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Anticoagulation - oral - Management
How is anticoagulation treatment initiated?
- Anticoagulants are usually initiated in secondary care, a dedicated clinic in a hospital, or an outreach clinic in primary care.
- Where rapid anticoagulation is required:
- Warfarin is usually started with a loading dose of 10 mg.
- Subsequent doses depend up the prothrombin time reported as international normalized ratio (INR).
- For people older than 60 years of age, those with liver disease or cardiac failure, or those at high risk of bleeding, regimens that start with warfarin 5 mg doses, or a single 10 mg dose followed by 5 mg doses, may be preferable.
- It takes 48 to 72 hours for the anticoagulant effect of warfarin to fully develop.
- If an immediate effect is required (for example deep venous thrombosis or a pulmonary embolism) heparin is given concomitantly. This is done in secondary care.
- For people with with atrial fibrillation:
- There is no need to achieve anticoagulation rapidly; a slow loading regimen is safe and achieves therapeutic coagulation in the majority of people within 3–4 weeks.
- Warfarin 2 or 3 mg each day is generally an acceptable starting dose.
- A low starting dose is often more suitable for elderly people and people at high risk of bleeding.
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