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

2. Mosby items and derived items © 2005, 2002 by Mosby, Inc. Table 13-1 Antiepileptic Drugs of Choice

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

4. Mosby items and derived items © 2005, 2002 by Mosby, Inc. Epilepsy (cont'd) Primary (idiopathic) –Cause cannot be determined –More than 50% of epilepsy cases Secondary –Distinct cause identified Trauma, infection, cerebrovascular disorder

5. Mosby items and derived items © 2005, 2002 by Mosby, Inc. Classification of Epilepsy Partial seizures –Simple seizures –Complex seizures Generalized seizures Unclassified seizures Status epilepticus

6. Mosby items and derived items © 2005, 2002 by Mosby, Inc. Box 13-1 International Classification of Seizures

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

8. Mosby items and derived items © 2005, 2002 by Mosby, Inc. Antiepileptic Agents Single-drug therapy started before two- drug and multiple-drug therapy is tried Serum drug concentrations must be measured

9. Mosby items and derived items © 2005, 2002 by Mosby, Inc. Mechanism of Action AED therapy must: –Prevent generation and spread of excessive electrical discharge from abnormally functioning nerve cells –Protect surrounding normal cells

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

11. Mosby items and derived items © 2005, 2002 by Mosby, Inc. Mechanism of Action (cont'd) Overall effect –Neurons are stabilized –Neuron hyperexcitability is decreased –The spread of excessive nerve impulses is decreased

12. Mosby items and derived items © 2005, 2002 by Mosby, Inc. Antiepileptic Agents: Indications Prevention or control of seizure activity Long-term maintenance therapy for chronic, recurring seizures Acute treatment of convulsions and status epilepticus

13. Mosby items and derived items © 2005, 2002 by Mosby, Inc. Antiepileptic Agents Numerous side effects—vary per agent Side effects often cause the need to change choice of medication

14. Mosby items and derived items © 2005, 2002 by Mosby, Inc. Antiepileptic Agents Barbiturates, such as phenobarbital (Solfoton) carbamazepine (Tegretol) valproic acid (Depakote) felbamate (Felbatol) Hydantoins, such as phenytoin (Dilantin)

15. Mosby items and derived items © 2005, 2002 by Mosby, Inc. Antiepileptic Agents (cont'd) Succinimides, such as ethosuximide (Zarontin) Benzodiazepines (clonazepam and clorazepate) gabapentin (Neurontin) lamotrigine (Lamictal) Several other miscellaneous agents

16. Mosby items and derived items © 2005, 2002 by Mosby, Inc. Nursing Implications Assessment, including –Health history, including current medications –Drug allergies –Liver function studies, CBC –Baseline vital signs

17. Mosby items and derived items © 2005, 2002 by Mosby, Inc. Nursing Implications Oral agents –Take regularly, same time each day –Take with meals to reduce GI upset –Do not crush, chew, open extended- release forms

18. Mosby items and derived items © 2005, 2002 by Mosby, Inc. Nursing Implications 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

19. Mosby items and derived items © 2005, 2002 by Mosby, Inc. Nursing Implications 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

20. Mosby items and derived items © 2005, 2002 by Mosby, Inc. Nursing Implications Patients need to know that therapy is long term and possibly lifelong, not a cure

21. Mosby items and derived items © 2005, 2002 by Mosby, Inc. Nursing Implications 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