Warfarin in the Emergency Service: Drug Interactions and Clinical Considerations

Abstract

Aim: Drug-drug interactions (DDIs) are common occurrences where one drug influences the blood concentrations or efficacy of another. Warfarin, known for its narrow therapeutic index, carries a heightened risk of severe drug interactions. Material and Methods: We retrospectively analyzed the records of 211 patients using warfarin at the Emergency Health Services clinic of Kırklareli Training and Research Hospital from January 1, 2020, to December 31, 2020. Patient demographics and drug regimens were documented, and drug interaction assessments were conducted using the drugs.com database. Results: Among the 211 patients, 17 exhibited signs of bleeding, including 5 with major bleeding and 12 with minor bleeding. Of these, 129 had INR values exceeding 2.5, while 82 had INR values below 2.5. Notably, 11 of the 17 bleeding patients had INR values above 2.5, with an average INR of 3.69. Analysis revealed that the 211 patients collectively used 111 different drugs, with an average of 3.81 drugs per prescription. Intriguingly, 33 of these drugs exhibited major, moderate, or minor inter-actions and were prescribed to 174 patients. Conclusion: In conclusion, cautious and selective prescription of medications is warranted for patients receiving warfarin due to the potential for significant drug interactions.