AEDs Flashcards
“1st line” drugs for partial (focal) seizures
carbamazepine
lamotrigine
levetiracetam
oxcarbazepine
“1st line” drugs for primary generalized tonic-clonic seizures
lamotrigine
levetiracetam
valproate
“1st line” drugs for absence seizures
ethosuximide
valproate
“1st line” drugs for atypical absence, myoclonic, atonic seizures
lamotrigine
levetiracetam
valproate
when should one check [anti-seizure drug]
in AM before next dose
What is the leading cause of tx failure with AEDs
ADRs
titrate up to prevent severe ADRs
AEDs that affect Na+ channels
Carbamazepine oxcarbazepine/eslicarbazepine phenytoin/fosphenytoin lamotrigine lacosamide zonisamide rufinamide
CBZ (carbamazepine) indications
partial and mixed seizures, chronic pain syndromes (trigeminal neuralgia), acute manic/mixed episodes in bipolar I
what is the importance of dosing CBZ
it is an autoinducer so you want to check [CBZ] through 3, 6, 9 weeks (over time may need to increase dose)
cytochrome interactions of CBZ
inducer of 2C9 and 3A4
ADRs of CBZ
sedation/impaired cognition, dizziness/ataxia, blurred or double vision, HA --> may interfere with learning Rash (SJS/TEN/DRESS), vitamin D deficiency, hypocalcemia (osteomalacia) mild hyponatremia (elderly >)
who needs to undergo allelic screening before CBZ is given
- northern Europeans
- pts of Asian ancestry»_space;
CBZ and pregnancy
teratogen
neural tube defects!
Oxcarbazepine/Eslicarbazepine indications
partial seizures
bipolar disorders + neuropathic pain
monitoring for oxcarbazepine/eslicarbazepine
LFTS, serum Na
interactions of oxcarbazepine/eslicarbazepine
CNS depressants
ADRs of oxcarbazepine/eliscarbazepine
similar to CBZ (better tolerated)
more hyponatremia than CBZ
phenytoin/fosphenytoin indications
prevention of “early” seizures following TBI
what is important about dosing of phenytoin
autoinducer
check concentrations 2-3 weeks after initiation and 5-7 days after change
monitoring in phenytoin
VS, CBC, LFTs, Ca2+ and vitamin D
ADRs of phenytoin that are not related to the concentration
gingival hypertrophy**, rash (as with CBZ), vitamin D deficiency/hypocalcemia, drug fever, hepatotoxicity
(less common = hypertrichosis/werewolf, bone marrow suppression, peripheral neuropathy, drug-induced SLE)
ADRs of phenytoin that ARE related to concentration
nystagmus, ataxia, decreased mentation, death
phenytoin/fosphenytoin + pregnancy
teratogen (clefting)
Lamotrigine indications
newly diagnosed absence seizures, LGS, maintenance of bipolar disorder
lamotrigine interactions
VPA increases [lamotrigine] > 2x
lamotrigine ADRs
rash, aseptic meningitis
Lacosamide indications
monotherapy or adjunctive for partial-onset
monitoring of lacosamide
baseline ECG in pts with conduction problems/severe cardiac disease
lacosamide interactions
concomitant PR-prolonging drugs (B-blockers, CCBs)
lacosamide ADRs
neurotoxic - euphoria, small increase in mean PR interval
zonisamide indications
adjunctive for focal seizures
monitoring for zonisamide
BUN/Cr, baseline serum [HCO3]
Zonisamide ADRs
oligohidrosis, hyperthermia, heat stroke
skin reactions (SJS/TEN)
metabolic acidosis/renal stones
neurotoxic ADRs as with CBZ
Rufinamide indications
LGS
monitoring for rufinamide
ECG
rufinamide interactions
additive effect with other drugs that shorten QT interval
AEDs that affect K+ channels
ezogabine
Ezogabine indications
partial-onset seizures (adjunctive)
monitoring of Ezogabine
ECG for QT interval
interactions of Ezogabine
concomitant QT prolongers
ADRs of ezogabine
neuropsychiatric - dizziness, hallucinations
urinary retention - cath?
