Drugs Used for Seizure Disorders Chapter 19 Drugs Used for Seizure Disorders Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Chapter 19 Lesson 19.1 Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Objectives Discuss the basic classification systems used for epilepsy Develop a teaching plan for patient education for people diagnosed with a seizure disorder Discuss non-drug treatment of seizures Explain the rationale for proper dental care for people receiving hydantoin therapy Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Objectives (cont’d) Prepare a chart to be used as a study guide that includes the following information: Name of seizure type Description of seizure Medications used to treat each type of seizure Nursing interventions and monitoring parameters for seizures Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Seizure Disorders Symptoms of an abnormality in the nerve centers of the brain Chronic and recurrent seizures point to epilepsy Two broad categories Generalized seizures – affect both brain hemispheres Partial seizures – begin in one hemisphere Epilepsy is the most common of all neurologic disorders. Causes include fever, head injury, brain tumor, meningitis, hypoglycemia, drug overdose or withdrawal, poisoning. Patients may report an aura prior to having a seizure. Sodium and calcium are ions that affect seizure activity within the brain. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Classification of Seizures Generalized convulsive seizures Tonic-clonic (grand mal) Atonic or akinetic Myoclonic Generalized nonconvulsive seizures Absence (petit mal) Partial (localized) Status epilepticus is a medical emergency Tonic-clonic seizures - have a tonic phase, during which sudden intense muscular contractions occur, and a clonic phase, during which bilateral symmetric jerks occur and usually end in a postictal state – or recovery phase of flaccid paralysis and sleep. Atonic seizures - sudden loss of muscle tone and dropping of a limb or slumping to the ground; results in dramatic falls. Myoclonic seizures - lightning-like repetitive contractions of the face, trunk, and extremities. Absence seizures - occur primarily in children and disappear at puberty; involve staring off into space, rhythmic movements of eyes, head, mumbling, chewing, lip smacking. Partial seizures - localized convulsions of single body parts such as a finger or extremity; involves jerking. Status epilepticus - rapidly recurring generalized seizures that do not allow normal functioning between seizures; may result in death. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Teaching Plan for Seizure Disorders Take histories, describe seizures, record postictal behavior Identify a care plan, have proper supplies, discuss with patient and family Assist patient during seizures, observe and record, discuss lifestyle and feelings with patient Encourage patients to maintain medication regimen unless otherwise directed by health care provider Long-term goals for patients are to reduce the frequency of—and injury from—seizures while still having minimal adverse effects from therapy. Perform premedication and ongoing assessments, patient education regarding expectations of therapy, and adverse effects. Monitor serum electrolytes, get a baseline of speech patterns, and determine changes in the degree of orientation and level of alertness. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Patient Education and Health Promotion Exercise and activity Nutrition Safety Stress Oral hygiene Medical considerations Expectations of therapy Fostering health maintenance Written record Difficulty in comprehension Maintain regular activity. Avoid stimulants such as caffeine and limit alcohol. Seizures are known to follow significant intake of alcoholic beverages. Avoid driving or operating power equipment. State laws may prohibit patients with seizures disorders from driving. Gingival hyperplasia (gum overgrowth) has been associated with hydantoins. Maintain daily oral hygiene with frequent gum massage and regular brushing as well as regular dental exams. Carry an identification card or bracelet. Do not discontinue medications unless told to do so by health care provider; inform provider of suspected pregnancy. Discuss expectations of therapy which will involve all aspects of daily life. Explore underlying problems in acceptance of disease. