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Offline DoctorBeaver

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How does warfarin work?
« on: 30/09/2008 22:08:09 »
Right, so I've got idiots clots on my lungs and I've been put on warfarin to thin my blood. But how does it do that?  ???


 

Offline Evie

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How does warfarin work?
« Reply #1 on: 30/09/2008 22:30:34 »
It prevents your blood from clotting.

Here's a Wiki article that goes into much more detail. http://en.wikipedia.org/wiki/Blood_coagulation

The coagulation cascade of secondary hemostasis has two pathways, the contact activation pathway (formerly known as the intrinsic pathway) and the tissue factor pathway (formerly known as the extrinsic pathway) that lead to fibrin formation. It was previously thought that the coagulation cascade consisted of two pathways of equal importance joined to a common pathway. It is now known that the primary pathway for the initiation of blood coagulation is the tissue factor pathway. The pathways are a series of reactions, in which a zymogen (inactive enzyme precursor) of a serine protease and its glycoprotein co-factor are activated to become active components that then catalyze the next reaction in the cascade, ultimately resulting in cross-linked fibrin. Coagulation factors are generally indicated by Roman numerals, with a lowercase a appended to indicate an active form.

The coagulation factors are generally serine proteases (enzymes). There are some exceptions. For example, FVIII and FV are glycoproteins and Factor XIII is a transglutaminase. Serine proteases act by cleaving other proteins at specific sites. The coagulation factors circulate as inactive zymogens.

The coagulation cascade is classically divided into three pathways. The tissue factor and contact activation pathways both activate the "final common pathway" of factor X, thrombin and fibrin.



Warfarin affects the vitamin K dependent clotting factors (II, VII, IX,X) , while heparin and related compounds increase the action of antithrombin on thrombin and factor Xa.
« Last Edit: 30/09/2008 22:34:37 by Evie »
 

Offline RD

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How does warfarin work?
« Reply #2 on: 30/09/2008 23:25:30 »
You now have a good excuse to refuse extra helpings of broccoli...
Quote
patients taking warfarin should watch their intake of vitamin K, since too much vitamin K may alter the way in which warfarin works. The amount of foods high in vitamin K (such as broccoli, spinach, and turnip greens) eaten each week should be kept stable. Grapefruit juice should be avoided because it may intensify the effects of this medication.
http://www.answers.com/topic/warfarin


Now the bad news...
Quote
Alcohol should also be avoided while taking warfarin because it interferes with warfarin's effectiveness.
http://www.answers.com/topic/warfarin


Aren't Beavers rodents ?
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Dictionary: warfarin  (wr'fər-ĭn) n. A white crystalline compound, C19H16O4, used as a rodenticide and as an anticoagulant.
http://www.answers.com/topic/warfarin
« Last Edit: 30/09/2008 23:36:42 by RD »
 

Offline DoctorBeaver

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How does warfarin work?
« Reply #3 on: 04/10/2008 11:45:52 »
Sam - thanks for your reply. I already know what it's used for but others may not.

Evie - what's that in English?  ???
 

Offline rosalind dna

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How does warfarin work?
« Reply #4 on: 04/10/2008 14:37:36 »
Hi Doc but Warfarin is also Rat poison and makes their systems bleed to death btw no tears lost for them in Rosalind. long story
 

Offline iko

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How does warfarin work?
« Reply #5 on: 04/10/2008 15:15:03 »
Every effective drug is also a poison.
It's a matter of doses.
Rat poison doesn't mean toxic for beavers too!  ;D
New drugs are coming, to take the 'old' warfarin-coumadin's place.
I hope soon

ikod
« Last Edit: 04/10/2008 15:16:53 by iko »
 

Offline DoctorBeaver

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How does warfarin work?
« Reply #6 on: 04/10/2008 15:41:56 »
Warfarin is a pain in the butt; having to have a blood test every damned week  [:(!]
 

Offline rosalind dna

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How does warfarin work?
« Reply #7 on: 04/10/2008 16:09:31 »
Warfarin is a pain in the butt; having to have a blood test every damned week  [:(!]

I don't want the Warfarin to be poisonous to Beaver and surely it's better to have weekly blood tests than be in hospital, Doc?
 

Offline RD

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How does warfarin work?
« Reply #8 on: 04/10/2008 18:22:55 »
Warfarin is a pain in the butt; having to have a blood test every damned week  [:(!]

There are alternatives to warfarin which do not require such frequent monitoring...

Quote
Currently, the only orally available anticoagulants are the vitamin K antagonists, such as warfarin. LMWH and fondaparinux have simplified the initial treatment of VTE[Venous ThromboEmbolism]. Both agents have better bioavailability after subcutaneous injection and a longer half-life than heparin. In addition, they produce a more predictable anticoagulant response. These features permit once daily subcutaneous dosing without coagulation monitoring. Consequently, the majority of patients with VTE can now be treated with LMWH or fondaparinux as outpatients, an approach that reduces healthcare costs and enhances patient satisfaction.
http://atvb.ahajournals.org/cgi/reprint/28/3/380

Now the bad news: they have to be injected daily / weekly: literally a pain in the butt.

 

Offline DoctorBeaver

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How does warfarin work?
« Reply #9 on: 05/10/2008 11:44:03 »
RD - it would still involve a weekly trip to the doctor to have a needle stuck in me, so what's the difference?
 

Offline Andrew K Fletcher

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How does warfarin work?
« Reply #10 on: 05/10/2008 17:26:34 »
Eth sorry to hear about the recent problem with your lungs. Hope all goes well for you and wishing you a speedy recovery. It may interest you to know that drinking distilled water, taking garlic 2 times a day reduces the bloods ability to clot, without warfarin. And tilting your bloody bed will help loads too :P
 

Offline RD

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How does warfarin work?
« Reply #11 on: 06/10/2008 02:57:42 »
RD - it would still involve a weekly trip to the doctor to have a needle stuck in me, so what's the difference?

It's a subcutaneous injection, (not intravenous), you would inject yourself (daily), so no weekly trip to the doctor.
The injected anticoagulant works in a different way from Warfarin and requires less frequent coagulation monitoring.
 

There are new oral anticoagulants being developed which do not require frequent (weekly) monitoring...

Quote
The difficulties surrounding warfarin administration have spurred the development of new oral anticoagulants that can be given in fixed doses with little or no coagulation monitoring.
http://atvb.ahajournals.org/cgi/reprint/28/3/380

When these new oral anticoagulants come to market you may be spared your metaphorical or literal "pain in the butt",
 (if your health-care-provider considers them to be cost-effective).
 

Offline DoctorBeaver

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How does warfarin work?
« Reply #12 on: 06/10/2008 12:03:27 »
When I was in hospital I was having daily Heparin injections in my tummy. That smarted a bit  :(
 

Offline DoctorBeaver

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How does warfarin work?
« Reply #13 on: 06/10/2008 12:03:49 »
Andrew - thank you for your kind wishes.
 

Offline time-cop

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How does warfarin work?
« Reply #14 on: 09/10/2008 20:40:20 »
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When I was in hospital I was having daily Heparin injections in my tummy

Blimey boss, you got the old memory going again, only with me they had the size of a footie pitch to choose from ! ;D
 

Offline DoctorBeaver

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How does warfarin work?
« Reply #15 on: 10/10/2008 05:51:14 »
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When I was in hospital I was having daily Heparin injections in my tummy

Blimey boss, you got the old memory going again, only with me they had the size of a footie pitch to choose from ! ;D

 

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How does warfarin work?
« Reply #15 on: 10/10/2008 05:51:14 »

 

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