Warfarin (Coumadin) use

About Warfarin (Coumadin) use

Warfarin inhibits vitamin K dependent coagulation factors. It is used to thin the blood and is prescribed in the following conditions: heart arrhythmias (atrial fibrillation), stroke, heart stents, deep vein thrombosis (blood clot), pulmonary embolus (blood clot of the lung), mechanical heart valves, and hyper-coagulable disorders. The patient's blood is checked periodically to monitor the effectiveness of the medication. Dietary changes and new medications can alter the effects of the drug causing either too much or too little anti-coagulation.

Symptoms

Too much medication can cause: nosebleeds, bleeding gums, vomiting blood, vomiting coffee grounds, bloody stools, black stools (melena), easy bruising, dizziness, fainting, confusion.

Tests & Diagnostics

Blood tests are performed periodically to measure the Prothrombin Time (PT), which is converted to a value called the INR (International Normalized Ratio). The target INR range is usually between 2 and 3, although people with a mechanical heart valve or a hyper-coagulable state may need to run a higher INR.

Conventional treatment summary

The patient's blood is monitored to ensure the PT/INR is therapeutic. Patients with an INR above the target range are at increased risk of bleeding. Those with an INR below the target range are at risk of unwanted clotting. In both situations, more frequent monitoring is needed.

Medical specialties

Internal Medicine · Pediatrics · Family Practice · Hematology and Oncology · Pediatric Hematology and Oncology

This page is educational content, not medical advice. Always consult a qualified clinician for diagnosis and treatment of Warfarin (Coumadin) use.