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Non-Drug Therapy for Seizures Surgical intervention can treat refractory seizures Implantable vagus nerve stimulator Ketogenic diet (restricts carbohydrates and protein) Implantable vagus nerve stimulators are approved for children age 12 and older. Ketogenic diet uses fat as the primary fuel of the body; it has been shown to reduce refractory seizures in children who have not experienced effective control with drug therapy. Adverse effects include high lipid levels. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Study Guide Chart Prepare a chart for study with: Seizure type Generalized convulsive Generalized nonconvulsive Describe each category carefully and include all subdivisions Medications used for each type of seizure Benzodiazepines Hydantoins Nursing interventions and monitoring parameters Make chart with: Name of seizure type Description of seizure Medications used to treat each type of seizure Nursing interventions and monitoring parameters for seizures Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Chapter 19 Lesson 19.2 Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Objectives Identify the mechanisms of action thought to control seizure activity when anticonvulsants are administered Cite the desired therapeutic outcomes for seizure disorders Cite precautions needed when administering phenytoin or diazepam intravenously Describe the effects of the hydantoins on patients with diabetes and on people receiving oral contraceptives, theophylline, folic acid, or antacids Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Anticonvulsant Therapy Goals: Reduce frequency of seizure activity Minimize adverse effects of the medicine Selection of drug depends on type of seizure, age and gender of patient, potential adverse effects Anticonvulsants increase seizure threshold Agents either inhibit excitatory processes or enhance inhibitory processes Broad spectrum agents: levetiracetam (Keppra), topiramate (Topamax), valproic acid (Depakene), and lamotrigine (Lamictal). Narrow spectrum agents: phenytoin (Dilantin), carbamazepine (Tegretol), oxcarbazepine (Trileptal), tiagabine (Gabatril), gabapentin (Neurontin), and pregabalin (Lyrica). Before therapy is started, contributing factors of the underlying cause must be identified: head injury, fever, hypoglycemia, drug overdose, etc. Anticonvulsant drugs and antiepileptic therapy are used interchangeably. Prevents seizures from spreading to adjacent neurons. Can be either broad-spectrum or narrow-spectrum agents in relation to their efficacy against different types of seizures. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Drug Class: Benzodiazepines Actions Thought to enhance inhibitory effects of GABA in postsynaptic clefts between nerve cells Uses Anticonvulsant Common adverse effects Sedation, drowsiness, dizziness, fatigue, lethargy; blurred vision Drugs: clonazepam (Klonopin), clorazepate (Tranxene), diazepam (Valium), lorazepam (Ativan) CAUTION: When giving diazepam IV, it must be administered slowly and not mixed with other medications in the same syringe; heart rate must be closely monitored. Therapeutic outcomes: reduced frequency of seizures, reduced injuries, minimal adverse effects from therapy. Serious adverse effects: behavioral disturbances; blood dyscrasias; hepatotoxicity Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Drug Class: Hydantoins Actions Mechanism of action unknown Uses Anticonvulsants to control tonic-clonic seizures Common adverse effects Nausea, vomiting, indigestion; sedation, drowsiness, dizziness, fatigue, lethargy; blurred vision; gingival hyperplasia Serious adverse effects Hyperglycemia; blood dyscrasias; hepatotoxicity; dermatologic reactions Drugs: ethotoin (Peganone), fosphenytoin (Cerebyx), phenytoin (Dilantin) CAUTION: When given IV, phenytoin must be administered slowly and not mixed with other medications in the same syringe. CAUTION: Toxicity may cause nystagmus - involuntary movement of the eyes; often noted as a shaky or wiggly movement. Phenytoin (Dilantin) is the most common hydantoin. Therapeutic drug serum levels must be monitored when taking this drug. Therapeutic outcomes: Reduced frequency of seizures, reduced injuries; minimal adverse effects from therapy. This drug class is particularly effective with grand mal seizures. For patients taking oral contraceptives, spotting and bleeding may indicate reduced contraceptive effects; using alternative forms of birth control is recommended. Theophylline levels may be effected by phenytoin and increased doses may be needed to maintain therapeutic response. