Drug-Drug Interactions with Oral Anticoagulants among High-Risk Non-Valvular Atrial Fibrillation Patients

Aim

The aim of this study is to clarify the most common medication and food supplements that can potentially interact with oral anticoagulants – rivaroxaban, dabigatran and warfarin.

Materials and methods

This study was conducted in Pauls Stradins Clinical university hospital, Latvian Centre of Cardiology during the time period prom October 2016 till June 2018. Patients with high-risk atrial fibrillation (CHAD2S2-VASc score more or equal 2 for men and more or equal 3 for woman) that use oral anticoagulants – rivaroxaban, dabigatran or warfarin, daily were included.

Results

402 patients were included - 219 (54.5%) female and 192 (45.5%) male, the mean age of 71.4 years. 209 (51.9%) had a potential drug interaction risk. Warfarin users (206; 51.2%) 0.5% (1) had potential drug interaction risk with selective serotonin reuptake inhibitors (SSRIs), rosuvastatin – 17 (8.3%), omega-3 supplements – 47 (22.8%), proton pump inhibitors (PPIs) – 36 (17.5%), aspirin – 11 (5.3%), clopidogrel – 5 (2.4%), non-steroidal anti-inflammatory drugs (NSAIDs) – 26 (12.6%), amiodarone – 37 (18.0%). Dabigatran users (57) with amiodarone – 6 (10.5%), omega-3 supplements – 13 (22.8%), PPIs – 15 (26.3%), spironolactone – 1 (1.8%), NSAIDSs – 5 (8.8%), aspirin – 3 (5.3%), clopidogrel 1 (1.8%). Rivaroxaban users (139) with SSRIs/SNRIs – 1 (0.7%), amiodarone – 33 (23.7%), omega- 3 supplements – 27 (19.4%), NSAIDs – 7 (5.0%), aspirin – 2 (1.4%), clopidogrel – 2 (1.4%), verapamil – 1 (0.7%). Statistically significant difference between the potential drug interactions were detected comparing direct oral anticoagulants to warfarin – for dabigatran compared to warfarin p= 0.032 and rivaroxaban compared to warfarin p=0.004.

Conclusion

More than half of the high-risk atrial fibrillation patients have a potential drug interaction risk (51.9%). There is a statistically significant difference comparing the frequencies of detected potential drug interactions, DOACs being superior to warfarin (dabigatran versus warfarin p=0.032 and rivaroxaban compared to warfarin – p=0.004).