In case you missed it the newest anticoagulation agent has hit Australia – dabigatran (Pradaxa™). It is currently on the PBS for just two indications – but watch that space…
- Anticoagulation of patients with non-valvular AF – where you would use warfarin usually
- For thromboprophylaxis in knee or hip replacement – where you might use enoxaparin (Clexane™)
When I started trying to incorporate this new drug into my limited brain, I tried to think of it as a warfarin substitute – but apart from being oral admin, it really is not like warfarin. I have found it far more useful to think of it as “clexane you can swallow”, here is why..
- It works way down the clotting cascade – a direct thrombin inhibitor, close to heparin’s antithrombin inhibition in terms of site of action in the Coagulation cascade
- Relatively short duration of action – you need to take it BD to get 24 hr cover – like BD clexane, and its effects are gone by 12 hours in normal patients
- It is renally excreted and requires renal dose adjustment – there is no need to adjust for liver disease.
- You can’t really reverse it, you might be sorta, kinda reduce the effect with factor VIIa ($$$$) or dialysis, but waiting 12 hours might be your best option (actually if it is less than 2 hours since swallowed you can try charcoal)
- You don’t need to monitor – so easier to get the dose right, you just need to know the patients renal function to dose correctly
- If you want to know the “effect” you can measure a few obscure clotting times (Thrombin time) but this is not really possible in most centres. hOwever, if you do an APTT – and the time is low / normal, then you can be assured the patient is not significantly anticoagulated.
All you really need to know about dabigatran in one place – Check out the UNC review. This includes simple guidelines and management of patients in the perioperative period for the Anaesthetic clinic.
You can also check out the eMJA article that accompanied its release in 2010.
For those of us in remote areas I reckon this drug is a bit of a double-edged sword. Sure it is easier to use than warfarin, no monitoring etc…. but if you get a brain bleed in the middle of nowhere you have no good options to turn it off or even measure the effects,
Comments or questions welcome.
Oh, and I reckon it needs a witty new nickname – so we can all remember it – dabigatran is just too hard. Suggestions?