Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/62

Click to flip

62 Cards in this Set

  • Front
  • Back
Def: Seizure
transiet episode of brain dysfunction resulting from rhythmic, synchronous nueronal firing
Def. Epilepsy
group of chronic disorders characterized by recurrent seizures. It's the 2nd most common nuerological disorder.
Mech of Action of antiseizure drugs
decrease excitation, enhance inhibition, modify neuronal excitability of ion channel that mediate neuronal firing/rhythmicity
Mech of Action: Decrease in Excitation
excitation decreased by decreasing Glutamate.

(phenobarbital): modulate GABAa-R, decreasees glutamatergic transmission, commonly used in infants*//

Topiramate: Inhibit AMPA/KA receptors >> no glutamate binding.//

Felbamate: binds NMDA-R to block glutamate binding.//

Lamotrigine: inhibits release of Glu from presynaptic membrane.//
Mech of Action: Enhance Inhibition via GABA transmission
ex: Topiramate, Felbamate://

Valproate: induces GAD, converting more Glu to GABA. Also, inhibits GABA-T decreasing GABA breakdown.//

Tiagabine: block GAT-1, decreaing reuptake of GABA from the synapse into the neuron and glial cell.//

Pheobarbital/Levetiracetam: positive effect on GABAa-R. //
Mech of aCtion: Alter ion channel activity
Decrease Sodium influx: oxcarbazepine, phenytoin, valproate, topiramate, zonisamide.//

Enhance K efflux: Oxcarbazepine, topiramate. They prolong AP so few APs per unit time.//

Decrease Ca influx: Ethosuximide, valproate, zonisamide, Gabapentin, levetiracetam, oxcarbazepine.
Types of Seizures
There are Partial seizures (localized onset) and generalized seizures that have no localized onset. Partial subtypes include simple partial, complex partial, partial seizure secondarily generalized.

Generalized subtypes include Tonic-clonic (grand mal) and abse'nce (petit mal).
Partial Seizures: Simple Partial
Conciousness is PRESERVED. Sensory 'auras' or limited unilateral motor convulsions. 20-60 sec duration
Partial Seizures: Complex Partial
IMPAIRED CONCIOUSNESS: automatisms common, post-ictal confusion and or lethargy. Most common refractory seizure in adults. 30 sec to 2 min duration.
Partial Seizures: Partial seizure secondarily generalized
it's a partial seizure that progresses to generalized tonic-clonic seizure. 1-2 min duration.
Generalized seizure: Tonic-Clonic (grand mal)
loss of conciousness, major convulsions, tonic spasm of the body followed by clonic jerking, prolonged ictal stupor. 1-2 min duration.
Generalized seizures: Abse'nce (petit mal)
abrupt interruption of conciousness associated with starring and cessation of ongoing activities. Symmetrical automatism and or mild jerking common. LACK OF POST ICTAL ABNORMALITIES.
How would you differentiate between complex partial seizures and Absence (petit mal)?
Absence lack post-ictal abnormalities.
What does post-ictal mean?
It means after the seizure. So individual with complex partial seizure would be confused afterwards but Absence, once the seizure is gone, the person does not show confusion.
Frontline drugs for Partial Seizures?
Carbamazepine, phenytoin, oxcarbazepine, lamotrigine, valproate
frontline drugs for Tonic-clonic seizures?
valporate, phenytoin, carbamazepine
frontline drugs for absence (petit mal)?
ethosuximide, valproate
Phenytoin
inhibits Na channel, part of frontline drugs for all seizures.//

NONLINEAR relationship between dose and [plasma], so small increase in dose >> large [plasma] increase.//

adverse: gingival hyperplasia, hisutism, coarsed facial features, may interfere with thyroid function test.
Carbamazepine
related to tricyclic depressants, Na ch blocker.//

induces own hepatic metabolism. //

adverse: LIVER DAMAGE, liver function test REQUIRED BY FDA.
Oxcarbazepine
safer than carbamazepine, **blocks Na and Ca channels, enhance K eflux**//

