Cengizhan Ceylan - Department of Clinical Pharmacy, Faculty of Pharmacy, Selcuk University, Konya, Turkey
Rashida Muhammad Umar - Department of Clinical Pharmacy, School of Pharmacy, İstanbul Medipol University, Istanbul, Turkey
Büşra Nur Çattık - Department of Clinical Pharmacy, School of Pharmacy, İstanbul Medipol University, Istanbul, Turkey
Fatih Bolel - Department of Clinical Pharmacy, School of Pharmacy, İstanbul Medipol University, Istanbul, Turkey

Background: Drug-drug interactions can often lead to preventable adverse drug events and hospitalization. However, the clinical outcome of a potential drug-drug interaction that may range from minor alterations to major toxicity or loss of effect is often unknown. Drugs with narrow therapeutic index are more susceptible to the outcomes of interactions. Anticoagulants are one of the drug groups prone to drug-drug interactions and have important side effects. in this retrospective study, the frequency of drug-drug interactions involving warfarin, heparin and enoxaparin was investigated. Methods: Overall, ۳۰۰ patients (including ۵۵% males with an average age of ۵۰.۷۵ years) participated in this study, and for each anticoagulant, ۱۰۰ patient orders were randomly selected from the hospital system. Drug-drug interactions were evaluated using the Micromedex drug interaction checker. Results: A total of ۱۶۹۱ drug-drug interactions (۳۰۶ major, ۲۵۳ moderate, and ۸۹ minor interactions) were recorded of which only ۶۴۸ (average ۲.۱۶) involved warfarin, heparin, or enoxaparin. Most interactions were recorded in patients admitted to the cardiovascular surgery (n=۳۱۲) and cardiology (n=۱۱۹) wards. There was a significant relationship between the number of drugs and the frequency of interaction. warfarin had the highest number of interactions (n=۳۸۸). Conclusion: The frequency of drug interactions is high in patients on anticoagulant therapy. The efficacy and safety of these drugs can be affected by drug interactions. Accordingly, these interactions should always be considered, especially in patients with multiple drug use. Efficient monitoring strategies should be employed to optimize treatment while reducing adverse effects.

Drug-drug interactions, Warfarin, Enoxaparin, Heparin