What are the follow-up instructions for a 76-year-old male with a history of Deep Vein Thrombosis (DVT) to the right great Saphenous vein, currently on warfarin (Coumadin) 5 mg and valsartan (Diovan) for hypertension, with an International Normalized Ratio (INR) of 2.4?

From the Guidelines

The patient should continue his current warfarin dose of 5 mg daily as his INR of 2.4 is within the therapeutic range for DVT treatment, and schedule a follow-up appointment with his healthcare provider in 4 weeks for INR monitoring, as recommended by the American Heart Association/American College of Cardiology Foundation guide to warfarin therapy 1. The patient's current INR of 2.4 is within the therapeutic range of 2.0-3.0, which is suitable for DVT treatment. According to the American Heart Association/American College of Cardiology Foundation guide to warfarin therapy 1, once the INR becomes stable, the frequency of testing can be reduced to intervals as long as 4 weeks.

• The patient should maintain regular INR monitoring every 4 weeks as long as his values remain stable.
• The valsartan (Diovan) for hypertension should also be continued at the current prescribed dose.
• The patient should be vigilant for any signs of bleeding such as blood in urine or stool, excessive bruising, or prolonged bleeding from cuts, which should prompt immediate medical attention.
• Additionally, he should watch for symptoms of recurrent DVT including leg pain, swelling, warmth, or redness.
• The patient should maintain consistent vitamin K intake through diet to avoid fluctuations in INR values and should inform all healthcare providers about his anticoagulation therapy before any procedures.
• Warfarin therapy for DVT typically continues for at least 3-6 months, but given his age and possibly recurrent nature of his condition, longer or indefinite therapy might be appropriate, which will be determined at his follow-up appointment based on his risk-benefit assessment 1.

From the FDA Drug Label

The dosage and administration of warfarin sodium tablets must be individualized for each patient according to the particular patient’s PT/INR response to the drug. For patients with a first episode of DVT or PE secondary to a transient (reversible) risk factor, treatment with warfarin for 3 months is recommended For patients with a first episode of idiopathic DVT or PE, warfarin is recommended for at least 6 to 12 months. 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 is 2.4, which is within the recommended range of 2.0 to 3.0.

• The patient should continue taking warfarin 5 mg as prescribed.
• The patient should have regular INR checks to ensure the INR remains within the target range.
• The patient should be advised to follow up with their healthcare provider in a few days to a week to recheck their INR and adjust their warfarin dose if necessary.
• The patient should also be advised to report any signs or symptoms of bleeding or thrombosis to their healthcare provider immediately. 2

From the Research

Patient Follow-up Instructions

The patient is a 76-year-old male with a history of Deep Vein Thrombosis (DVT) to the right great Saphenous vein, currently on warfarin 5 mg and valsartan for hypertension, with an International Normalized Ratio (INR) of 2.4. Based on the studies, the following instructions can be provided:

• The patient's current INR of 2.4 is within the desirable range of 2.0-3.0, as recommended by the Australasian Society of Thrombosis and Haemostasis 3.
• The patient should continue warfarin therapy for at least 3-6 months after the DVT, as recommended by the Australasian Society of Thrombosis and Haemostasis 3.
• For patients over 75 years, the target INR may be reduced to 2.0-2.5, as recommended by the Australasian Society of Thrombosis and Haemostasis 3.
• A study on Chinese patients with venous thromboembolism found that an INR range of 2.0-3.0 is optimal for preventing recurrent VTE, and that this range does not increase the risk of major bleeding 4.
• However, another study found that warfarin may contribute to the pathogenesis of cancer-associated venous limb gangrene by leading to severe depletion of protein C while failing to reduce thrombin generation, especially when the INR is supratherapeutic 5.
• The patient should be monitored regularly for signs of bleeding or thromboembolic events, and the warfarin dose should be adjusted as needed to maintain an INR within the target range.
• The patient should also be educated on the importance of adhering to the warfarin regimen and attending follow-up appointments to monitor their INR and adjust the dose as needed.

Key Considerations

• The patient's age and medical history should be taken into account when determining the target INR range and warfarin dose.
• The patient should be monitored regularly for signs of bleeding or thromboembolic events, and the warfarin dose should be adjusted as needed to maintain an INR within the target range.
• The patient should be educated on the importance of adhering to the warfarin regimen and attending follow-up appointments to monitor their INR and adjust the dose as needed.
• The patient's INR should be monitored closely, as bleeding can result in an elevated INR in patients previously stable on warfarin 6.

Follow-up Schedule

• The patient should have regular follow-up appointments to monitor their INR and adjust the warfarin dose as needed.
• The frequency of follow-up appointments will depend on the patient's individual needs and medical history.
• The patient should be instructed to contact their healthcare provider immediately if they experience any signs of bleeding or thromboembolic events.