Major bleeding precipitated by interactions between antibiotics and warfarin: a case series

Major bleeding precipitated by interactions between antibiotics and warfarin: a case series

Luana Marchesan1, Raíssa Londero Chemello1, Vanessa Thomé1, Diego Chemello1,2

1.Department of Clinical Medicine, Health Science Center, Federal University of Santa Maria, Santa Maria, Brazil
2.Postgraduate Program in Health Science, Federal University of Santa Maria, Santa Maria, Brazil

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Warfarin is a widely used anticoagulant agent with a large spectrum of indications for prevention and treatment of thromboembolic complications. Despite its low cost, warfarin and all other vitamin K antagonist (VKA) use has several limitations, including narrow therapeutic index requiring frequent laboratory monitoring to prevent complications related to under- and over-anticoagulation. The concomitant use of medications may alter the metabolism of warfarin by inducing or inhibiting the cytochrome P450-2C9, resulting in a decrease or increase in anticoagulant effect. In this setting, interactions between warfarin and antibiotics have been described. These interactions represent one of the problems with VKA use in the clinical setting. We aimed to report four cases where the prescription of antibiotics without proper control of anticoagulation levels led to major hemorrhagic complications.

Keywords: Anticoagulants; warfarin; drug interactions; hemorrhage; anti-bacterial agents

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How to cite this article:
Luana Marchesan, Raíssa Londero Chemello, Vanessa Thomé, Diego Chemello. Major bleeding precipitated by interactions between antibiotics and warfarin: a case series. International Journal of Case Reports, 2018 2:22. DOI: 10.28933/ijcr-2018-05-0701.

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