Volume : 13, Issue : 06, June – 2026
Title:
WARFARIN TOXICITY DUE TO DRUG INTERACTION: EARLY RECOGNITION AND SUCCESSFUL MANAGEMENT OF A CASE
Authors :
Vasanth kumar K, Dr. P. Maheshwari, Dr. Karthickeyan krishnan, Dr. P. Shanmugasundaram
Abstract :
Background: Warfarin is an commonly prescribed oral anticoagulant with a narrow therapeutic index and potential for many drug interactions. Many interacting medications, if taken concurrently with warfarin, may increase prothrombin time and International Normalized Ratio (INR), leading to potentially dangerous bleeding complications. Metronidazole is one such drug that has been found to inhibit the metabolism of warfarin.
Case Presentation: A 60 year old female with atrial fibrillation, being on long-term Warfarin therapy, presents with ecchymoses, gum bleeds,hematuria and generalized weakness and fatigue after the initiation of metronidazole. Lab values show very high prothrombin time and greatly elevated INR of 8.6 which confirmswarfarin intoxication. The medication Warfarin and the suspected inciting agent metronidazole were discontinued immediately. The patient was treated with vitamin K intravenous and was under close observation and eventually INR normalized with complete resolution of bleeding without significant sequelae, the patient was then rechallenged with warfarin on a lower dose.
Conclusion: This case reinforces the clinical importance of warfarin-metronidazole interaction and underlines the necessity for careful review of all medications, patient education and frequent monitoring of INR values.
Keywords: Warfarin, Metronidazole, Drug Interaction, Warfarin Toxicity, International Normalized Ratio, Bleeding, Anticoagulatio
Cite This Article:
Please cite this article in press Vasanth kumar K et al., Warfarin Toxicity Due To Drug Interaction: Early Recognition And Successful Management Of A Case, Indo Am. J. P. Sci, 2026; 13(06).
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