New Chest guideline & loading warfarin?

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sherlockRX

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The very first recommendation of new Chest guideline: "For patients sufficiently healthy to be treated as outpatients, we suggest initiating VKA therapy with warfarin 10 mg daily for the first 2 days followed by dosing based on international normalized ratio (INR) measurements rather than starting with the estimated maintenance dose."

So basically are we coming back to doing oral loading dose (10mg) of warfarin now? I thought this practice has been debunked in the past with a couple major studies compared between 5mg vs. 10mg warfarin that saw more risks with doing 10mg? How is it doing 10mg loading dose will get you to therapeutic INR level faster, if rate of metabolism of clotting factors doesn't depend on the size of warfarin's dose, I assume?

Just hope to stir discussion among PharmDs in light of the new Chest guideline which I'm sure will be a much-debated topic in these next couple months.
 
I saw that too and it rocked my world. avoiding loading warfarin was one of those things drilled into my head in pharm school. It's going to take me some time to adJust.
 
yeah, there are so many things changed that totally go against my belief built in pharmacy school. Like the newest FDA updates on statins' labels which include risk of hyperglycemia and regular LFTs are no longer recommended...😕
 
Saw that too and also found it strange since we just learned not to load warfarin on my ambulatory care rotation. Also different-no vitamin K for an INR up to 10 if the patient isn't bleeding.
 
I still don't think I agree. In my limited experience, we had a lot more difficulty getting stable INR's with patients who were loaded on 10mg.
 
Doesn't that create a hypercoagulable state? You deplete protein C within the first day, but the factors haven't fallen yet, iirc.
 
Add this to the fact that routine pharmacogenetic testing is not recommended prior to initiating therapy (and rightly so), but what about the ~15% of people with a CYP2C9*3 allele and the ~15% of people with VKORC1-AA haplotypes? Since we're not doing routine p'genetic testing, what's gonna happen when the person with *1*3 alleles and an AA haplotype gets 10 mg warfarin??? They're recommended to start at 0.5-2.0 mg. I just don't see this particular recommendation as being very prudent. I mean what's the harm of starting at 5 mg and working your way up if necessary?
 
Yea I read that and started shaking my head. This is the suck part about not having a more clinically facing job, I don't have the time or resources to read the studies (especially since I'm not a preceptor).

My "hey I should skim this" list is now probably longer then the reading list from the last rotation I did.
 
yeah, there are so many things changed that totally go against my belief built in pharmacy school. Like the newest FDA updates on statins' labels which include risk of hyperglycemia and regular LFTs are no longer recommended...😕

When I saw this the cynic in me immediately thought that it had something to do with drug company influence and the push to make statins OTC.
 
Yea I read that and started shaking my head. This is the suck part about not having a more clinically facing job, I don't have the time or resources to read the studies (especially since I'm not a preceptor).

My "hey I should skim this" list is now probably longer then the reading list from the last rotation I did.


Yeah, can somebody direct me to the study that this Chest based this particular recommendation on? I can only access to the executive summary, not the full edition, and I don't know which references that they used.
 
Yeah, can somebody direct me to the study that this Chest based this particular recommendation on? I can only access to the executive summary, not the full edition, and I don't know which references that they used.

Here's a link to the full version for that particular recommendation:
http://chestjournal.chestpubs.org/content/141/2_suppl/e152S.full
I'm not able to access it either, don't have a Chest login here. The rest of the studies should be sufficient, however. 👍
 
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