Now, warfarin, you may have heard this called
Coumadin, has this really bizarre beginning.
They originally discovered when cattle were
just bleeding out after eating spoiled clover.
So you take some horrible event in nature,
and some very clever people figured out
how to turn spoiled clover into warfarin.
Now, it's still used today as rat poison.
Isn't that interesting?
Like, I've actually taken
this medication, obviously,
in a much smaller dose than
rat poison by body weight,
but we use it in clinical applications, too.
So, warfarin, originally founded
because cows were dying,
there were bleeding out after
eating spoiled clover,
and we use it for rat poison still today,
and we can give it to you as a medicine.
It's kind of scary sometimes
where things come from.
So, warfarin stops the
activation of vitamin K,
so there's less biosynthesis of the 4
vitamin K-dependent clotting factors.
Okay, that is an important point.
I want to make sure that you get that.
4 of your vitamin K clotting factors are big
players in your ability to make a clot.
So, the drug warfarin stops these
4 factors from being activated,
therefore, you don't make as many clots.
So, it decreases the production
of these factors by 30%-50%.
So somebody on warfarin has 30%-50% less
ability to use these 4 clotting factors.
Now, it doesn't impact the clotting factors
that are already circulating, right?
So it's just the ones as they're being made.
That's why you don't completely bleed
out for taking just a dose of warfarin.
So, remember, warfarin hits the clotting
factors as they're being made,
and it stops the activation of
the vitamin K-dependent ones.
So we don't use warfarin in emergency.
If someone came into ER and they're having an MI
from a big clot, warfarin is not our drug of choice.
We would use something --
after making sure the patient was safe, we
would use something like a thrombolytic,
a clot buster, if it was appropriate.
But warfarin, think of it as long-term
treatment, not for emergencies.
It may take several days to reach
therapeutic and anticoagulant levels.
So remember, when I was in the
hospital for a pulmonary embolism,
I got heparin right away in the hospital,
and then I started warfarin a few
days before I was discharged.
But I went home on both;
low-molecular-weight heparin and warfarin,
until my lab values for the warfarin
reached a therapeutic level.
Lab values for warfarin are PT and INR.
So you take this as a pill, that's a lot easier,
and it doesn't burn like fire like
We watch that PT/INR lab work, and they'll adjust
the dosage based on what results they get.
So when you're on warfarin, initially, as they're
trying to get you to a therapeutic level,
you'll have the test done really regularly.
Then it'll get to be longer
and longer periods of time,
the more stable and therapeutic
your PT/INR stays.
So, you can actually monitor your INR at home.
So we put a little monitor up there
for you to see what it looks like.
So patients can even do this.
So, I don't necessarily have to always go into the
lab once I'm established at a therapeutic level,
and I'm not having any problems.
The health care provider --
and I'm very compliant --
the health care provider may feel very
comfortable with me checking my INR at home,
much like diabetic patients
check their glucose.
Now, I want you to understand that PT/INR test
because nurses need to understand the
goals that we use lab to help us reach.
So a therapeutic level and
length of treatment will vary.
So, first of all, if a normal INR for
someone receiving warfarin is 1.0.
-- So that's someone not receiving warfarin.
That's where we start before they get it.
The health care provider will decide
what's the therapeutic level?
What are we going for?
But if somebody is on warfarin, that level has to
be higher than 1.0 because normally you're a 1.0,
we want that to be elevated because we
want you to be less likely to make clots.
So, I'm going to show you
an example of a protocol.
Every healthcare provider will have their
own exact protocol that they like to use
based on that patient's history and
their status and their lab work.
But let's just walk through
an example just for fun.
Okay, so it was my first episode of a
DVT, we don't know what caused it.
That's what idiopathic is,
makes us sound way smarter.
It just means, "Hey, we have no
idea why that happened to you."
So let's say we have a client who has a DVT, a
deep vein thrombosis, that would be in their leg.
