Drug interactions between warfarin and antibiotics: An integrative review

Abstract

Introduction: Administering warfarin with antibiotics poses challenges due to the increased risk of hemorrhagic episodes. Objectives: Therefore, this study aimed to investigate the most frequent drug interactions between warfarin and antibiotics. Methodology: Searches were conducted in PubMed, Virtual Health Library (BVS), and the Scientific Electronic Library Online (Scielo) using the MeSH terms warfarin, drug interactions, and antibacterial agents. Articles published in English and Portuguese were considered, with no date restrictions. Drug interactions were classified according to drugs.com. Results: A total of 19 articles were included. 85 drug interactions were identified, with the most prevalent being between warfarin and β-lactam antibiotics (50%) and quinolones/fluoroquinolones (33%). Regarding classification, 41% of DIs were categorized as major and 53% as moderate. No drug interactions were found between warfarin and two antibiotics (2%, dirithromycin and cefonicid) on drugs.com, despite studies confirming the drug interaction. In addition to antibiotic use, it is known that coagulation levels during warfarin therapy can be influenced by factors such as patient adherence to treatment, diet, presence of infections, and use of multiple medications. Therefore, understanding the influence of antibiotics on warfarin metabolism is compromised. Conclusion: Hence, to ensure that anticoagulant and antibiotic therapy is effective and safe for patients, it is crucial to develop supervision and monitoring strategies. Additionally, further studies are fundamental to deepen the understanding of antibiotics' interference in the metabolic pathway of warfarin.

Keywords: Warfarin; Drug Interactions; Antibiotics.