1. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Chapter 14
Antiepileptic Drugs
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2. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Epilepsy
Seizure
Brief episode of abnormal electrical activity in nerve cells of the brain
Convulsion
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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4. 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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5. 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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6. 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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7. 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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8. 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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9. 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
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10. 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
toxic levels of carbamazepine (Tegretol).
lower than expected drug levels.
gingival hyperplasia.
cessation of seizure activity.
Correct answer: B
Rationale: Carbamazepine (Tegretol) is associated with autoinduction of hepatic enzymes. Autoinduction is a process in which, over time, a drug stimulates the production of enzymes that enhance its own metabolism, which leads to lower than expected drug concentrations.
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Elsevier items and derived items © 2009, 2005, 2001 by Saunders, an imprint of Elsevier Inc.

11. First-Line Antiepileptic Drugs
carbamazepine (Tegretol)
phenobarbital
phenytoin (Dilantin)
primidone (Mysoline)
valproic acid
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12. 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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13. 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
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.
Correct answer: C
Rationale: Gabapentin is commonly used to treat neuropathic pain.
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Elsevier items and derived items © 2009, 2005, 2001 by Saunders, an imprint of Elsevier Inc.

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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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15. Classroom Response Question
Before a patient is to receive phenytoin (Dilantin), the nurse practitioner orders lab work. Which lab result is of greatest concern?
High white blood cell count
Low serum albumin levels
Low platelet levels
High hemoglobin levels
Correct answer: B
Rationale: Phenytoin is highly bound to plasma proteins. If serum albumin levels are low, more free drug will be available to exert an effect, and toxicity may occur.
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Elsevier items and derived items © 2009, 2005, 2001 by Saunders, an imprint of Elsevier Inc.

16. 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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17. 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?
Administer the drug by rapid IV push
Infuse slowly, not exceeding 50 mg/min
Mix the medication with dextrose solution
Administer via continuous infusion
Correct answer: B
Rationale: Phenytoin should be mixed only with normal saline, and it should be given by slow IV infusion (but not as a continuous infusion).
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Elsevier items and derived items © 2009, 2005, 2001 by Saunders, an imprint of Elsevier Inc.

18. 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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19. 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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20. 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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21. Classroom Response Question
Which information will the nurse provide to the patient who is receiving antiepileptic drug therapy?
If you feel sleepy when taking the drug, decrease the dose by one half
Take the drug on an empty stomach
Call your health care provider if you experience a sore throat or fever
Patients with epilepsy are not able to hold a job and work, so you should apply for benefits
Correct answer: C
Rationale: To prevent complications, patients should be taught to call the health care provider if they experience fever, sore throat, excessive bleeding or bruising, and new onset of nosebleeds. Drowsiness is a common side effect of these drugs; the dose should never be altered without consulting the prescriber. These medications should be taken with food to decrease GI upset. Most patients with seizure disorders are able to work and are protected by the Americans with Disabilities Act.
Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Elsevier items and derived items © 2009, 2005, 2001 by Saunders, an imprint of Elsevier Inc.