Chapter 14

Antiepileptic Drugs

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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

Epilepsy

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Primary (idiopathic) Cause cannot be determined Roughly 50% of epilepsy cases

Secondary (symptomatic) Distinct cause is identified

• Trauma, infection, cerebrovascular disorder

Epilepsy (cont’d)

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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

Classification of Epilepsy

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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

Antiepileptic Drugs (AEDs)

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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

Antiepileptic Drugs (cont’d)

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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

Mechanism of Actionand Drug Effects

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Prevention or control of seizure activity Long-term maintenance therapy for chronic,

recurring seizures Acute treatment of convulsions and status

epilepticus Other uses

Antiepileptic Drugs:Indications

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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

Antiepileptic Drugs: Adverse Effects

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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. toxic levels of carbamazepine (Tegretol).

B. lower than expected drug levels.

C. gingival hyperplasia.

D. cessation of seizure activity.

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carbamazepine (Tegretol) phenobarbital phenytoin (Dilantin) primidone (Mysoline) valproic acid

First-Line Antiepileptic Drugs

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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. is unaware of his own disease history.

B. has been taking his wife’s medication by mistake.

C. may be taking this drug for neuropathic pain.

D. is reluctant to admit to having a seizure disorder.

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Assessment Health history, including current medications Drug allergies Liver function studies, CBC Baseline vital signs

Nursing Implications

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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. High white blood cell count

B. Low serum albumin levels

C. Low platelet levels

D. High hemoglobin levels

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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

Nursing Implications (cont’d)

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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. Administer the drug by rapid IV push

B. Infuse slowly, not exceeding 50 mg/min

C. Mix the medication with dextrose solution

D. Administer via continuous infusion

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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)

Nursing Implications (cont’d)

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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

Nursing Implications (cont’d)

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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

Nursing Implications (cont’d)

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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

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