Rx:
Meds (Jama 2004;291:615; Nejm 1996;334:165; Med Let 1995;37:37; Ann IM 1994;120:411):
- 1st:
- Carbamazepine (Tegretol) 400-1200 mg qd po (therapeutic level = 6-8 µgm/cc
2 h after last dose and 3 d after last dose change (Jama 1995;274:1622); drug/food interactions: grapefruit increases levels, INH potentiates and is potentiated (Nejm 1982;307:1325); adverse effects: allergic rxns esp associated with certain HLA alleles (Nejm 2011;364:1126, 1134), nystagmus, drowsiness, ataxia, nausea, teratogenic, spina bifida in 1% (Nejm 1991;324:674), agranulocytosis, and aplastic anemia, so get CBC q 1 wk × 6 - Oxcarbazepine (Trileptal) (Med Let 2000;42:33) 300-1200 mg po bid; as effective as carbamazepine and better tolerated, no hematologic hepatic or dermatologic toxicity; does cause ataxia, incr phenytoin levels, interferes w bcp's, phenobarb and phenytoin can decr levels, not affected by erythromycin or cimetidine; $200/mo for 600 mg bid
- Phenytoin (Dilantin) (Grand Mal Epilepsy) and/or
- Valproate 1-3 gm po qd divided (see below)
- 2nd:
- Lamotrigine (Lamictal) (Nejm 2007;369:1000) 50 mg po qd gradually increased to 300-500 mg po qd in bid doses; hepatic metabolism; levels decreased by most other seizure meds but increased by valproate; adv effects: teratogenic, headache, N+V, ataxia, diplopia, rash esp w valproate concomitant use; $175/mo; or
- Phenobarbital 150-250 mg po qd or 0.6 mg/kg at 25-50 mg/min (therapeutic level = 15-30 µgm/cc 3 h after last dose and 20 d after last dose change (Jama 1995;274:1622)); adverse effects: sedation; drug interactions, valproic acid toxicity, in utero intelligence impairment of fetus esp in 3rd trimester (Jama 1995;274:1518); $3/mo; or
- Primidone (Mysoline) 750-1500 mg po qd (therapeutic level = 6-12 µgm/cc); works like and is partly broken down to phenobarbital; or
- Felbamate (Felbatol) (see below)
- Gabapentin (Neurontin) (Nejm 1996;334:1583; Med Let 1994;36:39) 900-1800 mg po qd divided and incr very slowly to avoid intoxication; renal excretion; no interactions with other meds; adv effects: few, fatigue, ataxia, gi; $235/mo; or
- Levetiracetam (Keppra) (Med Let 2000;42:33) 500-1500 mg po bid; adjunctive to other rx; no drug interactions; adv effects: anxiety, somnolence; $200/mo
- Pregabalin (Lyrica) (Med Let 2005;47:73) 75-300 mg po bid; very similar to gabapentin; few drug interactons; adv effects: edema, wgt gain; $120/mo for 75 mg bid
- Topiramate (Topamax) (Med Let 1997;39:52) 200-400 mg po qd; adv effects: mental slowing; $228/mo; or
- Tiagabine (Gabitril) (Med Let 1998;40:45) 4 mg qd to 16 mg tid po; GABA reuptake inhibitor; used as adjunct w others; levels decr by phenytoin, carbamazepine, and phenobarb, but their levels unaffected; $206/mo
- Zonisamide (Zonegram) (Med Let 2000;42:94) 100-600 mg po qd, a sulfa; adv effects: rashes, renal stones, weight loss (Diabetic Ketoacidosis); $115/mo
Surgical resection for refractory and special cases, pursue if 1st-line meds don't work (Jama 1996;276:470, 1996;334:647)