Antiseizure drugs

Question 1

Epilepsy

Answer 1

-seizure disorder resulting from abnormal electric discharges from cerebral neurons
characteristics: loss of consciousness, involuntary, uncontrolled movements
cause: unknown, secondary to brain trauma or anorexia, infection, stroke

Question 2

isolated seizures

Answer 2

can occur due to fever, electrolyte or acid-base imbalance, alcohol, or drugs

Question 3

tonic-clonic seizure

Answer 3

-grand mal
-most common
-generalized alternating muscle spasms and jerkiness

Question 4

absence seizure

Answer 4

-petit mal
-brief loss of consciousness (10 seconds or less)
-usually occurs in children

Question 5

psychomotor

Answer 5

common partial seizure type
-repetitive behavior- chewing or swallowing motions
-behavioral changes
-motor seizures

Question 6

antiseizure drugs

Answer 6

-also called anticonvulsants or antilepileptic drugs
-CNS depressants that: stabalize nerve cell membranes, suppress abnormal electric impulses in cerebral cortex
-prevents seizures but not curative

Question 7

Hydantoins

Answer 7

-inhibit sodium reflex
-reduce repetitive neural firing
-Phenytoin

Question 8

Phenytoin (Dilantin)

Answer 8

-Hydantoin
-contraindications: pregnancy (teratogenic)
-therapeutic serum level: 10-20 mcg/mL
-side effects/ AR- gingival hyperplasia, nystagmus, diplopia, headache, dizziness, slurred speech, alopecia, ventricular fibrillation, depression, suicidal ideation, hyperglycemia, GI distress, urine discoloration, thrombocytopenia, leukopenia, purple glove syndrome, stevens-Johnson syndrome (rash)
-dose is age related
-careful with ambulation

Question 9

Phenytoin drug interactions

Answer 9

-increased effects with cimetidine, isoniazid, chloramphenicol, sulfonamides
-decreased effects with folic acid, antacids, calcium, sucralfate, antineoplastics, antipsychotics, prim rose, ginkgo, borage
-decreased effects of anticoagulants, oral contraceptives, antihistamines, corticosteroids, theophylline, dopamine, cyclosporine, quinidine, rifampin
-LOWERS SEIZURE THRESHOLD=EASIER TO SEIZE

Question 10

Nursing Process: Phenytoin

Answer 10

assessment- obtain a current health history including drugs and herbs used, determine renal and hepatic function lab values
diagnosis- injury, risk for falls (lots of dizziness)
planning- patients seizure frequency will diminish
interventions- monitor serum drug levels of antiseizure drug to determine therapeutic range, warn femal pt of oral contraceptives to use additional contraceptive method , use seizure precautions, advise patients not to drive or perform hazardous activities

Question 11

barbiturates

Answer 11

-phenobarbital
action- enhances GABA activity
use- tonic-clonic, partial, myoclonic seizures, status epilepticus (continuous seizure state)
-therapeutic serum range- 20-40 mcg/ml
-side effects- sedation, tolerance
-discontinuation should be gradual

Question 12

Benzodiazepines

Answer 12

clonazepam- treats absence and myoclonic seizures; tolerance may occur in 6 months
Diazepam- treats status epilepticus, must be administered IV, short term effect (other antiseizure drugs must be given during or immediately after administration of diazepam)

Question 13

Iminostilbenes

Answer 13

-carbamazepine
use- tonic-clonic, partial seizures, psychiatric disorders, trigeminal neuralgia, alcohol withdrawal
therapeutic serum range- 4-12 mcg/ ml
-No grapefruit juice!!!

Question 14

valporate

Answer 14

valproic acid- use for tonic-clonic, absence, and mixed seizures
therapeutic serum range- 50-100 mcg/ ml
se/ae- dizziness, drowsiness, insomnia, diplopia, weakness, GI distress, suicidal ideation, thrombocytopenia, hepatotoxicity

Question 15

antiseizure drugs and pregnancy

Answer 15

-seizure episodes increased in 1/3 of women with epilepsy who are pregnant
-many antiseizure drugs are teratogenic (hypoxia)
-antiseizure drugs tend to inhibit vitamin K- contributes to hemmorhage soon after birth
-antiseizure drugs increase loss of folate (folic acid) in pregnant patients
-needs to be watched, high risk pregnancy

Question 16

antiseizure drugs and febrile seizures

Answer 16

-seizures associated with fever- usually occurs within ages of 3 mos and 5 years
-prophylactic treatment for high-risk patients= phenobarbital or diazepam

Question 17

antiseizure drugs and status epilepticus

Answer 17

-medical emergency
treatment- IV diazepam and Lorazepam, followed by Phenytoin IV
for continued seizures: midazolam, propofol- anesthetic (watch push rate)
-slow iv administration to avoid respiratory depression