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Drug Class: Succinimides Drugs Ethosuximide (Zarontin) Methsuximide (Celontin) Actions Mechanism of action unknown Uses Control absence (petit mal) seizures Common adverse effects Nausea, vomiting, indigestion; sedation, drowsiness, dizziness, fatigue, lethargy Toxic effects of succinimides can be enhanced by antihistamines, alcohol, analgesics, anesthetics, tranquilizers, other anticonvulsants, and sedative-hypnotics. Measures to alleviate common GI adverse effects: gradually increase the dose and give with food or milk to reduce gastric irritation. Therapeutic outcomes: Reduced frequency of seizures, reduced injuries; minimal adverse effects from therapy. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Miscellaneous Anticonvulsants Drug: carbamazepine (Tegretol) Actions Block reuptake of norepinephrine Decrease release of norepinephrine and rate of dopamine and GABA turnover Uses In combination with other anticonvulsants to control tonic-clonic seizures, treat trigeminal neuralgia, treat manic-depressive disorders when lithium not optimal Common adverse effects Nausea, vomiting; drowsiness, dizziness Not effective for myoclonic or absence seizures. Therapeutic outcomes: Reduced frequency of seizures, reduced injuries; minimal adverse effects from therapy. Serious adverse effects: orthostatic hypotension, hypertension; dyspnea, edema; neurologic changes; nephrotoxicity; hepatotoxicity; blood dyscrasias; dermatologic reactions. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Miscellaneous Anticonvulsants (cont’d) Drug: gabapentin (Neurontin) Actions Mechanism of action unknown; does not appear to enhance GABA Uses In combination with other anticonvulsants to control partial seizures, treat postherpetic neuralgia Common adverse effects Sedation, drowsiness, dizziness; blurred vision Serious adverse effects Neurologic changes Drugs enhancing its sedative effect include sleep aids, analgesics, tranquilizers, alcohol. Therapeutic outcomes: Reduced frequency of seizures, reduced injuries; symptomatic relief from postherpetic neuralgia; minimal adverse effects from therapy. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Miscellaneous Anticonvulsants (cont’d) Drug: lamotrigine (Lamictal) Actions Thought to block voltage-sensitive sodium and calcium channels in neuronal membranes Uses In combination with other anticonvulsants to control partial seizures Common adverse effects Nausea, vomiting, indigestion; sedation, drowsiness, dizziness; blurred vision Serious adverse effects Most patients develop skin rash and urticaria Used to treat generalized seizures of Lennox-Gastaut syndrome in pediatric and adult patients. Therapeutic outcomes: Reduced frequency of seizures and injuries; minimal adverse effects from therapy. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Miscellaneous Anticonvulsants (cont’d) Drug: levetiracetam (Keppra) Actions Classified as pyrrolidine derivative; unrelated to other antiepileptic drugs Mechanism of action unknown Uses In combination with other anticonvulsants to treat adult partial-onset seizures Common adverse effects Weakness, drowsiness, dizziness Serious adverse effects Neurologic changes Patients should not operate vehicles or heavy machinery until effects are known. Therapeutic outcomes: reduced frequency of seizures and injuries; minimal adverse effects from therapy. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Miscellaneous Anticonvulsants (cont’d) Drug: oxcarbazepine (Trileptal) Actions Metabolizes into active metabolites of carbamazepine; interacts with sodium, potassium, and calcium ion channels, stabilizing neurons, preventing repetitive firing Uses Monotherapy or combination therapy to treat partial seizures Common adverse effects Confusion, poor coordination, drowsiness, dizziness Therapeutic outcomes: Reduced frequency of seizures and injuries; minimal adverse effects from therapy. Used only as combination therapy in treating partial seizures in children 4 to 16 years of age. Serious adverse effects: nausea, headache, lethargy, confusion, obtundation, malaise; blood dyscrasias. