NR-566: Final Exam Study Guide - Week 7 (Seizure Disorders)
Questions with Verified Answers (Correct Update)
Question 1: What are the treatment options for absence seizures?
Answer: traditional: ethosuximide, valproic acid newer: lamotrigine
Question 2: What is the MOA of phenytoin?
Answer: selective inhibition of Na+ channels, slowing the recovery of Na+ channels from an inactive
state back to an active state - suppressing action potentials and activity of seizure-generating neurons
Question 3: How can phenytoin influence the induction of hepatic enzymes?
Answer: 1. stimulates synthesis of enzymes CYP2C8, CYP2CP, CYP3A4 & CYP2B 2. induction of
these enzymes can decrease the effects of OCs, warfarin, and glucocorticoids 3. if doses of phenytoin
are slightly greater than those needed for therapeutic ettects, the liver's capacity to metabolize the drug
will be overwhelmed and l/t a dramatic rise of levels
Question 4: How is the dosage of phenytoin determined?
Answer: serum drug levels, trough levels, & assessment of seizure control
Question 5: What are the therapeutic & prescriptive indications for phenytoin?
Answer: 1. can treat all major forms of epilepsy except absence seziures 2. especially therapeutic for
tonic-clonic seizures 3. drug of choice for adults & older children (carbamazepine is drug of choice for
younger children)
Question 6: What are some major adverse effects 1. CNS noted with phenytoin?
Answer: ettects - nystagmus, sedation, ataxia, diplopia, cognitive impairment 2. gingival hyperplasia -
folic acid can decrease overgrowth 3. dermatologic ettects - SJS, TEN 4. drug reaction w/ eosinophilia
& systemic symptoms (DRESS) - skin eruptions, lymphadenopathy, severe & multi-organ involvement
(hepatic, renal, pulmonary, & hematologic system) 5. dysrhythmias & hypotension when given IV for
status epileptics (SE)
Question 7: What is a genetic consideration regarding phenytoin therapy?
Answer: serious dermatologic ettects and DRESS are associated with the genetic mutation human
leukocyte antigen (HLA)-B*1502 - occurs mostly in Asian descent (test for this genetic mutation before
initiating treatment)
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Questions with Verified Answers (Correct Update)
Question 1: What are the treatment options for absence seizures?
Answer: traditional: ethosuximide, valproic acid newer: lamotrigine
Question 2: What is the MOA of phenytoin?
Answer: selective inhibition of Na+ channels, slowing the recovery of Na+ channels from an inactive
state back to an active state - suppressing action potentials and activity of seizure-generating neurons
Question 3: How can phenytoin influence the induction of hepatic enzymes?
Answer: 1. stimulates synthesis of enzymes CYP2C8, CYP2CP, CYP3A4 & CYP2B 2. induction of
these enzymes can decrease the effects of OCs, warfarin, and glucocorticoids 3. if doses of phenytoin
are slightly greater than those needed for therapeutic ettects, the liver's capacity to metabolize the drug
will be overwhelmed and l/t a dramatic rise of levels
Question 4: How is the dosage of phenytoin determined?
Answer: serum drug levels, trough levels, & assessment of seizure control
Question 5: What are the therapeutic & prescriptive indications for phenytoin?
Answer: 1. can treat all major forms of epilepsy except absence seziures 2. especially therapeutic for
tonic-clonic seizures 3. drug of choice for adults & older children (carbamazepine is drug of choice for
younger children)
Question 6: What are some major adverse effects 1. CNS noted with phenytoin?
Answer: ettects - nystagmus, sedation, ataxia, diplopia, cognitive impairment 2. gingival hyperplasia -
folic acid can decrease overgrowth 3. dermatologic ettects - SJS, TEN 4. drug reaction w/ eosinophilia
& systemic symptoms (DRESS) - skin eruptions, lymphadenopathy, severe & multi-organ involvement
(hepatic, renal, pulmonary, & hematologic system) 5. dysrhythmias & hypotension when given IV for
status epileptics (SE)
Question 7: What is a genetic consideration regarding phenytoin therapy?
Answer: serious dermatologic ettects and DRESS are associated with the genetic mutation human
leukocyte antigen (HLA)-B*1502 - occurs mostly in Asian descent (test for this genetic mutation before
initiating treatment)
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