The Southern Medical Journal (SMJ) is the official, peer-reviewed journal of the Southern Medical Association. It has a multidisciplinary and inter-professional focus that covers a broad range of topics relevant to physicians and other healthcare specialists.

SMJ // Article

Review Article

Preventing Warfarin-related Bleeding

Authors: Jeffrey James Glasheen, MD

Abstract

Warfarin is one of the most common anticoagulants in current use. It maintains a narrow therapeutic index resulting in a significant amount of bleeding. Changes in concomitant medication use and acute illnesses are common causes of overanticoagulation. Monitoring regimens based on patient characteristics and the intensity and duration of anticoagulant therapy, along with simple prediction rules, can reduce the risk of warfarin-related bleeding. Supratherapeutic international normalized ratios are usually best treated by holding a dose and/or reducing the weekly dose of warfarin. Patients with acute bleeding require more urgent warfarin reversal.


Key Points


* Patient characteristics such as age and history of bleeding as well as the intensity and duration of warfarin therapy are the strongest predictors of warfarin-related bleeding.


* Antibiotics, antiepileptics, and cardiac medications are the most common drugs to interact with warfarin.


* Simple rules can reliably predict a patient’s risk of bleeding while using warfarin.


* Supratherapeutic international normalized ratios in a nonbleeding patient are usually best treated by holding the warfarin and subsequently reducing the weekly dose.

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