Unfractionated heparin

Unfractionated heparin is a very widely used and inexpensive parenteral anticoagulant with a narrow therapeutic window, which makes careful monitoring necessary. Common indications are acute coronary syndromes with or without ST-segment elevation, percutaneous coronary intervention, early treatment of venous thromboembolism, and bridging therapy for interrupted oral anticoagulation. Bleeding is its most common side effect followed by thrombocytopenia and osteoporosis, the latter of which is only seen with longer periods of treatment.