Less hepatic induction than carbamazepine.//

Adverse: hypnatremia, STEVEN JOHNSON SYNDROME, decreases T4.//
Phenobarbital
a barbiturate, modulates GABAa-R and decreases glutamatergic transmission.//

COMMONLY USED IN INFANTS, NOT IN OTHER POPULATIONS.//
Gabapentin
amino acid ANALOG of GABA. decreases Ca influx by binding alpha-2-delta subunit of VG Ca channel.//

EXCRETED UNCHANGED, NO Rx INTERRACTIONS.

adverse effects: periph edema, behav. and thoughts changes in 3-12 yo. adverse effects similar to high dose diazepam.//
Tiagabine
GAT-1 inhibitor//

highly bound to plasma protein.//

adverse: Seizures, non-convulsive status epilepticus in non-epileptic patients***
Levetiracetam
inhibits delayed rectifier K channel, inhibits Ca channel, inhibit neg modulation of GABAa-R by Zn and beta-carboline.//

adverse: irritability, hallucination, psychosis. //
Felbatamate
inhibit NMDA, enhance GABA transmission.//

ONLY IN MEDICALLY REFRACTORY PTS.//

adverse: HEPATIC FAILURE. liver function test REQUIRED BY FDA.
frontline drugs for Tonic-clonic seizures?
valporate, phenytoin, carbamazepine
Note to self
previous drugs are for partial and general Tonic-clonic only. The next card is for Absence seizures ONLY.
Ethosuximide: In absence only!!!
inhibit T type Ca channel. //

adverse: bloody dyscrasias, skin rxn, photophobia, parkinson's like sx.
frontline drugs for absence (petit mal)?
ethosuximide, valproate
Valproic acid/sodium valproate
Inhibits Na ch, Ca ch and GABA-transaminase; stim GABA synth enzyme GAD, hyperpolarizes membrane.//

IDIOSYNCRATIC HEPATOTOXICITY. liver fxn test required by FDA
Phenytoin
inhibits Na channel, part of frontline drugs for all seizures.//

NONLINEAR relationship between dose and [plasma], so small increase in dose >> large [plasma] increase.//

adverse: gingival hyperplasia, hisutism, coarsed facial features, may interfere with thyroid function test.
Carbamazepine
related to tricyclic depressants, Na ch blocker.//

induces own hepatic metabolism. //

adverse: LIVER DAMAGE, liver function test REQUIRED BY FDA.
Lamotrigine
ADULTS ONLY. inhibits Na ch, Glu release. ONLY INDICATED FOR LENNOX-GASTAUT SYNDROME IN PT < 16 YRS OF AGE.//

Adv: Steven-Johnson Syndrome esp. if switched from Valproate.**
Oxcarbazepine
safer than carbamazepine, **blocks Na and Ca channels, enhance K eflux**//

Less hepatic induction than carbamazepine.//

Adverse: hypnatremia, STEVEN JOHNSON SYNDROME, decreases T4.//
Why does the risk of Steven-Johnson syndrome go up with Lamotrigine if the pt was previously on valproate?
Sodium Valproate (Valproic acid) inhibits p450, so this could lead to increase [lamotrigine] in plasma >>> toxicity.
Phenobarbital
a barbiturate, modulates GABAa-R and decreases glutamatergic transmission.//

COMMONLY USED IN INFANTS, NOT IN OTHER POPULATIONS.//
Gabapentin
amino acid ANALOG of GABA. decreases Ca influx by binding alpha-2-delta subunit of VG Ca channel.//

EXCRETED UNCHANGED, NO Rx INTERRACTIONS.

adverse effects: periph edema, behav. and thoughts changes in 3-12 yo. adverse effects similar to high dose diazepam.//
Tiagabine
GAT-1 inhibitor//

highly bound to plasma protein.//

adverse: Seizures, non-convulsive status epilepticus in non-epileptic patients***
Levetiracetam
inhibits delayed rectifier K channel, inhibits Ca channel, inhibit neg modulation of GABAa-R by Zn and beta-carboline.//

adverse: irritability, hallucination, psychosis. //
Felbatamate
inhibit NMDA, enhance GABA transmission.//

