There are two main types - unfractionated (UFH) and low molecular weight Heparin (LMWH)
About: Always check the BNF or equivalent for prescribing advice
- Used both in treatment and prevention of thrombosis
- A collection of polysaccharides derived from porcine gastric mucosa
- Unfractionated: composed of a mixture of naturally occurring glycosaminoglycans with polysaccharide chains. The molecular weight varies from 5,000-30,000. It is normally given IV and can be reversed by stopping the infusion and giving protamine.
- Low Molecular weight Heparin is made from unfractionated: composed of a mixture of naturally occurring glycosaminoglycans with polysaccharide chains. The molecular weight varies from 4,000-6,500. It is much more difficult to reverse with a longer half-life.
- Thrombocytopenia, haemophilias, liver failure, renal failure
- Systolic >200 mm Hg or diastolic >120 mm Hg
- Active peptic ulcer, oesophageal varices
- Aneurysm, proliferative retinopathy, recent organ biopsy
- Recent trauma or surgery to head, orbit, spine, recent stroke
- Confirmed intracranial or intraspinal bleed
- History of Heparin-induced thrombocytopenia or thrombosis
- All Heparins work by binding to Antithrombin III which deactivates thrombin and so clotting. Mainly anti-Xa activity
- Low molecular weight Heparins also enhance anti-IIa activity
Management of side effects
- Bleeding - give protamine, transfuse
- Heparin induced thrombocytopenia: Seen in 5% which is more common the longer treatment duration. Stop all Heparins and seek haematology advice.
- Osteoporosis with long term use.
- With significant concern about bleeding speak to haematology.