Week 12: Anticonvulsants

Question 1

focal onset seizure affects the brain by?

example

Answer 1

one portion/hemisphere
pt is aware but impaired awareness

ie: jerking movements or strange sensations

Question 2

generalized onset seizure

Answer 2

affects both side of brain and LOC
impaired awareness

tonic clonic, absence

Question 3

unknown onset seizure

Answer 3

tonic clonic, absence

Question 4

phenytoin (Dilantin) indications and MOA

Answer 4

tonic clonic & partial complex seizures

MOA: inhibit and stabilize electrical discharges in the motor cortex of the brain by affecting Na ions during nerve impulses

highly protein bound

Question 5

phenytoin c/c

Answer 5

NO alcohol, bradycardia, 2/3rd degree AV block, syncope
NO preg/lact
caution elderly
ok peds

• caution in hypotension and myocardial insuff,
• renal/hepatic impairment
• sudden withdrawal = rebound status epilepticus
• narrow TI (10-20)

Question 6

phenytoin ADE

Answer 6

Agitation, dizziness, drowsiness, headache, nystagmus, hypotension, tachycardia, nausea, vomiting, anorexia, altered taste, hypersensitivity reactions (rare), suicidal ideations (rare), blood dyscrasias (rare)

TOXICITY (>20) if ataxia, confusion, dec mental status, lethargy!!!

gingival hyperplasia, discolored urine

Question 7

after 3-8 weeks of starting dilantin, if get fever, skin rash, lymphopathy…

Answer 7

hypersensitivity syndrome to dilantin (CALL NEURO!)

Question 8

carbamazepine (Tegretol) indc & MOA

Answer 8

focal and generalized onset of seizures

MOA: affect NA channels, slowing influx of Na in cortical neurons and slowing spread of abnormal activity

Question 9

carbamazepine (Tegretol) c/c

Answer 9

BBW: Steven johnson syndrome & toxic epidermal necrolysis in CHINESE PTs
(strong HLA-B1202 allele)
screen prior!

BBW: blood dyscrasias (lower WBC, bone marrow = pancytopenia and aplastic anemia)
[get baseline CBC, CMP, TSH before starting]

BBW: dermatologic toxicity

NO preg/lac

Question 10

carbamazepine (Tegretol) ADE

Answer 10

Agranulocytosis, drowsiness, dizziness, ataxia,
n/v, skin rash, pruritus, constipation, tremor, behavior changes (rare), suicidal ideations (rare), multi-organ hypersensitivity reactions (rare), hepatotoxicity (rare)

Question 11

carbamazepine (Tegretol) toxic sx’s

Answer 11

HTN, tachycardia, stupor, agitaiton, respiratory depression, nystagmus, urinary retention, seizures, coma

Question 12

Lamotrigine (Lamictal) indication & MOA

Answer 12

partial seizures, gen tonic clonic

block voltage Na channels
inhibit presynaptic release of glutamate and aspartate in neuron

Question 13

Lamotrigine (Lamictal) c/c

Answer 13

BBW: serious skin reactions

rebound status epilepticus w/ sudden w/drawal
Ok > 2 years old but increased risk of skin reactions

Question 14

Lamotrigine (Lamictal) ADE

Answer 14

report any new onset of rash

• Dizziness, headache, GI upset, diplopia, ataxia, insomnia, skin rash
  rare: SI, blood dyscrasia, multi-organ hypersensitivity reactions

Question 15

Lamotrigine (Lamictal) drug to drug interactions

Answer 15

combined oral contraceptives (decrease lvls of lamictal)

Question 16

zonisamide indic & MOA

Answer 16

partial seizures

blocks voltage dependent Na and Cl channels

Question 17

zonisamide ADE

Answer 17

Somnolence, anorexia, dizziness, headache, agitation, memory difficulties, aplastic anemia (rare), agranulocytosis (rare)

decrease sweating = hyperthermia = worse in peds pts

Question 18

zonisamide c/c

Answer 18

NO SULFA!!!!!
rebound seizures
NO preg/lac
ok > 16 yrs old

Question 19

Succinimides: ethosuximide, methsuximide

indication & MOA

Answer 19

indc: absence seizure

MOA: decrease nerve impulses and transmission in motor cortex

Question 20

Succinimides: ethosuximide, methsuximide ADE

Answer 20

GI distress
sedation
ataxia, lethargy, headache, rash, pruritus, mood changes
Lupus sx’s 
Narrow TI 

Toxicity: CNS depression, resp depression, acute n/v

Don’t take with alcohol!
Decrease birth control - use backup method

Question 21

Succinimides: ethosuximide, methsuximide c/c

Answer 21

monitor during preg
rebound seizures
> 3 yrs old ok

Question 22

valproic acid indic & MOA

Answer 22

focal/partial seizures, generalized seizures, focal onset impaired awareness, absence

increases and enhances GABA, mimics action at postsynaptic sites
blocks voltage dep NA channels = suppression of high freq, repetitive neuronal firing

Question 23

valproic acid ADE

Answer 23

Headache, drowsiness, dizziness, nausea, vomiting, tremor, visual disturbance, weight gain, behavioral changes, hypersensitivity reactions (rare), SI (rare), brain atrophy (rare)

Narrow TI
Toxicity: CNS depression, confusion, jaundice

Question 24

valproic acid c/c

Answer 24

BBW: hepatotoxicity
BBW: severe pancreatitis

NOOOO Preg!
rebound seizures
NO elderly (beers)

Question 25

gabapentin ind & MOA

Answer 25

focal seizures

GABA analogue that bind to brain receptors
doesn’t bind/mimc GABA

Question 26

gabapentin ADE

Answer 26

Dizziness, drowsiness, fatigue, ataxia, peripheral edema, abnormal thinking
Neuropsychiatric events in 3-12 year olds
Suicidal ideation

Question 27

gabapentin c/c

Answer 27

Only if benefits outweigh risks in pregnancy and lactation
Caution in renal, elderly
Somulence 
Caution substance abuse hx
Rebound seizures

Question 28

topiramate (Topamax) ind & MOA

Answer 28

Focal seizures, primary generalized tonic-clonic seizures
Migraines and cluster h/a

block NA channels or potentiate GABA

Question 29

topiramate (Topamax) ADE

Answer 29

Ataxia, paresthesia, dizziness, somnolence, difficulty concentrating, mood changes, weight loss
SI (rare)
Decrease sweating and hyperthermia
Oligohidrosis / hyperthermia

Question 30

topiramate (Topamax) c/c

Answer 30

NO preg
no < 3 months
caution renal, hep, elderly
rebound seizures

Question 31

levetiracetam (Keppra) ind & MOA

Answer 31

focal onset seizures, generalized onset seizures

inhibit burst firing w/o affecting normal neuronal excitability

Question 32

levetiracetam (Keppra) ADE

Answer 32

Somnolence!! dizziness, somnolence, nervousness, mood disturbances, SI (rare)

Rare dermatologic reactions and blood dyscrasias

Question 33

levetiracetam (Keppra) c/c

Answer 33

fewer drug2drug intxn bc NOT met by P450 sys

rebound seizures
children inc risk of psychiatric sx’s