- low molecular weight heparin (AKA dalteparin/fragmin, enoxaparin/clexane, tinzaparin)
- unfractionated (AKA 'heparin')
So what are the differences?
- molecular weight
- LMW heparin, as the name suggests, has a lower molecular weight - 5000 compared to unfractionated heparin's 13000
- half life
- LMW heparin has a longer half life than unfractionated heparin
- mechanism of action
- LMW heparin inhibits factor Xa but has little effect on antithrombin
- unfractionated heparin binds antithrombin
- affect on aPTT
- LMW heparin has little effect on aPTT
- unfractionated heparin prolongs aPTT
- side effects
- both can cause osteoporosis and thrombocytopenia but the risks are greatest with unfractionated heparin
- reversibility
- unfractionated heparin can be fully reversed by protamine
- LMW heparin cannot be fully reversed by protamine
A side effect of protamine to be aware of is hypotension.
HIT (=heparin induced thrombocytopenia) is a potentially serious side effect of heparin use which will be covered tomorrow.
With that to look forward to lets shake on to the last battle of the day, essential tremor...
