Deck 34: Treatment of Seizure Disorders

Question 1

A patient with partial seizures was on phenytoin and having frequent breakthrough seizures. You switch her to valproic acid and she becomes lethargic with ataxia. The most likely cause:

A) The phenytoin and valproic acid had a synergistic effect
B) Valproic acid adverse effects were taking effect
C) The phenytoin was displaced from plasma proteins and reached toxic levels
D) Valproic acid catalyzed conversion of phenytoin to fosphenytoin
E) None of the above

Answer 1

The phenytoin was displaced from plasma proteins and reached toxic levels

Question 2

The pharmacologic agent of choice for absence seizures is:

A) Diazepam
B) Phenytoin
C) Gabapentin
D) Ethosuximide
E) Phenobarbitol

Answer 2

Ethosuximide

Question 3

The pharmacologic action of phenytoin is:

A) Activation of GABA receptors
B) Blockade of calcium channels
C) Activation of ligand-gated Cl-channels
D) Inhibition of glutamate receptors
E) Blockade of sodium channels

Answer 3

Blockade of sodium channels