Hi, welcome to our pharmacology video series.
I'm gonna talk about drug therapy during pregnancy.
Now, drug therapy during pregnancy is an important discussion
because two-thirds of pregnant patients take at least one medication
and most take more while they're pregnant.
Now, what kind of things do they take?
Well, for sure, they've got issues with nausea, and constipation,
and even a little more serious, obviously, preeclampsia.
So we're thinking about the types of medications that pregnant women take.
Over the counter stuff would include things for nausea or constipation.
It can also take issues with preeclampsia.
For chronic disorders such as hypertension, diabetes, and epilepsy,
they might need to be on some prescription medications.
They also might have infectious diseases or sadly even cancer.
Now, last category would be drugs that are abused such as alcohol, cocaine, or heroin.
So you kinda got the picture but two-thirds of pregnant patients take at least one medication,
most pregnant women take more than one during their pregnancy.
So that's why we need to have a pretty open conversation with each other today
so you're educated when you're working with patients who are pregnant.
Okay, so what are some of the adverse drug reactions?
Well, these drugs can adversely affect both the pregnant patient and the fetus.
That's why it's important that you understand the impact of these drugs.
Let me give you just a few examples, some of the unique ones.
So if the patient has heparin -- takes heparin, it can cause osteoporosis.
If they take prostaglandins, that could stimulate uterine contractions.
And there are certain pain relievers that are used during delivery
that could also depress the respiration in the neonate.
So there's just 3 examples of somewhat adverse drug reactions
if a pregnant patient takes these meds
but we're gonna get way more information on that.
Before we do though, I wanna talk about fetal development.
Now, if we divide it into just roughly 3 phases about fetal development,
let's say from conception through week 2, that's the first phase.
The second phase is weeks 3 through 8.
We'll call that the embryonic phase.
And the third phase is the fetal period.
That's week 9 all the way through delivery.
Now the reason we've put this up here
is because we want you to kinda see what's going on is this fetus -- is developing.
But look at weeks 3 through 8.
Medications here can impact some gross malformations can be produced by teratogens.
These are medications or substances
that can cause these abnormal changes in the developing fetus.
Now, look at what you have on the list there. CNS, heart, eyes, upper and lower limbs, and ears.
I just want you to kinda take a look roughly at the time.
Don't memorize these. Just get a feel for what happens in weeks 3 through 8.
Now, for weeks 9 through delivery,
this is where we have the functions are disrupted within the teratogen exposure.
So have problems with the palate, with the teeth, or the external genitalia.
So pause the video, kinda familiarize yourself first of all
with the names of the first 3 categories,
make sure that's solid in your mind, then take a look at the red boxes
that talk about gross malformations or functional dysfunction.
So look at those two red boxes, make sure that's solid,
and then briefly review what is formed and what goes on during those periods.
Then just restart the video and join us again.
Okay, now that you've invested that time in looking in that drawing
and I love how those graphics help make words come alive.
So the time you invest in really looking at those drawings will pay off for you. I promise.
But now we're gonna talk about 4 factors that affect placental drug transfer.
You know how it happens because you've looked at the drawing.
Now, let's talk about 4 things you're gonna want to be aware of.
The fetus in stage 2 of development is the first one.
Remember, earlier in this series, we talked about the 3 phases in the stages of development.
Go back and take a quick review of that or just jot yourself a note now
that when you're reviewing your notes later,
to take a peak at that beginning part of this video series.
Now, the second category is the strength and the dosage of the drug.
That's also gonna impact the effect on the fetus.
So the stronger the drug, the larger the dose,
the more significant impact we can expect on the fetus.
Now, 2 more categories.
The genetic makeup of the mother is gonna impact the amount of drug
that's active and available.
So there's a lot of factors that we're kinda lumping in there together
but I just want you to be aware of hey, everybody's body is different
when it comes to pharmacokinetics and pharmacodynamics
so the genetic makeup is what impacts that.
So know that how the mom's body functions, how it interacts with the drug,
is gonna have a role in how big the significance of the impact is on the fetus.
Now, one category left. Of course, what else would we call it besides other factors?
Let me give you an example but we're talking about other variables that impact the mom.
For example, nausea and vomiting goes along with certain phases and stages of pregnancy.
Some poor women have to deal with it the entire pregnancy
but if the mother's vomiting and it's an oral medication,
she may not absorb as much of the drug.
So therefore, if mom doesn't absorb as much of the drug,
the fetus is not as exposed to much of the drug.
So mom doesn't have as much of drug absorbed, the fetus is exposed to less of the drug.
So we're thinking about the 4 factors. There you go.
Stage of development, strength and dose of the drug, mom's genetic makeup,
and then these other variables that are different based on the mom.