Phenytoin Indications
1st line - Tonic-Clonic
1st line - status epilepticus prophylaxis
Partial seizures
Phenytoin MOA
Use-dependent Na channel blocker
Inhibits glutamate release
Phenytoin Toxicity
Nystagmus/diplopia/ataxia Sedation Gingival hyperplasia Hirsutism Megaloblastic anemia (decraesed folate absorb) Teratogenic Rash P450 induction Lymphadenopathy Stevens-Johnson syndrome Osteopenia
Carbamazapine Indications
1st line - Tonic-Clonic
1st line - Partial
Carbamazapine MOA
Use-dependent Na channel blocker
Carbamazapine Toxicity
Diplopia/ataxia
Drowsiness
Blood dyscrasias
Teratogen
Ethosuximide Indications
1st line - Absence
Ethosuximide MOA
Reduces low threshold (t-type) thalamic Ca channels
Ethosuximide Toxicity
Gastric distress
Lethargy
Valproic Acid Indications
1st line - Tonic-clonic
Partial
Absense
Myoclonic
Valproic acid MOA
Blocks repetitive firing
Reduce T-type Ca currents
Increased GABA concentraions
Valproic acid Toxicity
GI Weight gain Hair loss Hepatotoxicity Teratogenic
Felbamate Indications
Partial seizures refractory to others
Felbamate MOA
NMDA antagonist (potentiates GABA)
Felbamate Toxicity
Aplastic anemia
Hepatic failure
Gabapentin Indications
Adjunct in partial seizures
Pregabalin Indications
Adjunct in partial seizures
Neuropathic pain management
Pregabalin MOA
Reduce neurotransmitter release
Alpha-2-delta of voltage gated Ca channels
Lamotrigine Indications
Partial
Generalized Tonic-Clonic
Lamotrigine MOA
Blocks repetitive action potentials
Blocks voltage gated Na channels
Lamotrigine Toxicity
Steves-Johnson syndrome
Topiramate Indications
Blocks spread of seizures
*add on in partial
Topiramate MOA
Blocks Na channels
Incrases GABA action
Topiramate Toxicity
Fatigue
Confusion
Nausea
Tiagabine Indications
Partial add-on
Tiagabine MOA
Inhibits GABA reuptake, GAT-1
Tiagabine Toxicity
Dizziness
Tremor
Somnolence
Levetiracetam Indications
Adjunctive in partial
Adjunctive in myoclonic
Adjunctive in generalized tonic-clonic
Levetiracetam Toxicity
Somnolence
Asthenia
Dizziness
Zonisamide Indications
Adjunctive treatment in adults with partial seizures
stops spread
Zonisamide MOA
Reduces voltage-dependent transient inward current (T-type)
Also works at Na channels
Zonisamide Toxicity
Ataxia Anorexia Nervousness Fatigue Speech impairment
Vigabatrin Indications
Adjunctive complex partial
Adjunctive infantile spasms
Vigabatrin MOA
Irreversibly inhibits GABA transaminase (and therefore breakdown)
Vigabatrin Toxicity
Permanent effects on vision (restricted prescribing program)
Clobazam Indications
Adjunctive with Lennox-Gastaut syndrome
*severe epilepsy
Clobazam MOA
Blocks voltage gated Na and Ca channels
Suppresses neuronal hypersynchronization
Inhibits Carbonic anhydrase
Lacosamide Indications
Adjunctive treatment of partial seizures
Lacosamide MOA
Enhances slow inactivation of Na channels