Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. CHAPTER 15 Antiepileptic Drugs

2 Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate 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 and facial muscles  Epilepsy  Chronic, recurrent pattern of seizures

3 Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Epilepsy (cont’d)  Primary (idiopathic)  Cause cannot be determined  More than 50% of epilepsy cases  Secondary (symptomatic)  Distinct cause is identified Trauma, infection, cerebrovascular disorder Trauma, infection, cerebrovascular disorder

4 Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Classification of Epilepsy  Partial-onset seizures  Simple (formerly known as petit mal seizures)  Complex  Secondary generalized tonic-clonic  Generalized-onset seizures  Formerly known as grand mal seizures  Unclassified seizures  Status epilepticus

5 Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. 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

6 Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. 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

7 Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Mechanism of Action  AED therapy must:  Prevent generation and spread of excessive electrical discharge from abnormally functioning nerve cells  Protect surrounding normal cells

8 Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Mechanism of Action (cont’d)  Exact mechanism of action is not known  AEDs are 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 speed of nerve impulse conduction within a neuron

9 Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Mechanism of Action (cont’d)  Overall effect  Neurons are stabilized  Neuron hyperexcitability is decreased  Spread of excessive nerve impulses is decreased

10 Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. 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

11 Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Antiepileptic Drugs  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 may cause gingival hyperplasia, acne, hirsutism, and Dilantin facies

12 Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Antiepileptic Drugs (cont’d)  Barbiturates, such as phenobarbital (Luminal)  carbamazepine (Tegretol)  valproic acid (Depakene)  felbamate (Felbatol)  Hydantoins, such as phenytoin (Dilantin) and fosphenytoin

13 Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Antiepileptic Drugs (cont’d)  Succinimides, such as ethosuximide (Zarontin)  Benzodiazepines (clonazepam and clorazepate)  gabapentin (Neurontin)  lamotrigine (Lamictal)  pregabalin (Lyrica)  levetiracetam (Keppra)  topiramate (Topamax)  tiagabine (Gabitril)  Others

14 Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Nursing Implications  Assessment  Health history, including current medications  Drug allergies  Liver function studies, CBC  Baseline vital signs

15 Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. 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 physician regarding AED dosage

16 Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. 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

17 Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. 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  Driving may be impaired until drug levels stabilize

18 Mosby items and derived items © 2011, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. 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