So what is your goal in terms of
management of your patient with epilepsy?
Goal of drug therapy is so
that you become seizure-free
or at least, to
limit the seizures
because, remember, the Lennox Gastault,
say that your child is having
200 seizures per day, huh?
At this point, your first step –
your first priority is, my goodness,
minimize the number of seizures.
Did you become free of seizures?
Well, it’s all case
dependent, isn’t it?
And you want minimal
And that’s a big deal with
antiepileptic drugs as we shall see.
Monotherapy is always preferred
because the more number of
antiepileptic drugs that you’re on,
the cocktails will then bring about
more risk for adverse effects.
Most patients could be controlled
with one drug, thank goodness.
Treatment is generally indicated
after a second unprovoked seizure
because after that first one, it
could be a trigger of seizure,
a second that’s unprovoked, then
you start thinking about management.
Medications should not be
stopped abruptly ever -- ever--
unless absolutely necessary due to the
serious side effect that the
patient might be experiencing.
Let’s talk about the drugs.
We’ll begin with
So what does this behave like?
Well, you should remember that this
behaves like a sodium channel blocker,
It kind of behaves like lidocaine, okay?
But you can’t use lidocaine here.
By blocking the sodium channel,
hopefully , hopefully, hopefully,
you’ll be able to decrease
What are the types of seizures
that you’re looking for primarily?
Well, seizure type here for
phenytoin, definitely focal.
So either simple partial
or complex partial.
Generalized could be used
but your focus, please, should be
on partial or focal,
Let’s talk about
the side effects.
Many of these are
up and down the body
has huge issues.
You could have cardiovascular deficits.
The gingiva could undergo hyperplasia,
coarsening of the facial features.
You could have cerebellar atrophy.
You might have what’s
known as lymphadenopathy
and you could have something in a child
known as your fetal hydantoin syndrome.
Contraindicated in pregnancy.
But in pharmacology, if you remember,
you’ve done your phenytoin
in greater detail
and you talked about fetal
Your patient, your pregnant woman,
who has been taking phenytoin,
and then the child that’s been born,
low set ears, microcephaly,
everything that you would
expect with congenital issues.
This is phenytoin.
Also, please don’t
forget in pharm,
that phenytoin could
be part of the HIPP,
H-I-P-P, for drug-induced SLE.
Do you remember that?
What does HIPP mean?
Those are slow acetylators.
Do you remember when you
You’ve talked about
With phenytoin, it’s a little bit
different, but could also result in SLE.
Do not forget that.
That is a clinical pearl that you
want to take with you for sure.
Let’s move on to
Also, mechanism action,
keep it simple,
sodium channel blocker.
But the first line of treatment
is a little bit different here.
With carbamezapine, may worsen myoclonus
and absence seizures, keep that in mind.
But you could also use it for
focal and then also do not forget
that you could use this
for trigeminal neuralgia.
Carbamezapine, first line.
And carbamezapine, a couple
of things that are important,
you must know that it may
then bring about SIADH.
In other words, it might actually
increase the levels of ADH.
And in physiology,
if you remember,
you are then going to increase
your ECF volume, aren’t you?
And once you do that, what
happens to your sodium levels?
And please, don’t forget
As rare as it may be,
you must know it.
Let’s talk about Depakote
or valproic acid,
It could be a sodium
kind of like your
carbamezepine and phenytoin.
And could also a GABA receptor agonist.
Remember, what are we trying to do?
You’re trying to make your patient
seizure-free, if at all possible.
What are we looking for?
Well, you have all kinds
of seizures here.
You can have partial with
generalized or absence.
Side effects here would be
weight gain, tremor, hair loss.
In other words, alopecia,
Whereas with phenytoin, it
would be hirsutism.
Okay, so phenytoin and valproic
acid, a little bit different.
Take the P in valproic or Depakote
and alopecia, means hair loss.
another big one is called
In fact, the liver might die quite early.
And there is a gene here, in
which we’ll take a look at,
known as your
polymerase gamma, okay?
