Antiseizure Drugs Flashcards
MOA of Antiseizure Drugs
Enhancement of GABAergic (Inhibitory) Transmission
Diminution of excitatory (GLUTAMERGIC) transmission
Modification of ionic conductance (Na, K, Ca etc) and presynaptic transmitter release (SV2A)
SODIUM CHANNEL BLOCKERS
blocks voltage gated Na channels – decrease glutamate release
TRICYCLIC
Carbamazepine
Oxcarbazepine
Eslicarbazepine
SE:
SJS
erythematous rash - MC idiosyncratic reaction
diplopia and ataxia
blood dyscrasias - aplastic anemia, agranulocytosis
DOC for TRIGEMINAL NEURALGIA
Carbamazepine
SODIUM CHANNEL BLOCKERS
block Na and Ca channels
decrease glutamate
PHENYLTRIAZINE
Lamotrigine
Zonisamide - only blocks Na channels
SE:
SJS/TEN
SODIUM CHANNEL BLOCKERS
blocks voltage gated Na channels
for generalized tonic clonic, partial seizures, STATUS EPILEPTICUS, migraine, antiarrhythmic (class IB)
HYDANTOINS
Phenytoin Fosphenytoin Mephenytoin Ethotoin Phenacemide
SE: gingival hyperplasia teratogen (fetal hydantoin syndrome) nystagmus - early diplopia and ataxia - MC
Fetal Hydantoin Syndrome
Wide set eyes Upturned eyes Mild midfacial Hypoplasia/broad mandible Long upper lip with thin vermillion border Lower digital hypoplasia
SODIUM CHANNEL BLOCKERS
(-) Na channel high frequency firing of neurons
blocks NMDA, increases GABA levels
DOC for ACUTE MANIA
DOC for GENERALIZED TONIC CLONIC and ABSENCE SEIZURE
BRANCHED CHAIN FATTY ACID
Valproic acid
Sodium Valproate
Divalproex sodium
SE:
teratogen (NTD, spina bifida)
CYP450 inhibitor
GABAERGIC
BARBITURATES
Bind to GABAa receptor sites
Phenobarbital
Primidone
SE:
sedation - most unwanted
acute intermittent porphyria
GABAERGIC
BENZODIAZEPINES
Bind to GABAa receptor subunits to increase frequency of chloride channel opening; membrane hyperpolarization
Diazepam Lorazepam Clorazepate Clonazepam Clobazam
Benzodiazepine used for STATUS EPILEPTICUS
Diazepam
Lorazepam
Clorazepate
Benzodiazepine used for ABSENCE SEIZURES (2nd line)
Clonazepam
Clobazam
CALCIUM CHANNEL BLOCKERS
Decrease calcium current (T type) in thalamus
Ethosuximide
Phensuximide
Methsuximide
DOC for ABSENCE SEIZURES
Ethosuximide
Antiseizure with the greatest number of MOA
Multiple actions on synaptic function via phosphorylation (Na, K, Ca, GABA, AMPA-glutamate, carbonic anhydrase)
for Lennox Gastaut Syndrome and West Syndrome
MONOSACCHARIDE DERIVATIVE
Topiramate
Felbamate
SE:
Urolithiasis
Hematotoxicity – ITP and aplastic anemia
Blocks calcium channels
Decrease glutamate release
for neuropathic pain (postherpetic neuralgia) – 1ST LINE
GABA ANALOGUE
Gabapentin
Pregabalin
