Welcome back. Today we are talking about pharmacology. I've been doing some videos
talking to you about specific drug categories and I realized I need to take
a step back and talk to you first about what is pharmacology and how do we get
the information we use at the bedside every day. So we're going to take care of
that and look at how drugs go from idea to being at the bedside right after this.
Welcome back, my name is Tammy and this is NurseMinder and on this channel we
do everything nursing so if you're new here consider subscribing below so that
you get the next video when it's released. Pharmacology is the study of drugs.
Now just as a quick aside, when we're looking at medical terminology there are
key elements that we can look at to help us explain what a word means and this is
the suffix, prefixes, endings. And so in pharma-cology, ology means "the study of", so
when you see that at the end of any word you know that you're looking at the
science that studies something. In this case Pharma means drugs so we are
looking at the study of drugs. Now at the bedside healthcare providers are mostly
focused with pharmacotherapeutics and this is therapy of drugs. So this is the
use of drugs to treat, prevent, and diagnose diseases. Now we're often
focused on the therapeutic effect - the thing that we want to happen- like when
you have a headache and you take an acetaminophen your headache goes away,
yay! But we also need to understand the
adverse effects; those things that can happen that we don't necessarily want. So
maybe I feel really lethargic after I take that acetaminophen or I have got a
bit of a stomach pain. So these types of things we also need to be aware of as a
healthcare provider. Now Pharmacotherapeutics takes into
consideration two other classifications of drug studies. So we have
pharmacodynamics, and this is the "do" think of the D in dynamics as what do
my drugs do. So are they in the body to replace or substitute for something
that's not in a sufficient volume, so maybe an
example here would be an antidepressant in that our bodies not making enough of
the happy hormones and so the antidepressants are coming in to replace
and substitute. Is it an enhancement or a stimulation of maybe something that
should be working that's kind of got a little lazy maybe. So for instance maybe
my red blood cells aren't being produced at the rate in which I need them so I'm
going to take something that stimulates production of red blood cells. Is the
role of the drug to stop or to slow down processes. So when I have anxiety I feel
all a little jittery I take a medication to calm those firing of the nerves
signals. So I want to slow it down. Or interfere with processes - so maybe I've
got an infection going on and I need an antibiotic to interfere with that
replication of bacteria that's causing me to feel really sick. So
pharmacodynamics is really looking at what does the drug do in the body - so
what is its role. This gives us information about our pharmacotherapeutics.
The other piece is pharmacokinetics. Kinetics is movement so
how is it traveling through the body to where it needs to go. This involves
absorption - so is it being absorbed through the stomach or through the skin;
how is it broken down in the body - does it need to go through the liver, does it
need to bind to a protein - how is it excreted; so am I going to get rid of it
through the urine or through my stool or through my respiratory system- and then
how is it distributed. And distribution is looking at things such as, uh things that
would impact distributions such as maybe the amount of fat tissue or the blood
vessel circulation; so if I've got really poor circulation to my feet and I want
my antibiotic to go down there interfere with that bacteria, well it may not
actually be able to get there because of the lack of circulation. So
distribution. These elements of pharmacokinetics give us information
that we use at the bedside in our pharmacotherapeutics on a daily basis.
It gives us information about onset of drugs, so once they've studied all these
pieces I know how long I should expect for that drug to kick in and start to
work; its peak duration; how long I can reasonably expect it to stay and that
includes its half-life - that's another concept involved in pharmacokinetics - and
then it gives us our loading doses, critical doses, things like that. So
pharmacotherapeutics involves pharmacodynamics, the doing of the drug
what is its role, and pharmacokinetics the movement of the drug throughout the
body so that when I'm at the bedside I can treat and care for my patient
appropriately. Next I want to talk to you about the process drugs go through from
generic idea into that pill bottle on your shelf. Before we talk about how we go
from an idea to an actual drug that's used in patient population today, I think
it's important to know where our drugs are coming from.
So there's many sources of drugs from where we can derive inspiration. So
plants for example is one place where find. and poppy seed for opium.
