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)
- Carbamazepine – Beware of Stevens Johnsons syndrome with carbamazepine, induced its own metabolism, pharmacogenomic considerations (HLA-B testing in Asians), blood disorders
- Ethosuximide – Absence seizures
- Felbamate in severe, refractory seizures. Severe side effects: aplastic anemia, liver damage. Adjunct for Lennox-Gestault
- 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:
- Seizure free for at least 2 years on medication
- Single type of partial or primary seizure
- Normal neurological exam and normal IQ
- EGG normal
Drugs that can induce seizures: tramadol, FQs, bupropion, imipenem/cilastatin, benzo withdrawal
Electrolytes that can induce seizures: hyponatremia, hypernatremia, hypercalcemia.