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Flashcards in Pharm anticonvulsants Deck (69):
1

definition of epilepsy

at least 2 unprovoked seizures separated by 24 hours

2

what single events can precipitate seizusres

withdrawal of CNS depressants
acute neuro illness or toxic systemic
fever

3

what is a simple partial seizure

minimal spread of abnormal discharge, normal consciousness, preserved awareness

4

what is a complex partial seizure

localized onset but discharge becomes widespread, almost always involves limbic system

5

characterstics of complex partial seizure

lip smacking, swallowing fubmling, scratching, memory loss or aberrant behavior

6

secondarily generalized seizure

partial that immediately precedes a generalized tonic clonic seizure

7

what is a generalized seixure

without evidence of localized onset, both brain hemispheres involved

8

what is a grand mal seizure

generalized tonic clonic
sudden, sharp tonic contraction followed by rigidity and clonic movements
patient may cry, moan, lose sphincter control, bite tongue or develop cyanosis

9

after grand mal seizure, patient may have

altered consciousness, drowsiness or confusion

10

postictal Sx of seizure

grand mal
generalized tonic clonic

11

what is an absence seizure

sudden onset and abrupt cessation, altered consciousness,
a blank stare
usually young children through adolescence

12

myoclonic jerking

brief shock like muscle contractions
occur in wide variety of seizures

13

atonic seizures

sudden loss of postural tone, head drop, fall to floor, slumping
many patients wear helmets to prevent head injury

14

AED treatments

suppress seizures but do not cure of prevent epilepsy

15

how do you switch AED Tx monotherapy

taper off initial AED after second AED is titrated to therapeutic level

16

MOA AED

affect ion channel kinetics
augmenting inhibitory neurotransmission
modulating excitatory neurotransmission

17

which AEDs are highly protein bound

phenytoin
tigabine
valproic acid

18

how are AEDs cleared

hepatic metabolism

19

Adverse effects AEDs

sedation, dizziness, blurred or double vision, difficulty concentrating and ataxia

20

MOA phenytoin

blocks sustained high frequency firing action potentials due to preferential binding to and prolongation of inactivated state of Na channel
also dec glutamate and enhances GABA release

21

PK phenytoin

not IM
erratic absorption
highly protein bound
low dose first order kinetics
high dose disproprotionate elimination

22

use of phenytoin

partial seizures, generalized tonic-clonic seizures

23

adverse effects phenytoin

diplopia, ataxia, nystagmus, sedation, gingival hyperplasia, hirsutism

24

long term adverse effects phenytoin

worsening facial features, mild peripheral neuropathy
abnormalities in vit D metabolism causing osteomalacia

25

cardiac effects of phenytoin

hypotension, bradycardia, cardaic arrhythmia, CV collapse, venous irritation and pain, thrombophlebitis

26

DDI phenytoin

related to protein binding
sulfonamides by dispalce phenytoin from site increasing the amount of free drug!
CYP2C9, increased warfarin!!!
CYP3A4, increased risk pregnancy on oral contraceptives

27

MOA carbamazepine

acts on Na Ch resulting in inhibition of high frequency repetitive firing
also acts presynaptically to decrease synaptic release of glutamate

28

PK carbamezepine

autounduction, increased expression of CYPs and UGT

29

use of carbamezapine

partial seizures, generalized tonic-clonic seizures, trigeminal neuralgia, mania in bipolar disorder

30

adverse effects carbamazepine

diplopia, ataxia, mild GI upset, unsteadiness, drowsiness
hyponatremia and water intoxication
idiosyncratic blood dyscrasias
rash, sometimes stevens johnson

31

what patients at higher risk stevens johnson syndrome reaction from carbamazepine

asians with HLA B*1502

32

DDI carbamazepine

hepatic enzyme induction leading to increased metabolism of other drugs

33

what drug inhibits carbamazepine clearance (increased levels)

valproic acid

34

what drug has fewer DDI than carbamazepine

oxcarbazepine

35

MOA phenobarbital

binds GABA and enhances GABA mediated current by prolonging Cl Ch

36

MOA gabapentin

analogs of GABA
bind 2alphadelta on vNtype Ca Ch decreasing Ca, decreasing release of glutamate

37

use of gabapentin

partial seizures, generalized tonic-clonic seizures, neuropathic pain
post herpetic neuralgia

38

adverse to gabapentin

somnolence, dizziness, ataxia, HA, tremor

39

MOA lamotrigine

like pheytoin suprres neurons through inactivation Na Ch
inhibits vCa Ch

40

uses of lamotrigine

> 2y.o with partial seizures or generalized
also used for monotherpay partial seizures
adjunct in primary generalized tonic clonic
absence
bipolar

41

adverse effects lamotrigine

dizziness, HA, diplopia, ataxia, nausea, somnolence, skin rash

42

DDI lamotrigine

concentrations decrease with use oral contraceptives (E component)
may lead to contraceptive failure in P only pill

43

MOA levetiracetam

binds to synaptic vesicular protein SV2A modifies synaptic release of glutamate and GABA through action on vesicular function

44

use of levetiracetam

adjunct for partial seizures in adults and children
primary generalized tonic clonix
myoclonic seizures of jevenile epilipsy

45

adverse effects levetiracetam

somnolence, asthenia, ataxia dizziness

46

adverse effect tigabine

cause seizures in some patients who take tiagabine for bipolar disorder, anxiety and neuropathic pain

47

MOA ethosuximide

reduce threshold Ca T type which are pacemaker for thalamic neurons

48

use of ethosuximide

absence seizures

49

adverse effects ethosuximide

gastric distress, pain , nausea and vomiting

50

DDI ethosuximide

valproic acid can inhibit metabolism of ethosuximide

51

MOA valproic acid and Na valporate

blocks firing of neurons through Na currents
blocks NMDA R mediated excitation
increased levels GABA in brain

52

use of valproic acid

absence seizures
myoclonic seizures
generalized tonic clonic seizures
partial seizures
status epilepticus (IV
bipolar disorder
migraine prophylaxis

53

adverse effects valproic acid

nausea, vomiting, abdominal pain, heartburn
fine tremor
weight gain, hair loss
hepatotoxicity and thrombocytopenia

54

what must you monitor if put patient on valproic acid

liver function because of hepatotoxicity

55

MOA diazepam

bind GABAa R
increase GABA Cl Ch to increase inhibitory membrane potentials

56

PK diazepam

lipophilic, goes to CNS in sec when IV
redistributes to fat quickly

57

why do you give a longer acting AED after giving diazepam

prevent seizure recurrence

58

therapeutic use diazepam

status epilepticus, adjunct, myoclonic, partial, and generalized tonic clonic seizures

59

adverse effects to diazepam

sedative
drowsiness
ataxia
behavior disorders

60

first DOC for partial seizures and secondarily generalized

carbamazepine
or lamotrigrine
or oxcarbazepine
or levetiracetam

61

second line of drugs for partial seizures or secondarily generalized

topiramate, gabapentin, pheytoin

62

first DOC for primary generalized tonic clonic or grand mal

valporate
lamotrigine
levetiracetam

63

second line for grand mal seizure

carbamazepine, phenytoin

64

first DOC for absence seizures

ethosuximide
or valproate

65

second DOC for absence seizures

lamotrigine
levetiracetam

66

first DOC for atypical absence of myoclonic or atonic seizures

valproate
lamotrigine
levetiracetam

67

teratogenicity of AED

increased risk congenital malformations

68

phenytoin teratogenicity

fetal hydantoin syndrome (abnormal skull, facial features, growth deficiency, underdeveloped nails or mild developmental delays)

69

what AED indicated in spina bifida

valproate