It's their first episode and it's idiopathic.
We don't know what caused it.
What's our target INR?
Well, normal INR is 1.0, but because we want
you to be less likely to make more clots,
and we don't want this clot to get bigger,
we're going to shoot for 2.0-3.0.
So, how long are you going to
have to stay on this medication?
About 6-12 months.
Now, you may not even realize
right now, that is a pain in the --
I can't say it, all right?
That's a pain to be on that medication.
People don't like taking medication.
It's really not that problematic, except
for there are serious diet modifications.
We'll talk about those in a minute, but just
know that 6-12 months is nothing to sneeze at.
That's going to impact their life.
So DVT, first episode, normal
PT/INR or a normal INR is 1.0.
We're going to shoot for 2.0-3.0.
So you're going to be that
much higher than normal,
because we don't want that clot to get
bigger or you to make any more clots.
Now into a bigger problem,
a pulmonary embolism.
The target INR is the same, 2.0-3.0,
and at least 6-12 months.
That was a very long year for me.
I hated dealing with that, but
I should be very thankful
that my PE had a different
ending than my first patient.
Now, finally, patients who are on
prosthetic or aortic heart valves,
we want them a little bit higher.
Look, they go 2.5-3.5, and you may also
consider adding aspirin on to that.
They'll likely be on that
for the rest of their life
because some of those heart valves
are really prone to developing clots,
and that's why the patient would
be on it for the rest of their life.
Okay, so say you're my nurse and
we're starting this warfarin.
And let's say that I'm in for a pulmonary embolus,
right, and because that's what I was.
You look at my INR and it is 1.8.
What should you do?
Well, is it safe for you to give
the next dose of the medication?
Well, the target the healthcare providers
told me is 2.0 to 3.0, and I'm at 1.8.
That is lower than what our target was, so
absolutely, it's safe to give the next dose,
but you should contact the health care provider
and let them know where you are in the process.
Now, when you're actually practicing,
you'll know how they want to be notified,
but it is perfectly safe to give that medication.
Let's take another example.
If I'm in for a pulmonary embolism, you don't
know why it happened, now my INR is 4.5.
Should you give the medication?
No, because, look, my goal was 2.0 to 3.0, I'm at 4.5.
You should absolutely hold that medication
and contact the healthcare
Now I'm a big risk for bleeding in very
inappropriate and very dangerous places.
See, that's how nurses use evaluating
the effectiveness of medication therapy
by comparing it to lab results.
Now, when I told you it was inconvenient, I
used to have a lot more risk factors for clots.
I was carrying a lot more weight,
I was a lot more immobile,
and so, I ended up being on
Coumadin for over a year.
So, you know when you have a major health event,
you want to get healthy, but here's the problem.
Vitamin K is the antidote to Coumadin.
If like -- when I was at 4.5, you would have
been giving me vitamin K as the antidote
to bring that INR back down to under 3.0.
But as a patient, you have to keep in mind that
there's lots of foods that contain vitamin K.
So, I went through this major life event,
I'm like, "I'm going to eat healthier."
Well, look at your screen.
Everything that's on that screen is
healthy and it contains Vitamin K.
So, you have to educate patients that vitamin
K is in foods they would never suspect.
It made eating out really difficult.
It made planning my lunch very difficult.
And you couldn't just sit down and eat
a salad because that's really high --
green leafy things are very high in vitamin K.
So it was a radical life change for me.
I had to learn what foods had vitamin K.
We had to severely limit the foods with vitamin K.
That is not as easy as it sounds.
And in fact, when I teach these
classes, a lot of times,
I'll have students actually plan 1 day and follow
a low vitamin K diet or a low sodium diet,
so we can have empathy for our patients
that what we're telling them they
need to do is not that easy.
Now, if your patient is like, "I am
very committed to a kale salad.
I must have one."
Well, here's what we can do.
They're going to have to eat that kale
salad same size, same time of day,
every day for the treatment time.