euphoria
AEDs that affect Ca2+ channels
Ethosuximide
Gabapentin
Pregabalin
Ethosuximide indications
tx of absence seizures
monitoring of ethosuximide
CBC, LFTs
interactions of ethosuximide
CNS depressants
ADRs of ethosuximide
neuropsych - drowsiness, hyperactivity (psychotic behavior)
N/V, bone marrow suppression
Gabapentin indications
partial seizures (adjunct), management of postherpetic neuruopathy, restless leg syndrome
dosing of Gabapentin
300 mg TID with titration
ADRs of gabapentin
somnolence, dizziness (otherwise well-tolerated)
pregabalin indications
fibromyalgia, management of peripheral neuropathies, RLS, off-label for GAD
ADRs for pregabalin
weight gain, euphoria/withdrawl
schedule V
AEDs that modulate GABA activity
phenobarbital clobazam clonazepam tiagabine vigabatrin
phenobarbital indications
partial and secondarily generalized but now has limited use d/t sedating effect
monitoring in phenobarbital
CBC, LFTs, Ca2+ + vitamin D
phenobarbital interactions
induces 2C9 and 3A4
CNS depressants
phenobarbital ADRs
sedation, rash, bone marrow suppression
clobazam indications
LGS (adjunctive)
clonazepam indications
LGS (adjunctive)
tiagabine indications
adjunct for partial seizures
monitoring for tiagabine
CBC, CMP
tiagabine ADRs
new-onset seizures & status epilepticus have been associated with taken for unlabeled indications
Vigabatrin indications
infantile spasms r/t tuberous sclerosis
orphan drug
vigabatrin ADRs
irreversible retinal toxicity
glutamate receptor antagonist AED
perampanel
perampanel indications + ADRs
no vital indications
Schedule III - homicidal ideation/threats
valproate MOA
blocks Na+ channels, acts against T-type Ca2+ currents, increase GABA at clinical doses
valproate indications
mania associated with bipolar depression
migraine prophylaxis
valproate monitoring
LFTs, CBC, serum ammonia
valproate interactions
lamotrigine
valproate ADRs
lethargy, dizziness, tremor, parkinsonism syndrome & cognitive decline
weight gain, hepatotoxicity / hepatic failure (kids have increased risk)
valproate and pregnancy
teratogenicity (*most teratogenic over carbamazepine, phenytoin)
*use only for seizures/bipolar, not migraines
topiramate MOA
blocks Na channels, enhances GABA at a nonBZD on GABA receptors, antagonizes NMDA-glutamate receptor
topiramate indications
migraine prophylaxis, chronic weight management
topiramate monitoring
serum [HCO3] at baseline & q2-4 months recommended
topiramate ADRs
wt loss
oligohidrosis, hyperthermia, heat stroke
carbonic anhydrase inhibitor –> metabolic acidosis/renal stones
dizziness/ataxia, blurred vision/visual disturbances, reversible memory or concentration difficulties
Felbamate indications
LGS
monotherapy & adjunctive therapy for partial seizures & secondarily generalized seizures
felbamate ADRs
fetal aplastic anemia & hepatic failure –> written consent required before therapy
Levetiracetam indications
prevention of early seizures following TBI/NS (replaced phenytoin as gold standard)
levetiracetam monitoring
psychiatric effects (suicidal thoughts, depression)
brivaracetam indications
adjunctive tx of partial onset seizures
brivaracetam monitoring
psychiatric effects (same as levetiracetam) CBC, CMP
cannabidiol indications
seizures associated with dravet syndrome or LGS in pts >2 yrs
cannabidiol interactions
inhibitor of 2C9 & 2C19
cannabidiol ADRs
somnolence, decreased appetite, diarrhea, serum transaminase elevations
monitoring of CBZ
CBC CMP (Na, LFTS, BUN) lipid panel Vit D, calcium UA TFTs pregnancy test