Therapeutics - Epilepsy 4

  1. Phenytoin FDA approved Indications:
    • Partial,
    • 1º generalized tonic-clonic, not absence
  2. Phenytoin Adverse effects:
    • Common: CNS, N/V, ataxia, rash
    • Toxic: nystagmus, seizures, coma
    • Long-term: ging. hyperplasia, hirsutism, periph. neuropathy, osteomalacia
    • Rare: SJS, Lupus-like syndrome, bone marrow suppression, hepatotoxicity
  3. Phenytoin Monitoring:
    CBC, LFT’s, levels
  4. Phenytoin Inducer/Inhibitor:
  5. Phenytoin Considerations:
    Not for absence. Use one brand. Measure free levels when interaction suspected.
  6. Pregabalin Primary Mechanism:
    Modulates Ca++ influx by hyper-excited neurons
  7. Pregabalin FDA approved Indications:
    Partial (adjunct)
  8. Pregabalin Adverse effects:
    • Common:
    • Dizzy, somnolence, p. edema, weight gain, vision changes, euphoria
  9. Pregabalin Monitoring:
  10. Pregabalin Inducer/Inhibitor:
  11. Pregabalin Considerations:
    Adjust for renal dysfunction.
  12. What drug is associated with Steven's Johnson Syndrome, and toxic epidermal necrolysis, and should not be used in anyone <16 years of age?
  13. Primidone is a pro-drug of what other anti-epileptic drug?
  14. What advantages does oxcarbazepine have over carbamazepine?
    Not an auto-inducer
  15. Is it necessary to check both primidone and phenobarbital drug levels? Should PEMA levels be checked?
    No, if Primidone is therapeutic, then do not check phenobaritol
  16. What are the therapeutic ranges for Phenobarbitol and Primidone?
    • Phenobarbital 10-40mcg/ml
    • Primidone 5-10mcg/ml
  17. Which anti-epileptic is associated with frequent weight loss?
  18. Which is the only drug approved for both absence seizures and other seizure types?
    Valproic Acid
  19. What is the plasma concentration of valproic acid that must be achieved prior to labeling a therapeutic failure? How does this compare to the "normal" therapeutic range?
    • Normal range: 50-100mcg/ml (Free fraction 4-15mcg/ml)
    • Threshold level for a failure: at least 80mcg/ml
  20. Hair loss is associated with which anti-epileptic drug?
    Valproic Acid
  21. Patients taking zonisamide are at risk if they have an allergy to what?
    Sulfa drugs
  22. What potentially life-threatening side-effects are associated with valproic acid?
    • Rarely:
    • Hepatotoxicity – usually occurs in the first 6 months, not always reversible
    • Thrombocytopenia – may resolve with decreased dose
  23. Tiagabine Primary Mechanism:
    Inhibition of GABA reuptake
  24. Tiagabine FDA approved Indications:
    Partial (adjunct)
  25. Tiagabine Adverse effects:
    Common: nervousness, dizziness, tremor, depression
  26. Tiagabine Monitoring:
  27. Tiagabine Inducer/Inhibitor:
  28. Tiagabine Considerations:
    May only increase dose once weekly to usual range 32-56mg. May take weeks to see effect.
  29. Topiramate Primary Mechanism:
    Modulates Na+ & Ca++ channels, GABA potentiation, inhibits glutamate
  30. Topiramate FDA approved Indications:
    • Partial,
    • 1º generalized tonic-clonic
  31. Topiramate Adverse effects:
    • Common: CNS, memory difficulty, cognitive slowing
    • Long-term use: weight loss, nephrolithiasis
  32. Topiramate Monitoring:
  33. Topiramate Inducer/Inhibitor:
    Inducer (mild) if >200mg/day
  34. Topiramate Considerations:
    Weight loss can be significant. Caution if hx of renal stones. Can cause mental cloudiness (nicknamed “stupamax”). ↑ risk of cleft palate (preg cat. D).
Card Set
Therapeutics - Epilepsy 4
Therapeutics - Epilepsy