How to manage a patient with an elevated INR of 2.40 on warfarin?

From the Guidelines

For a patient with an INR of 2.40 on warfarin, no immediate action is typically required if this is within or close to their target therapeutic range, and the current warfarin dose should be continued with regular INR monitoring as scheduled. Most patients on warfarin for conditions like atrial fibrillation or venous thromboembolism have a target INR of 2.0-3.0, making 2.40 appropriate 1. If the patient's target range is lower (1.5-2.0, as sometimes used for mechanical heart valves), consider a small dose reduction of 5-10% of the weekly warfarin dose. Monitor for any signs of bleeding such as unusual bruising, nosebleeds, blood in urine or stool, or excessive menstrual bleeding. Remind the patient to maintain consistent vitamin K intake through diet, as fluctuations can affect INR stability. Warfarin works by inhibiting vitamin K-dependent clotting factors, and an INR of 2.40 indicates moderate anticoagulation that balances stroke prevention with bleeding risk for most indications.

Some key considerations for managing patients on warfarin include:

• The risk of bleeding increases when the INR exceeds 4, and the risk rises sharply with values above 5 1.
• For patients with an INR between 5 and 9 and no bleeding or risk factors for bleeding, omitting the next 1 or 2 doses of warfarin and reinstating at a lower dose when the INR falls into the therapeutic range is a reasonable approach 1.
• Vitamin K1 can be administered orally in a dose of 1 to 2.5 mg to lower the INR quickly without causing resistance once warfarin is reinstated 1.
• Recent guidelines suggest that for perioperative management, the decision to interrupt anticoagulation should be based on the patient's thrombotic and bleeding risks, with a preference for time-based interruption of anticoagulation whenever possible 1.

Given the patient's INR of 2.40, which is within the therapeutic range for most indications, continuing the current warfarin dose and monitoring INR levels regularly is the most appropriate course of action, unless the patient is experiencing signs of bleeding or has a condition that requires a different target INR range 1.

From the FDA Drug Label

The dose of warfarin should be adjusted to maintain a target INR of 2.5 (INR range, 2.0 to 3.0) for all treatment durations. The patient's current INR of 2.40 is within the recommended range of 2.0 to 3.0.

• No adjustment to the warfarin dose is necessary at this time. 2

From the Research

Patient Management with Elevated INR

The patient has a protime of 28.6 and an INR of 2.40 while on warfarin. To manage this patient, the following steps can be considered:

• The patient's INR is slightly elevated, but not significantly high to warrant immediate reversal of anticoagulation 3.
• The risk of bleeding increases dramatically when the INR exceeds 4.0-6.0, although the absolute risk of bleeding remains fairly low, <5.5 per 1000 per day 3.
• Patient characteristics, including advanced age, treated hypertension, history of stroke, and concomitant use of various drugs, affect the risk of bleeding 3.

Treatment Options

• For reversal of excessive anticoagulation by warfarin, AVK withdrawal, oral or parenteral vitamin K administration, prothrombin complex or fresh frozen plasma may be used, depending on the excess of anticoagulation, the existence and site of active bleeding, patient characteristics and the indication for AVK 3.
• A dose of 1-2.5mg of oral phytomenadione (vitamin K(1)), reduces the range of INR from 5.0-9.0 to 2.0-5.0 within 24-48 hours 3.
• The use of home testing devices to measure INR has been suggested as a potential way to improve the comfort and compliance of the patients and their families, the frequency of monitoring and, finally, the management and safety of long-term oral anticoagulation 4.

Monitoring and Adjustment

• Periodic laboratory testing of international normalized ratio (INR) and a subsequent dose adjustment are therefore mandatory 4.
• The recommended therapeutic range for the INR for oral anticoagulant treatment of most conditions is 2.0 to 3.0 5.
• Overlap treatment with heparin and warfarin for 4 or 5 days is recommended 5.
• The concurrent use of certain drugs or presence of comorbid conditions can predispose to hemorrhagic complications of anticoagulant therapy 5.