Chapter 14
Antiepileptic Drugs
Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Epilepsy

Seizure


Convulsion


Brief episode of abnormal electrical activity in nerve
cells of the brain
Involuntary spasmodic contractions of any or all
voluntary muscles throughout the body, including
skeletal, facial, and ocular muscles
Epilepsy

Chronic, recurrent pattern of seizures
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Epilepsy (cont’d)

Primary (idiopathic)



Cause cannot be determined
Roughly 50% of epilepsy cases
Secondary (symptomatic)

Distinct cause is identified
• Trauma, infection, cerebrovascular disorder
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Classification of Epilepsy

Generalized onset seizures


Formerly known as grand mal seizures
Partial onset seizures

Simple (formerly known as petit mal seizures)
 Complex
 Secondary generalized tonic-clonic

Unclassified seizures
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Antiepileptic Drugs (AEDs)


Also known as anticonvulsants
Goals of therapy

To control or prevent seizures while maintaining a
reasonable quality of life
 To minimize adverse effects and drug-induced toxicity


AED therapy is usually lifelong
Combination of drugs may be used
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Antiepileptic Drugs (cont’d)


Single-drug therapy started before multiple-drug
therapy is tried
Serum drug concentrations must be measured


Therapeutic drug monitoring
Patients who are seizure free for 1 to 2 years
may be able to discontinue antiepileptic therapy
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Mechanism of Action
and Drug Effects


Exact mechanism of action is not known
Pharmacologic effects:



Reduce nerve’s ability to be stimulated
Suppress transmission of impulses from one nerve to
the next
Decrease speed of nerve impulse conduction within a
neuron
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Antiepileptic Drugs:
Indications




Prevention or control of seizure activity
Long-term maintenance therapy for chronic,
recurring seizures
Acute treatment of convulsions and status
epilepticus
Other uses
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Antiepileptic Drugs: Adverse Effects



Numerous adverse effects—vary per drug
Adverse effects often necessitate a change in
medication
Black box warning as of 2008


Suicidal thoughts and behavior
Long-term therapy with phenytoin (Dilantin) may
cause gingival hyperplasia, acne, hirsutism, and
Dilantin facies
Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
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Classroom Response Question
A patient in a long-term care facility has a new order for
carbamazepine (Tegretol) for seizure management. The
nurse monitors for autoinduction, which will result in
A.
B.
C.
D.
toxic levels of carbamazepine (Tegretol).
lower than expected drug levels.
gingival hyperplasia.
cessation of seizure activity.
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First-Line Antiepileptic Drugs





carbamazepine (Tegretol)
phenobarbital
phenytoin (Dilantin)
primidone (Mysoline)
valproic acid
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Second-Line Antiepileptic Drugs
(Adjunct)






ethosuximide
(Zarontin)
gabapentin
(Neurontin)
lamotrigine (Lamictal)
diazepam (Valium)
clonazepam
(Klonopin)
clorazepate
(Tranxene)






acetazolamide
(Diamox)
levetiracetam
(Keppra)
topiramate (Topamax)
zonisamide
(Zonegran)
tiagabine (Gabitril)
pregabalin (Lyrica)
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Classroom Response Question
The nurse is assessing the current medication list of a
newly admitted patient. The drug gabapentin (Neurontin) is
listed, but the patient states that he does not have any
problems with seizures. The nurse suspects that the patient
A.
B.
C.
D.
is unaware of his own disease history.
has been taking his wife’s medication by mistake.
may be taking this drug for neuropathic pain.
is reluctant to admit to having a seizure disorder.
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Nursing Implications

Assessment

Health history, including current medications
 Drug allergies
 Liver function studies, CBC
 Baseline vital signs
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Classroom Response Question
Before a patient is to receive phenytoin (Dilantin), the nurse
practitioner orders lab work. Which lab result is of greatest
concern?
A.
B.
C.
D.
High white blood cell count
Low serum albumin levels
Low platelet levels
High hemoglobin levels
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Nursing Implications (cont’d)

Oral drugs

Take regularly, same time each day
 Take with meals to reduce GI upset
 Do not crush, chew, or open extended-release forms
 If patient is NPO for a procedure, contact prescriber
regarding AED dosage
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Classroom Response Question
A patient with unstable epilepsy is receiving IV doses of
phenytoin (Dilantin). The latest drug level is 12 mcg/mL.
Which administration technique will the nurse use?
A.
B.
C.
D.
Administer the drug by rapid IV push
Infuse slowly, not exceeding 50 mg/min
Mix the medication with dextrose solution
Administer via continuous infusion
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Nursing Implications (cont’d)

Intravenous forms
Follow manufacturer’s recommendations for IV
delivery—usually given slowly
 Monitor vital signs during administration
 Avoid extravasation of fluids
 Use only normal saline with IV phenytoin (Dilantin)

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Nursing Implications (cont’d)

Teach patients to keep a journal to monitor:






Response to AED
Seizure occurrence and descriptions
Adverse effects
Instruct patients to wear a medical alert tag or ID
AEDs should not be discontinued abruptly
Follow driving recommendations
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Nursing Implications (cont’d)


Teach patients that therapy is long term and
possibly lifelong (not a cure)
Monitor for therapeutic effects


Decreased or absent seizure activity
Monitor for adverse effects




Mental status changes, mood changes, changes in
level of consciousness or sensorium
Eye problems, visual disorders
Sore throat, fever (blood dyscrasias may occur with
hydantoins)
Many others
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Classroom Response Question
Which information will the nurse provide to the patient who
is receiving antiepileptic drug therapy?
A. If you feel sleepy when taking the drug, decrease the
dose by one half
B. Take the drug on an empty stomach
C. Call your health care provider if you experience a sore
throat or fever
D. Patients with epilepsy are not able to hold a job and
work, so you should apply for benefits
Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
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