epilepsy Flashcards
1st gen anticonvulsants
• Phenytoin/fosphenytoin
• Valproic Acid
• Carbamazepine
• Ethosuximide
barbituates
benzos
3 AEs that would req discontinuation of 1st gen anticonvulsants
rash, blood disorders, hepatotoxicity
class: Phenobarbital, pentobarbital, mysoline
barbituates
most concerning SE of phenobarbital
decrease in cognitive function (IQ, attention, memory dysfunction)
AEs (dose related): ataxia, memory impairment, sedation, slowed thinking, abuse potential,
dependence/withdrawal, residual hangover effects
benzos
Phenytoin/Fosphenytoin enzyme metabolism
3A4 inducer (increased plasma concentration w/ estrogen, warfarin)
AEs:
o Nystagmus, dizziness, diplopia, ataxia
o Hirsutism, gingival hyperplasia, anemia, severe rash
§ HLA-B1502 allele at increased risk of cutaneous rxn (SJS, TEN)
o Potential teratogen
Phenytoin/Fosphenytoin (First Generation AED)
which1st gen anticonvulsant has the most interactions
Phenytoin/Fosphenytoin (First Generation AED)
First line for absence seizures
Ethosuximide
AEs:
o N/V, anorexia, rash, drowsiness, hyperactivity
o Possible agranulocytosis, aggressive behavior
Ethosuximide
pt counseling for ethosuximide
take w/ food/milk to decrease GI upset
Valproic Acid contra
kids <2 yrs
main Valproic Acid interactions
VPA + lamotrigine = increased lamotrigine levels
o Carbamazepine and phenytoin
AEs:
o GI (loss of appetite, nausea, dyspepsia, diarrhea)
§ Reduced by administration w/ food and XR formulation
o Thrombocytopenia (reversible)
o Tremor – alleviated by BB (propranolol)
o Sedation
o Alopecia
o Hepatotoxicity – hepatic necrosis
o Pancreatitis (severe)
o Hyperammonemia
Valproic Acid (
most common AEs of Valproic Acid
GI (loss of appetite, nausea, dyspepsia, diarrhea)
§ Reduced by administration w/ food and XR formulation
o Thrombocytopenia (reversible)
o Tremor – alleviated by BB (propranolol)
o Sedation
valproic acid monitoring
monitoring: thrombocytopenia, LFTs, derm (alopecia)
AEs: hyponatremia, agranulocytosis, aplastic anemia
common: drowsiness, dizziness, ataxia, lethary, confusion, GI upset, hyponatremia
Carbamazepine
Carbamazepine BBW
epidermal necrolysis, SJS, TEN
o Related to gene HLA B1502
monitoring for Carbamazepine
CBC, BMP, dermatologic exams
(2nd Generation)
• Analog of carbamazepine
o Does not cause hematologic adverse effects
o Less drug-drug interactions
Oxcarbazepine
AEs (dose related): diplopia, dizziness, somnolence, hyponatremia
Oxcarbazepine
Mainly used in Lennox-Gastaut Syndrome
Felbamate
AEs (dose related/idiosyncratic): aplastic anemia, hepatotoxicity
o Written consent before giving
Felbamate
AEs: somnolence, abnormal thinking, dizziness, ataxia, weight gain
gabapentin, lyrica
First line in pregnancy
Lamotrigine, Keppra (monitoring req for both)
AEs:
o Maculopapular rash (common)
§ Progresses into SJS
§ Increased risk w/ rapid dose titration, when given w/ VPA, or in peds
lamotrigine
lamotrigine dosing considerations
start low, go slow
counseling for lamotrigine
Lamotrigine reduces efficacy of combined OCPs
AEs: somnolence, dizziness, cognitive slowing, paresthesia, mild blurry vision, altered sense of taste (esp w/
carbonated drinks), inc risk of kidney stones, metabolic acidosis, glaucoma
topamax
indication: infantile spasms
(Vigabatrin)
BBW for Vigabatrin
BBW: PERMANENT VISION LOSS
AEs:
o Common: somnolence, fatigue, dizziness, URI
o Less common: ataxia, asthenia
o Rare: agranulocytosis, SJS, aggressive behavior
Keppra
Zonisamide contra
Sulfonamide derivative (avoid w/ sulfa allergy)
Perampanel abuse potential?
yes, sched 3
Brivaracetam safe in pregnancy?
yes
Avoid the following in absence and myoclonic seizures – can worsen seizure
Carbamazepine
o Oxcarbamazepine
o Gabapentin/pregabalin
o Tigabine
most likely to cause failure of combined OCPs
Carbamazepine
highest risk for malformations in fetus
valproate
Initial Tx of Status Epilepticus
• Lorazepam IV (alternative: diazepam)
o Wait 3 to 5 minutes for response, then additional lorazepam PRN
• If no IV access – midazolam IM
• In second IV: Fosphenytoin OR VPA OR levetiracetam OR Phenytoin
