Mosby items and derived items © 2005, 2002 by Mosby, Inc. CHAPTER 13 Antiepileptic Agents

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

CHAPTER 13

Antiepileptic Agents


Table 13-1 Antiepileptic Drugs of Choice


Epilepsy

• Seizure– Brief episode of abnormal electrical activity in the

brain

• Convulsion– Involuntary spasmodic contractions of any or all

voluntary muscles throughout the body, including skeletal and facial muscles

• Epilepsy– Chronic, recurrent pattern of seizures


Epilepsy (cont'd)

• Primary (idiopathic)– Cause cannot be determined– More than 50% of epilepsy cases

• Secondary– Distinct cause identified

• Trauma, infection, cerebrovascular disorder


Classification of Epilepsy

• Partial seizures– Simple seizures– Complex seizures

• Generalized seizures

• Unclassified seizures

• Status epilepticus


Box 13-1 International Classification of Seizures



• Also known as Antiepileptic Drugs (AEDs)• Goals of therapy

– To control or prevent seizures while maintaining a reasonable quality of life

– To minimize side effects and drug-induced toxicity

• AED therapy is usually lifelong• Combination of agents may be used



• Single-drug therapy started before two-drug and multiple-drug therapy is tried

• Serum drug concentrations must be measured


Mechanism of Action

AED therapy must:– Prevent generation and spread of

excessive electrical discharge from abnormally functioning nerve cells

– Protect surrounding normal cells


Mechanism of Action (cont'd)

• Exact mechanism of action not known• AEDs thought to alter movement of sodium,

potassium, and calcium ions across nerve cells in the brain– Reduce nerve’s ability to be stimulated– Suppress transmission of impulses from one nerve

to the next– Decrease the speed of nerve impulse conduction

within a neuron


Mechanism of Action (cont'd)

• Overall effect– Neurons are stabilized– Neuron hyperexcitability is decreased– The spread of excessive nerve impulses

is decreased


Antiepileptic Agents:Indications

• Prevention or control of seizure activity

• Long-term maintenance therapy for chronic, recurring seizures

• Acute treatment of convulsions and status epilepticus



• Numerous side effects—vary per agent

• Side effects often cause the need to change choice of medication



• Barbiturates, such as phenobarbital (Solfoton)

• carbamazepine (Tegretol)

• valproic acid (Depakote)

• felbamate (Felbatol)

• Hydantoins, such as phenytoin (Dilantin)


Antiepileptic Agents (cont'd)

• Succinimides, such as ethosuximide (Zarontin)

• Benzodiazepines (clonazepam and clorazepate)

• gabapentin (Neurontin)

• lamotrigine (Lamictal)

• Several other miscellaneous agents


Nursing Implications

• Assessment, including– Health history, including current

medications– Drug allergies– Liver function studies, CBC– Baseline vital signs



• Oral agents– Take regularly, same time each day– Take with meals to reduce GI upset– Do not crush, chew, open extended-

release forms



• Intravenous forms– Follow manufacturer’s recommendations

for IV delivery—usually given slowly– Monitor VS during administration– Avoid extravasation of fluids– Use only NORMAL SALINE with IV

phenytoin



• Teach patients to keep a journal to monitor:– Response to AED– Seizure occurrence and descriptions– Side effects

• A medical alert tag or ID should be worn• AEDs should not be discontinued abruptly• Driving may be impaired until drug levels

stabilize



• Patients need to know that therapy is long term and possibly lifelong, not a cure



• Monitor for therapeutic effects– Seizure activity is decreased or absent

• Monitor for side effects– Mental status changes, mood changes, changes

in LOC or sensorium– Eye problems, visual disorders– Sore throat, fever (blood dyscrasias may occur

with hydantoins)– Many others

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Mosby items and derived items © 2005, 2002 by Mosby, Inc. CHAPTER 13 Antiepileptic Agents