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544 SecTioN iii Neurology aNd Special SeNSeS ` neurology—PhArmACology Neurology aNd Special SeNSeS ` neurology—PhArmACology

` neurology—PhArmACology

Epilepsy therapy
generAliZed
PArtiAl (FoCAl) toniC-CloniC AbsenCe stAtus ePilePtiCus

meChAnism
Sedation, tolerance,
Also for eclampsia seizures (1st
Benzodiazepines **  GABA action side eFFeCts notes
A
✓ dependence, respiratory line is MgSO )
4
depression
Carbamazepine * ✓ Blocks Na channels Diplopia, ataxia, blood 1st line for trigeminal neuralgia
+
✓ dyscrasias (agranulocytosis,
aplastic anemia), liver
toxicity, teratogenesis (cleft
lip/palate, spina bifida),
induction of cytochrome
P-450, SIADH, SJS
Ethosuximide * Blocks thalamic T-type Ca EFGHIJ—Ethosuximide Sucks to have Silent
2+
✓ channels causes Fatigue, GI distress, (absence) Seizures
Headache, Itching (and
urticaria), SJS
Gabapentin ✓ Primarily inhibits high-voltage- Sedation, ataxia Also used for peripheral
activated Ca channels; neuropathy, postherpetic
2+
designed as GABA analog neuralgia
Lamotrigine ✓ ✓ ✓ Blocks voltage-gated Na SJS (must be titrated
+
channels, inhibits the release slowly), hemophagocytic
of glutamate lymphohistiocytosis (black
box warning)
Levetiracetam ✓ ✓ SV2A receptor blocker; Neuropsychiatric symptoms
may modulate GABA and (eg, personality change),
glutamate release, inhibit fatigue, drowsiness,
voltage-gated Ca channels headache
2+
Phenobarbital ✓ ✓ ✓  GABA action Sedation, tolerance, 1st line in neonates
A
dependence, induction (“phenobabytal”)
of cytochrome P-450,
cardiorespiratory depression
Phenytoin, ✓ * *** Blocks Na channels; zero- PHENYTOIN: cytochrome P-450 induction, Hirsutism,
+
fosphenytoin ✓ ✓ order kinetics Enlarged gums, Nystagmus, Yellow-brown skin, Teratogenicity
(fetal hydantoin syndrome), Osteopenia, Inhibited folate
absorption, Neuropathy. Rare: SJS, DRESS syndrome,
SLE-like syndrome. Toxicity leads to diplopia, ataxia, sedation.
Topiramate ✓ ✓ Blocks Na channels,  GABA Sedation, slow cognition, Also used for migraine
+
action kidney stones, skinny (weight prophylaxis
loss), sight threatened
(glaucoma), speech (word-
finding) difficulties
Valproic acid ✓ * ✓  Na channel inactivation, GI distress, rare but fatal Also used for myoclonic
+
✓  GABA concentration hepatotoxicity (measure seizures, bipolar disorder,
by inhibiting GABA migraine prophylaxis
transaminase LFTs), pancreatitis, neural
tube defects, tremor, weight
gain, contraindicated in
pregnancy
Vigabatrin ✓  GABA. Irreversible GABA Permanent visual loss (black Vision gone all bad with
transaminase inhibitor box warning) Vigabatrin
* = Common use, ** = 1st line for acute, *** = 1st line for recurrent seizure prophylaxis.

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