Anticonvulsants

  • Seizures
  • Partial focal, yes or no
  • Simple partial focal no
  • Complex partial focal yes
  • Gen, abs, tonic all ye and yes
  • Absence Seizures
    • Diffuse 3-Hz and wave pattern on EEG
    • Short period of profound impairment with intact body tone
  • Generalized tonic-clonic
    • Abrupt loss of consciousness, stiffening of the muscles, rhythmic jerking of extremities, open eyes during ictus
    • Most fall asleep immediately after seizure and have postictal confusion on awakening

  • Psychogenic nonepileptic seizure (PNES)

    • Conversion disorder, not true seizure
    • Forceful eye closure, side to side body movements, rapid alerting and reorienting, memory recall of seizure
    • NOT associated with abnormal cortical activity, lack post-ictal confusion
    • Intact reflexes, pelvic thrusts
    • Prolactin formal 15-30 minutes after seizure (elevated in epileptic seizure)
    • Video electroencephalogram gold standard, Psychiatric Assessment
    • Lack of epileptiform activity (normal EEG)

  • Barbiturates

  • Phenobarbital
    • MOA: Increases GABAa action
    • SE: Sedation, dependence, Megaloblastic Anemia (Impaired folic acid absorption), Decreases OCP efficacy
  • Pentobarbital
  • Secobarbital
  • Primidone
    • SE: Megaloblastic Anemia (Impaired folic acid absorption)
  • Carbamazepine (Tegretol)
  • MOA: Blocks Na+ channels
  • Anticonvulsant, anticholinergic, antineuralgic, antidiuretic
  • Antiseizure, trigeminal neuralgia, bipolar
  • SE: Decreases T3/T4 (increased deiodination mainly), Decreases OCP efficacy, diplopia, ataxia, blood dyscrasias, liver toxic, SIADH, SJS
  • Ethosuximide (Zarontin)
  • MOA: Blocks thalamic T-type Ca2+ channels
  • USE: Absence seizures only
  • SE: Fatigue, GI distress, Headache, itching, SJS
  • Gabapentinoids
  • Gabapentin (Neurontin)
    • Dose: 100mg TID up to 900mg TID
    • Renally cleared
    • Antacids decrease bioavailability by 20%
    • MOA: Increases GABA and 5HT
    • Use: Add on for seizures only
    • Off-label: sleep, bipolar, migraines, fibromyalgia, anxiety, diabetic and HIV neuropathy
    • SE: somnolence, ataxia, diplopia, dizziness
  • Pregabalin
  • Lacosamide (Vimpat)
  • Lamotrigine (Lamictal)
  • Dose: 12.5mg BID for 2 weeks, 25mg BID for 2 weeks, 50mg BID after
    • Dose doubled w/carbamazepine, phenytoin, phenobarbital
    • Dose every other day with VPA
    • ODT and chewable available
  • MOA: Folate antagonist, voltage gated sodium channel blocker, inhibits 5HT reuptake, inhibits release of glutamate
    • Oral contraceptives decrease Lamictal by 50%
  • Use: Depressive symptoms of bipolar depression (not acute), partial epilepsy, Lennox-Gestalt seizures, Rhett's, Alzheimer's aggression
    • 25-hour half-life
  • SE: Benign maculopapular rash(8%) within 4m ≥ SJS/TEN (0.08%)
    • Worse if \<16 or with VPA
    • Minimal sedation, minimal weight gain, mild dizziness, nausea
    • Disrupts sleep if taken after 5pm
  • Levetiracetam (Keppra)
  • No close monitoring needed
  • SE: Fatigue, drowsiness, headache
    • Exacerbate depression, anxiety, irritability, non-specific psychiatric adverse effects
    • GAD and nervousness, mc in pre-existing anxiety
  • Oxcarbazepine (Trileptal)
  • Dose: 300mg at night up to 600mg BID, no need for food
  • MOA: Monohydroxy metabolite, voltage gated sodium channel blocker
    • Decreased by ETOH and phenytoin
  • Use: Epilepsy, Intermittent Explosive Disorder
  • SE: sedation, nausea, dizziness, vertigo, hyponatremia (3%), decreases OCP efficacy
  • Phenytoin (Dilantin)
  • SE: Megaloblastic Anemia (Impaired folic acid absorption), Decreases T3/T4 (increased deiodination mainly), Decreases OCP efficacy
  • Fosphenytoin (Cerebyx)
  • Tiagabine
  • MOA: Increases GABA by inhibiting reuptake
  • Use: Only focal seizures
  • Topiramate (Topamax)
  • Dose: 25mg at bedtime up to 25mg BID
  • MOA: Increases cerebral GABA
    • Increases phenytoin and VPA
    • CBZ and phenytoin decrease
    • Avoid with acetazolamide
  • Use: Epilepsy, Migraine Prophylaxis, smoking cessation, tremor, bulimia, binge eating, anxiety, weight loss
    • 24-hour half-life, Renally excreted 70%
  • SE: Decreases OCP efficacy, Mixed RTA by inhibiting carbonic anhydrase in proximal and distal tubules, paresthesia, weight loss, sedation, dizziness, word-finding difficulties (≥100mg), Cognitive suppression and sedation that does not improve with time, reduced delayed recall, slow to complete projects
    • Numbness and tingling in fingertips and peripheral extremities (may be improved by QHS dosing)
    • Lowers serum bicarb, Urine pH ≥6 and hypocitraturia, increased risk for calcium phosphate stones and cardiac arrythmias in 1.5%
  • Valproic Acid (VPA)
  • Vigabatrin
  • MOA: Increases GABA, irreversible GABA transaminase inhibitor
  • SE: Permanent visual loss (Black box)
  • Zonisamide (Zonegran)
  • Anticonvulsant Hypersensitivity Syndrome
  • Occurs after recent seizure
  • Can occur with phenytoin, carbamazepine, phenobarbital, lamotrigine
  • Symptoms
    • Fever, rash, lymphadenopathy
  • Labs
    • Eosinophilia
    • Elevated Transaminases