Indication	Treatment
Primary prophylaxis
Any surgery	Unfractionated heparin subcutaneously 5000 IU three times daily
Malignancy or orthopaedic surgery	Unfractionated heparin subcutaneously 5000 IU three times daily, possibly with replacement of deficient factors
Pregnancy	Unfractionated heparin subcutaneously 5000 IU three times daily
Pregnancy in antithrombin III deficiency	Therapeutic dose of unfractionated heparin to prolong APTT or dose adjusted warfarin (INR 2.0-3.0), except during first trimester and latter part of third trimester, when unfractionated heparin is used
Puerperium (for 4-6 weeks)	Unfractionated heparin subcutaneously 5000 IU three times daily or dose adjusted warfarin (INR 2.0-3.0)
Secondary prophylaxis
First episode of thrombosis	Dose adjusted warfarin for 6 months
First episode of life threatening thrombosis, multiple deficiencies, continuing predisposing factor	Lifelong oral anticoagulation
Recurrent thrombosis	Lifelong oral anticoagulation
Treatment of established thrombosis
Treatment of acute thrombosis	Unfractionated heparin to prolong APTT followed by oral anticoagulation treatment, possibly with replacement of the deficient factors