ONLY IN MEDICALLY REFRACTORY PTS.//

adverse: HEPATIC FAILURE. liver function test REQUIRED BY FDA.
Note to self
previous drugs are for partial and general Tonic-clonic only. The next card is for Absence seizures ONLY.
Ethosuximide: In absence only!!!
inhibit T type Ca channel. //

adverse: bloody dyscrasias, skin rxn, photophobia, parkinson's like sx.
Valproic acid/sodium valproate
Inhibits Na ch, Ca ch and GABA-transaminase; stim GABA synth enzyme GAD, hyperpolarizes membrane.//

IDIOSYNCRATIC HEPATOTOXICITY. liver fxn test required by FDA
Lamotrigine
ADULTS ONLY. inhibits Na ch, Glu release. ONLY INDICATED FOR LENNOX-GASTAUT SYNDROME IN PT < 16 YRS OF AGE.//

Adv: Steven-Johnson Syndrome esp. if switched from Valproate.**
Why does the risk of Steven-Johnson syndrome go up with Lamotrigine if the pt was previously on valproate?
Sodium Valproate (Valproic acid) inhibits p450, so this could lead to increase [lamotrigine] in plasma >>> toxicity.
Topiramate
inhibits Na ch, enhance GABA transmission, activate K ch, AMPA/ KA-R antagonist, carbonic anhydrase inhibitor.//

adv: metabolic acidosis, renal calculi, weight loss
Zonisamide
inhibits Na, and Ca channels; weak carbonic anhydrase inhibitor. //

adv effect: sulfonamide derivite drug so possible allergic rxn,
Vigabatrin
IRREVERSIBLE inhibitor of GABA degradation enzyme, GABA-T (Transaminase).

Adverse: Long use may cause permanent visual field deficits, psychosis in pts with preexisting mental disorders.
Drug Interractions: Which Rx has interraction with almost all of the antiseizure drugs?
oral contraceptives
Which antiseizure drugs have the most interractions?
Carbamazapine, Phenobarbital, Phenytoin. These induce hepatic enzymes.
Which antiseizure drugs inhibits hepatic enzymes?
Valproic Acid
Which antiseizure drugs have no known Rx interractions?
Gabapentin (aa analog of GABA), Levetiracetam
What aniseizure drug should NEVER be used off-label?
Tiagabine because it could cause seizures in non-epileptic patients.
Status Epilepticus Def.
continuous prolong seizure >5-10 min, or multiple seizures in rapid succession.//

Most common is generalized tonic-clonic status epilepticus, which is life threatening emergency.//

Use IV meds in these patients.
What drugs to use in Status Epilepticus?
IV Lorazepam, IV or rectal Diazepam. Also, iv Fosphenytoin//

In Absence SE, NO barbiturates, substitute valproate for fosphenytoin.
What's Fosphenytoin?
This is a more water soluble form of phenytoin useful for IV or IM injections.
Def. Infantile Spasm
epleptic syndrom characterized by myoclonic spasms. First attack before 1 yo in 90% pts.//

Refractory to usual antiseizure drugs.//

Use corticotropin, prednisone.//
Febrile Seizures, def.?
NOT a form of epilepsy. brought on by fever in infants and children.//

No Meds. Prophylactic rectal diazepam if prone to febrile seizures.//
Best way to manage Epilepsy with treatment?
Early dx, treatment with single drug for at least 2 years.
Antiseizure Rx and Pregnancy
many antiseizure drugs would reduce the effectiveness of oral contraceptives >>> unintended pregancy.
Drugs with teratogenic effects?
Valproate**, phenytoin, carbamazepine, phenobarbital
So what to do with pregnant pts?
consider either discontinuation prior and during the pregnancy if withdrawal does not posses serious threat to the pt. OR monotherapy with lowest effective dose.//