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Dabigatran – Clexane you can swallow

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…

  1. Anticoagulation of patients with non-valvular AF – where you would use warfarin usually
  2. 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?

Comments

  1. Minh Le Cong says:

    thanks Casey for this update. I have been telling all my colleagues to keep an eye out for dabigatran. Once it gets PBS approval, I reckon it will be the death knell of warfarin as we know it.

    the issue of emergency reversal I agree is an issue. but then again hopefully with dabigatran we will not see the need as often.

    nice analogy “oral clexane” ..might borrow that one thankyou!

  2. Hi Casey,

    Hmm, I think you were thinking of Rivaroxaban, a competive inhibitor of activated factor Xa when you came up with ‘oral clexane’. Da Big Train (say it with a badass Italian accent) is more like *oral heparin* with it’s affect on thrombin. 😉
    Both are PBS listed (rivaroxaban has the jaunty sounding Xarelto for a brand name – what is it with ‘X’s in the brand names??), but only Da Big Train has the precious listing for AF – both drugs have comparable evidence in this area though, that is; non-inferiority with warfarin. It will be interesting to see which one wins in the long term, certainly, I’d have to agree that warfarin is finally on the way out. Yeehaa.

  3. And a correction – Dabigatran is not yet PBS listed for AF – it was approved by the PBAC but hasn’t got past cabinet as yet.

  4. Casey Parker says:

    Thanks Roy (aka da blog Police) nothing gets past you – maybe you should be on the TGA?

    I understand the company has made dabi available to Australian AF patients via a scheme where each GP is allowed a certain number of patients to do a trial on for free. Very clever move. This is akin to pimps getting the hos hooked on crack, in terms of marketing!
    C

  5. really nice analogy of ‘oral clexane’…

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