So, let's break down the different routes.
We'll look at oral medications first.
Now, what about their rate
of time in the bloodstream?
And we'll look at each one of
the different types of routes
and talk about how long it takes
them to get into the bloodstream,
what's the impact of first pass effect, and the
same kind of variables as we walk through it.
So, when we say oral, we mean, that
could be a pill, a liquid, or a tablet,
but it doesn't include sublingual.
Sublingual is…right here,
underneath your tongue.
We use that for special medications for like
nitroglycerin for people having chest pain.
We can also use it for certain
medications for nausea,
which is brilliant, because it
works really, really rapidly.
But when we're talking about oral medications,
we're not talking about anything sublingual.
We're talking about pills, liquids, or tablets.
So far as how long it takes it
to get into the bloodstream,
oral routes are much longer than other routes,
because they've got to go through several other
steps before they make it to the bloodstream.
It's got to go through multiple steps in the GI
and then it finally makes it across the
epithelial cells of the GI to the capillary wall.
Usually, most of it is absorbed
in the small intestine
where there's a large surface area and
villi and microvilli can move it around.
So that's why we think about the rate
of time to make it to the bloodstream,
it's much longer in an oral medication because
it has lots of other steps to go through.
Now, impact of first pass effect;
remember, it's significant
because oral medications go through the GI
tract and are often inactivated by the liver.
Time of onset.
Well, it's really variable with oral medications,
but we know that it is the slowest route, okay?
So, if I'm in intense pain, do I
want a medication that's oral?
There are some more efficient
routes that we'll talk about.
So, oral routes are also
impacted by multiple variables:
the pH of the GI system, how
fast the stomach empties.
Was there food in the stomach
when they took the medication,
other drugs they're on, or coatings of the drug.
So, there's just a lot of
variables with oral medications
that can make the onset really variable.
Now… so, why would we give a medication this way?
Well, it's really cost effective.
It's usually the cheapest route to give
medications, and it's pretty convenient;
simple and straightforward, if
you're okay with swallowing a pill.
Now, as far as safety, there's not any extra
risk for infection, or fluid volume overload,
and there's plenty of time to try
and reverse the drug, if needed.
Other routes, you'll see that we have no time
for reversibility, but with oral medications,
because it takes longer for them
to make it to the bloodstream,
we've got some time to try
and reverse the medication
if the patient is having any adverse effects.
Okay, now, there are 2 times you do
not want to crush an oral medication.
Enteric coated is 1 of them.
The purpose of an enteric coating
is that it's pH sensitive.
Aha! Remember when we
talked about the difference
in the pH from your stomach
to your small intestine?
That's what makes the magic
of an enteric-coated tablet.
It's pH sensitive.
So it increases the likelihood
that the medication
will dissolve in the small intestine
instead of the stomach.
That's a really good idea if
the medication you're taking
is really irritating to your stomach,
like aspirin or potassium.
So, crushing these would result in this being…
the medication being absorbed in
the stomach instead of the intestine,
then we're risking really
irritating the stomach lining.
Now, why is that a bad idea?
Well, irritating your stomach lining is no fun,
but it also puts your patient at
risk for peptic ulcer disease,
and we definitely don't want to encourage that.
So, enteric-coated medications are
in a little coating or a little jacket,
so that they're more likely to
dissolve in the small intestine
versus the stomach for medications
that are really hard on the stomach.
Now, the other ones you don't want
to crush are sustained release
and this can be really dangerous.
The purpose of sustained release is that
small amounts of the medication
will be released over time.
If you crush that medication, you're going
to get a boom…a massive overdose.
This is particularly problematic
if you have a patient
who's on a sustained release pain medication,
you can cause that patient to
go into a respiratory arrest.
So, the 2 types of medications
that you don't want to crush
are sustained release medications
and enteric-coated medications.