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Miscellaneous Anticonvulsants (cont’d) Drug: phenobarbital (Luminal) Actions Long-acting barbiturate; elevates the seizure threshold, prevents spread of seizure Uses Primarily as alternative when single anticonvulsants are unsuccessful Treat partial and generalized tonic-clonic seizures and generalized myoclonic seizures In combination with other anticonvulsants See Chapter 14 for further discussion Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Miscellaneous Anticonvulsants (cont’d) Drug: pregabalin (Lyrica) Actions Chemically related to gabapentin Does not appear to enhance GABA Uses In combination with other anticonvulsants to control partial seizures Treat pain from fibromyalgia, diabetic neuropathy, and postherpetic neuralgia Common adverse effects Sedation, drowsiness, dizziness; blurred vision Therapeutic outcomes: Reduced frequency of seizures and injuries; symptomatic relief of pain from fibromyalgia, diabetic neuropathy, and postherpetic neuralgia; minimal adverse effects from therapy. Serious adverse effects: neurologic changes; excessive use or abuse Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Miscellaneous Anticonvulsants (cont’d) Drug: primidone (Mysoline) Actions Metabolized into phenobarbital and PEMA, both active anticonvulsants Exact mechanism of action unknown Uses In combination with other anticonvulsants to treat tonic-clonic seizures Common adverse effects Sedation, drowsiness, dizziness; blurred vision Serious adverse effects Blood dyscrasias, paradoxical excitability Structurally related to barbiturates. Therapeutic outcomes: Reduced frequency of seizures and injuries; minimal adverse effects from therapy. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Miscellaneous Anticonvulsants (cont’d) Drug: tiagabine (Gabitril) Actions Mechanism of action unknown; appear to prevent reuptake of GABA into presynaptic neurons, making more GABA available Uses In combination with other anticonvulsants to control partial seizures Common adverse effects Sedation, drowsiness, dizziness Serious adverse effects Neurologic changes, memory loss Therapeutic outcomes: Reduced frequency of seizures and injuries; minimal adverse effects from therapy. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Miscellaneous Anticonvulsants (cont’d) Drug: topiramate (Topamax) Actions Mechanism of action unknown; appears to prolong blockade of sodium channels, enhance activity of GABA, antagonize certain receptors for the neurotransmitter Uses In combination with other anticonvulsants to control tonic-clonic seizures Prevention of migraine headaches Common adverse effects Sedation, drowsiness, dizziness Phenobarbital enhances the metabolism of topiramate. Therapeutic outcomes: Reduced frequency of seizures and injuries; minimal adverse effects from therapy. For patients taking oral contraceptives, spotting or bleeding may be an indication of reduced contraceptive activity. Recommend alternative methods of birth control. Serious adverse effects: neurologic changes, hydration status; decreased sweating and overheating have been reported. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Miscellaneous Anticonvulsants (cont’d) Drug: valproic acid (Depakene) Actions Appear to support GABA activity as an inhibitory neurotransmitter Uses Control tonic-clonic seizures Only single-drug therapy to treat combination of generalized tonic-clonic, absence, or myoclonic seizures Treat acute mania of bipolar disorder Common adverse effects Nausea, vomiting, indigestion; sedation, drowsiness, dizziness; blurred vision One metabolite of valproic acid is a ketone, which may cause a false-positive on urine tests for ketones. Liver function and serum therapeutic drug levels should be monitored when taking this drug. Therapeutic outcomes: Reduced frequency of seizures and injuries; minimal adverse effects from therapy. Serious adverse effects: blood dyscrasias; hepatotoxicity; pancreatitis. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Miscellaneous Anticonvulsants (cont’d) Drug: zonisamide (Zonegran) Actions Block sodium and calcium channels to stabilize neuronal membranes Uses In conjunction with other anticonvulsants to control adult partial seizures Common adverse effects Drowsiness, dizziness Serious adverse effects Neurologic changes, nephrotoxicity, blood dyscrasias, dermatologic reactions Classified as a sulfonamide. Phenobarbital enhances the metabolism of zonisamide. Therapeutic outcomes: Reduced frequency of seizures and injuries; minimal adverse effects from therapy. Determine if patient has allergies to sulfonamides or a history of skin rashes. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.