Foxglove was actually used in digitalis, a lot of these things are now made
synthetically a bit just a little bit of a history there. We still use plant based
medications. Animal source. Initially when insulin was first brought out it
came from a cow and a pig's pancreas. Thyroid and growth hormone also initially
came from animal by-products or animal sources such as the hypothalamus my
apologies. There are inorganic drugs such as aluminum, iron, gold many of these are
used to treat a variety of symptoms. And now of course many of
our drugs are made synthetically where the scientists are genetically
engineering elements to create a product that will treat or cure or diagnose an
illness. So once a chemical is believed to have therapeutic value, it needs to
undergo this rigorous testing process and assessment process outlined by the FDA, the Food
and Drug Administration. And the first step is preclinical trials. Now you can
run all the data and simulation scenarios you want in a computer with
numbers, but until you put it into a biological environment similar to humans
we won't know what it actually does so animal testing is extremely important as
the first step to identify whether it's safe to try in humans, and so these are
going to be strict studies and they're looking for 1) does the drug have the
therapeutic effect intended? and 2) does it cause any adverse events that would
be too extreme, to toxic, cause harm to fetus and if that's the case they
stopped the drug trial right here. But if it's deemed to be safe to go on, if it's
safe, we're gonna then go into Phase One. If it's not safe then it is stopped and
abandoned at this very first step. In phase one these are clinical trials in
which the drug is allowed to be tested in patient populations that are healthy.
We want to just make sure that it's safe to put into any body first of all, so
we've got healthy, usually young men and women;
now women of childbearing age may not be included depending on what the drugs
intended effect is. So first is healthy patients looking to see if the drug has
the intended effect, what are the adverse events, does it cause anything that would
cause the study to be shut down? If there are harmful effects it's stopped
here as well. At this stage the drugs are given free of charge; they are not, um,
there's not a burden to this person to participate in the study financially and
they are followed and documented to see just what is happening with this drug in
a healthy human being. Sometimes drugs that showed promise in animals don't
show anything in humans and that's another reason why this drug would be
stopped here at this stage is that it doesn't have the therapeutic intent
needed. If there is promise,
then we're gonna want to Phase Two. Now phase two again is another tightly
structured study. These involve expert clinicians who are following these
patients but now we're looking at people who actually have the disease in which
it was intended for. So we have a really small group of people - they are again
informed about consent and informed about side effects and potential
benefits, they volunteer to be a part of this study and we're looking to see
if it still has the intended therapeutic effect with minimal impact and adverse
events. If it does not and this is sometimes where studies fail as well. Now
in Phase three we're opening this up to a wider market of people with the
disease process intended to be treated. The physicians are educated on the
intended therapeutic effect the adverse effects and they monitor their patients
closely and report back all of the findings to the clinical trial lead. This
information is then shared with the FDA. If it is deemed to be therapeutic with the
intended effect with minimal adverse effects, harmful effects to the patients,
it has to go through FDA approval and now this is where our generic; this has
been a generic name the whole time - I should write that here - it's only had a
generic name the whole time. Once it receives approval, then the person of the
companies making that drug can now give it a brand name and it is for consumer
use and the FDA continues to follow. This never leaves FDA's area of
responsibility because sometimes once it's opened up to the wider population,
we start to see adverse events that we didn't see in any of these other stages
and drugs have been pulled even after they've gone through this whole trial
process; they can still be pulled even in this timeframe.
So these drugs in phase four are under continued evaluation. Okay so we
started out with an idea. Preclinical is with our animals. We need to make sure
it's safe in a biological environment similar to ours.
Generic name only which represents the compounds in the drug. Phase one we're
gonna go to healthy individuals, young men and women, we want to see what the
actual effect is and side effects. If that passes, we go to Phase two which is
people with the disease, very small group, tightly coordinated, really structured
clinical investigators are following this entire process. If that's positive
we go to the next stage which is phase three which goes into a wider market
under the physicians control and they are still reporting back to FDA. If
there's nothing untoward that is visible at this point, it goes for approval and
gets a brand name and is then on the market. So if you have a patient that
comes in - there's a lot of drugs out there - and our process could take years
before it's actually approved for public usage in our countr. So maybe you've got
someone who's talking about, I've heard about this new drug that has got promise
in curing cancer. Well we need to understand we're in this process it is
so we can educate our patients about what's happening with those drugs. Thanks
for watching. today we talked about what is pharmacology and pharmaco-
therapeutics and how does that impact our work at the bedside.
Additionally we looked at where drugs, the process they take to go from idea to
actually being used in our patient population. That information is all
really important as we are working directly with our patients and we need
to be educating them and be aware of those processes so that we can give them
the best information to make the most empowering decisions for their journey.
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it a great day :)