Polymerase gamma, POLG.
And that’s new information
that you want to keep in mind
because that hepatotoxicity is a
big one, ladies and gentlemen,
and it’s called hepatotoxicity,
don’t forget that.
Along with this, there’s something else
that I want to bring to your attention.
It’s also contraindicated
So now, we have two drugs
that I’ve mentioned to you
that are contraindicated in pregnancy that
you must know for your boards and wards.
With phenytoin, we call that
fetal hydantoin syndrome
and the child there would look
like microcephaly, low set ears,
which you would expect
with congenital issues.
With valproic acid, as sad it may
seem, let me give you a description.
You know what this means?
Okay, so I’m referring to Spock.
But what’s the show, a movie?
In Star Trek, there’s a character, his
name is Klingon-- or the species.
What do you know
about this Klingons?
If you know nothing about
this, don’t worry about it.
The point is they have the front
of the head, the frontal regions,
in which it looks
like it’s protruding.
In other words, there is premature
closing of the frontal bone.
Therefore, causing protrusion
of the frontal area.
It looks like a Klingon,
We call this trigonocephaly.
That’s new information that you
want to keep in mind, please,
as you know about valproic acid.
Now, let’s quickly walk
through some barbiturates.
what does that do?
GABA receptor agonist.
is this going to increase the
duration or the frequency?
Yes, it increases the duration of
your GABA receptor being open,
so that chloride can
come in, right?
Remember that from pharm.
Sedation, mild addiction potential,
always, always with barbiturates.
And my goodness gracious, once
we have addiction kicking in,
then what are you worried
about with pheno?
The barbiturates may then cause impediment
or inhibition of your respiratory center.
Not good, not good.
Keep things in mind, please.
As I said, monotherapy would be the
preferred method of management of epilepsy.
Take a look at the side effects, man.
Pretty severe, huh?
You pay attention to
your letter T here.
Ethosuximide, called Zarontin.
The reason for the T is because
where are we once again?
In the head.
That’s your problem.
So when you say T type,
why would you talk about the T-type
calcium channels in the heart?
You know what I’m saying?
So you’re going to use the T
type calcium channels where?
That’s where you’re going to
inhibit the calcium channel.
Use the T in ethosuximide
to then help you
understand or memorize
the mechanism of action.
It is the drug of
choice for absence.
What does that mean to you?
In childhood, generalized
seizure in which the patient
is staring off into space for seconds.
Side effect: GI
Sedation, ataxia, weight
gain at high doses.
This is lamotrigine.
These are some of your other drugs
that you want to keep in mind.
It could be a sodium channel
blocker or a glutamate antagonist.
Partial with generalized and risk here,
at least know Steven-Johnsons syndrome.
What does that mean to you?
Is that dangerous?
Increases the risk of mortality.
You’ve heard of
You’ve heard of toxic epidermal necrolysis.
Know that for lamotrigine, please.
We have another one
What are you trying to do?
Slow down the partial seizures.
Topamax or topiramate.
Really here, it may be
blocking your glutamate,
partial with generalized, weight gain,
and make sure you know
about renal stones.
That’s the clinical pearl here.
You have another one
T type calcium channel.
When did we last see this?
With ethosuximide, T type.
Partial, generalized, weight gain and
you could also see renal stones.
Topiramate and zonisamide.
And we have Felbatol.
Just a couple of things here.
I’m going through this quickly
because here, the amount of detail
that you want to know is minimal.
The amount of time that I spent with phenytoin,
carbamezapine, valproic acid and such,
that’s where you
want to spend time.
But just to make sure we’re complete, I’m
walking you through all antiepileptics.
Here, you want to know about liver
failure and aplastic anemia, please.
Those are important.
A couple words of our
last antiepileptic drug
that we’ll take a look
In terms of its mechanism of action,
there are many theories out there.
Anything that would slow down your seizures
would obviously be the answer choice.
Partial with generalized,
somnolence would be a side effect.
And self-limited, rare, but could
occur, known as akathisia.
In other words, movement disorder.