Digital PharmD

Informatics in Pharmacy

Seizures: Epilepsy

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*See the seizure medication table  for quick reference.
*Seizure Emergencies

Epilepsy Treatment Options:

Know doses for narrow therapeutic index drugs like phenytoin, but mostly need to know what kind of seizure and major side effects that would cause you to choose a different therapy. Also know REMS programs.

  • Benzos can be used as adjunctive, short-term therapy (clorazepate, clonazepam, diazepam or lorazepam)
  • Brivaracetam
  • Carbamazepine – Beware of Stevens Johnsons syndrome with carbamazepine, induced its own metabolism, pharmacogenomic considerations (HLA-B testing in Asians), blood disorders
  • Eslicarbazepine
  • Ethosuximide – Absence seizures
  • Felbamate in severe, refractory seizures.  Severe side effects: aplastic anemia, liver damage.  Adjunct for Lennox-Gestault
  • Fosphenytoin
  • Gabapentin – Also for peripheral neuropathy
  • Lacosamide – partial onset seizure, increases suicidal ideation
  • Lamotrigine – Adjunct for partial, bipolar, Lennox-Gestault. Valproate inhibits the metabolism (must lower dose).  Carbamazepine induces metabolism.  Titrate to avoid Stephen-Johnson’s syndrome.  Estrogen induces metabolism (increase dose).  Good for patients with sexual dysfunction
  • Levetiracetam – partial and myoclonic, traumatic brain injury, adjust in renal dysfunction
  • Oxcarbazepine – no auto-induction, partial, bipolar, causes hyponatremia, some cross sensitivity with carbamazepine. Good for sexual dysfunction.
  • Perampanel – neuropsychiatric effects
  • Phenobarbital – partial and generalized, not for absence seizures, used for anxiety too.
  • Phenytoin – Dose-related effects include nystagmus, ataxia, drowsiness, cognitive impairment. Non-dose related effects include gingival hyperplasia, hirsutism, acne, rash, hepatotoxicity, coarsening of facial features. Therapeutic range: 10-20 mg/ml.   Michaelis–Menten saturable kinetics, so dose accordingly.
    • Dose titration:
    • < 7 mg – increase 100 mg daily
    • 7-12 increase 50 mg daily
    • > 12 increase by 30 mg or less
  • Pregabalin: reduce dose in renal dysfunction
  • Valproate: good for absence seizures, migraine and partial complex seizures.  Causes neural tube defects, beware in women of childbearing age.  Can increase anemia.
  • Primidone: Metabolized to phenobarbital.  Also used for tremor.
  • Tigabin: Use as an adjunct in partial seizures, may cause seizures
  • Topiramate: Adjunct for partial seizures or Lennox-Gestault. Warning in open-angle glaucoma.
  • Vigabatin: SHARE Rems program.  Causes retinal dysfunction.
  • Zonisamide: Avoid in sulfa allergy, decreases the ability to sweat, increases kidney stones.

*******No Valproic Acid in potentially pregnant patients***********

Also avoid: phenytoin, carbamazepine, and phenobarbital, but not as severely.  Try to use a single agent.

May DC epilepsy meds if:

  1. Seizure free for at least 2 years on medication
  2. Single type of partial or primary seizure
  3. Normal neurological exam and normal IQ
  4. EGG normal

Drugs that can induce seizures: tramadol, FQs, bupropion, imipenem/cilastatin, benzo withdrawal

Electrolytes that can induce seizures: hyponatremia, hypernatremia, hypercalcemia.