Thursday, 1 May 2014

NOACs

There are two main NOACs (Noval Oral Anti-Coagulants) that we are seeing used now. They have limited indications, but these will increase as their trials continue:
- VTE prophylaxis following hip and knee replacement surgery - apixaban, dabigatran and rivaroxaban
- Prevention of stroke and systemic emboli in patients with non-valvular AF - apixaban, dabigatran and rivaroxaban
- Treatment of and secondary prevention of DVT and PE - rivaroxaban 

All of these NOACs work further along the clotting cascade than we are used to, which limits reversal options. 

Dabigatran:
Direct thrombin inhibitor
BD dosing with predictable pharmacokinetics, as no cytochrome p450 interaction. 
 


 
Rivaroxaban:  factor Xa inhibitor. Not as much information available - I think similar measures apply. 


Bleeding


   - stop Dabigatran
   - assess severity (if mild just skip a dose)
   - control source of haemorrhage
   - do coagulation screen (APTT, TT)
   - check time of last dose and discuss with Haematology
   - correct co-existant bleeding diathesis e.g. platelets if < 80
   - oral charcoal if ingested within 2 hours
   - haemodialysis (particularly if in renal failure) -> removes ~60% over 2-3 hours

References

http://guidance.nice.org.uk/TA261
http://www.enlightenme.org/knowledge-bank/journal-scan/dabigatran-review-pharmacology-and-management-bleeding-complications-nov
http://emcrit.org/misc/bleeding-patients-on-dabigatran/
http://lifeinthefastlane.com/education/ccc/dabigatran-and-bleeding/
http://emergencyeducation.net/1/category/critical%20care/1.html
http://www.thepoisonreview.com/2011/09/11/dabigatran-toxicity-the-top-10-questions/
http://www.thepoisonreview.com/2011/09/11/3304/
http://i0.wp.com/emcrit.org/wp-content/uploads/Hennepin-County-Dabigatran-Reversal.png

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