasing DOACs or drugs known to interact with them were screened. When a DDI with the DOAC was detected, the pharmacist contacted the prescribing physician to discuss the management of the interaction. A previously developed practice-oriented DDI list accompanied by management plans for ambulatory care was used for both screening and management of the DDIs. 

Results: 

In total, 751 patients were included, among whom 875 DDIs were identified, primarily pharmacodynamic DDIs (95.7 %). Predominant interacting drug classes included selective serotonin or serotonin and norepinephrine reuptake inhibitors (32.9 %), antiplatelets (30.9 %), and non-steroidal anti-inflammatory drugs (28.9 %). In 43.0 % of DDIs, an intervention was decided upon. At three-month follow-up, proposed pharmacotherapy changes had been implemented in 79.1 % of these DDIs. 

Conclusions: 

This study demonstrates that active screening and management of DDIs with DOACs in community pharmacies, in close collaboration with prescribing physicians, resulted in changes in pharmacotherapy in a substantial number of patients. This may contribute significantly to the safer utilisation of DOACs in high-risk populations.