So that means if you want that
kale salad at lunch every day,
then you're going to have to eat
a kale salad at lunch every day,
and the same size, and around the same time,
because they're going to base your
Coumadin dosage, your warfarin dosage,
on that you intake that much vitamin K every day.
So, if suddenly people become less committed
to absolutely having to have something
because it really impacts our therapeutic plan.
Also know that most people are resistant to this.
They're not going to follow the diet plan
as well as is in their best interest.
So, be patient, be kind, don't be judgmental,
but make sure you show them a list of
all the foods that have vitamin K,
and the weird ones that they may not expect,
so they can at least make an
educated and informed guess.
Now, if I had a patient, like I told you --
if my INR was 4.5, then what you
would give me is vitamin K.
It reverses the anticoagulant
effects of warfarin.
It's why you can't eat a lot of it in your diet,
and it helps those 4 vitamin
K-dependent clotting factors.
But it takes about 24 hours
to have the maximum effect.
So, usually, taking vitamin K oral
dose is the safest route to do that.
That doesn't mean, as nurses, we
wheel a giant salad into their room.
We'll actually give them oral
vitamin K as a medication.
Now, part of being good nurses is we always
want to know who shouldn't take a medication
or who is it unsafe for for
them to take the medication?
If someone is currently severely bleeding,
we don't want to give them warfarin.
If they're not very compliant
with the medication,
or they don't follow up with monitoring,
or they don't follow their dietary restrictions,
we might have to try and look for a better plan.
I'm not saying it would be as effective, but
we might need to look for another plan.
And there are some other
medications we could use
to have similar impact on the patient's body,
but they're usually a lot more expensive,
and you'll see commercials for them on TV.
Pregnant women also should not take warfarin.
Okay, so, who shouldn't take it?
Someone who's already bleeding,
someone who's going to have a difficult time
following the medication or the diet plan,
or someone who's pregnant.
Now, your job is to think back through those lists
and make sure you can
answer why should someone
who's currently severely bleeding not take
warfarin, and don't let yourself off the hook.
Don't just say, "Because they'll bleed more."
Think through that what warfarin does, and the
why you wouldn't want someone to be on it.
Work through the other 2 answers
as you pause the video.
Okay, now let's continue
to work through the people
who it's not really safe for them to take warfarin.
Uncontrolled hypertension or someone with
severe liver disease is also not safe for this.
Uncontrolled hypertension, that means
they've had hypertension that hasn't
been treated with medications,
it's been out of control, they may be at risk
for bleeding in a really inappropriate part.
Now, severe liver disease, remember those
clotting factors and where they're built?
Okay, so if they already have liver disease,
their clotting factors are
going to be way out of whack.
Warfarin is going to make that worse.
If they've had recent surgery, particularly
on their central nervous system,
their spinal column, or in their eye,
we don't want to risk bleeding there,
because there's the tiniest margin
for bleeding in those areas.
So if they've had recent surgery, we're going
to stop the warfarin before they have it,
and we're going to stop it for a
long period of time afterwards.
So then, if they are on any other medications
that increase the risk of bleeding with
Coumadin, including over-the-counter drugs.
So when I was taking warfarin, if I had a headache,
I couldn't take aspirin, I couldn't take Tylenol,
which I was not really a fan of anyway, and
I couldn't even take my good friend NSAIDs.
So while you're on warfarin, you don't
want to take any of these regular,
over-the-counter medications without really
running it through your health care provider.
But you think about that every time you
have a headache, or an ache, or a pain
and it seems like some joint in my body
is always complaining at some point,
you can't use what we normally would:
aspirin, acetaminophen, or an NSAID.
But special note to that is remember,
heparin may be used with Coumadin
until the Coumadin reaches
those therapeutic levels.
I went home on low-molecular-weight
heparin, the shots in my abdomen,
and Coumadin until my PT/INR was at a normal level.