Drugs for Seizures Chapter 15 15

Antidepressant / Anxiolytic Antidepressant / Anxiolytic escitalopram (Lexapro) Tri-Cyclic Antidepressa nt MAOIs Benzodiazepines lorazepam (Ativan) diazepam (Valium) GABA Antagonist A zolpidem (Ambien) Phenytoin-Like Drugs Phenytoin-Like Drugs Succinimides Barbiturates phenobarbital (Luminal) phenytoin (Dilantin) valproic acid (Depakote) ethosuximide (Zarontin) Phenothiazines chlorpromazine (Thorazine) Non- Phenothiazines halperidol (Haldol) Atypical Antipsychotics risperidone (Risperdal) Opioids Opioid Antagonists naloxone (Narcan) morphine (Infumorph) Salicylates aspirin (ASA) NSAIDs ibuprofen (Motrin) Non-Opioid acetaminophen (Tylenol) Central Acting tramadol (Ultram) Anti-Migraine ergotamine (Cafergot) Sumatriptan (Imitrex) OVERVIEW: Neuro System

Antiseizure Pharmacotherapy Goal: suppress neuronal activity enough to prevent abnormal or repetitive firing Drugs act through three mechanisms: Stimulating an influx of chloride ions Delaying an influx of sodium Delaying an influx of calcium Directed at controlling movement of electrolytes across neuronal membranes or affecting neurotransmitter balance Some drugs act by more than one mechanism

Pharmacotherapy Illustrated: Model of the GABA Receptor–Chloride Channel Molecules in Relationship to Antiseizure Pharmacotherapy

Barbiturates and GABA Agents Monitor Patient’s condition Liver and kidney function Pregnancy Category D Common side effects

Patient Teaching Use reliable contraception Immediately report pregnancy Report excessive signs of bleeding Report drowsiness and bone pain

Drugs that Potentiate GABA Action Act by changing the action of gamma-aminobutyric acid (GABA), the primary inhibitory neurotransmitter in the brain Predominate effect of GABA potentiation is CNS depression

Benzodiazepines— Schedule IV Drug Monitor for drug-abuse potential Pregnancy risk—Pregnancy Category D Contraindicated in narrow-angle glaucoma Respiratory depression may result with other CNS depressants. Common side effects include dizziness, drowsiness Overdose—give flumazenil (Romazicon)

Patient Teaching Avoid alcohol, OTC drugs, and herbal medications Avoid nicotine Avoid driving and hazardous activities Rebound seizures if discontinued abruptly Take with food Drug often used illegally

Hydantoin and Phenytoin-like Drugs Monitor serum-drug levels Monitor for signs of toxicity Monitor for blood dyscrasias and bleeding disorders Monitor liver and kidney function Fatal hepatotoxicity can occur

Hydantoin and Phenytoin-like Drugs Contraindications Patients with hypersensitivity to hydantoin products should be cautious. Rash, seizures due to hypoglycemia, sinus bradycardia, and heart block

Patient Teaching Routine labs for serum level Routine labs for liver and kidney function Immediately report signs of toxicity Immediately report unusual bleeding Immediately report liver or brain disease Immediately report heart block, hypoglycemia, or pregnancy

Succinimides Do not abruptly withdraw medication Use with caution with antiseizure medications, phenothiazines, and antidepressants Pregnancy risk—pregnancy Category C

Common Adverse Reactions Drowsiness, headache, fatigue, dizziness Depression or euphoria Nausea, vomiting, weight loss Abdominal pain

Life-Threatening Reactions Severe mental depression with suicide intent Stevens-Johnson syndrome Blood dyscrasias

Patient Teaching Immediately report mood changes or suicidal thoughts Avoid driving and hazardous activities Do not suddenly stop taking Take with food Report symptoms of fever or sore throat Report weight loss and anorexia

Dosage Procedure Start with smallest initial dose Add additional drugs, if necessary Ensure compatibility with other medications Monitor serum-drug levels

Withdrawal of Antiseizure Medications Should be seizure free at least three years Withdraw gradually over several months Resume medications if seizures return Be aware of rebound seizures

Drugs That Potentiate GABA Action Barbiturates Benzodiazepines Miscellaneous GABA agents

Barbiturates Prototype drug: phenobarbital (Luminal) Mechanism of action: changing the action of GABA Primary use: controlling seizures Adverse effects: dependence, drowsiness, vitamin deficiencies, laryngospasm

Prototype Drug: Phenobarbital (Luminal)

Benzodiazepines Prototype drug: diazepam (Valium) Mechanism of action: similar to that of barbiturates but safer Primary use: for short-term seizure control Adverse effects: drowsiness and dizziness

Prototype Drug: Diazepam (Valium)

Diazepam Animation Click here to view an animation on the topic of diazepam.here

Hydantoins Prototype drug: phenytoin (Dilantin) Mechanism of action: to densitize sodium channels Primary use: treating all types of epilepsy except absence seizures Adverse effects: CNS depression, gingival hyperplasia, skin rash, cardiac dysrhythmias, and hypotension

Prototype Drug: Phenytoin (Dilantin)

Phenytoin-Like Drugs Prototype drug: Valproic acid (Depakene) Mechanism of action: to desensitize sodium channels Primary use: for absence seizures Adverse effects: limited CNS depression, visual disturbances, ataxia, vertigo, headache Additional adverse reactions: gastrointestinal effects, hepatotoxicity, pancreatitis

Valproic Acid Animation Click here to view an animation on the topic of valproic acid.here

Prototype Drug: Valproic Acid (Depakene, Depakote)

Succinimides Prototype drug: ethosuximide (Zarontin) Mechanism of action: suppress calcium influx Primary use: for absence seizures Adverse effects: rare but include drowsiness, dizziness, lethargy Very rare but serious side effects: systemic lupus erythematosis, leukopenia, aplastic anemia, Stevens-Johnson syndrome

Prototype Drug: Ethosuximide (Zarontin)

Drugs That Potentiate GABA Action Include barbiturates, benzodiazepines, and miscellaneous GABA agents Suppress the firing ability of neurons

Treating Seizures with Barbituates Low margin for safety High potential for dependence, and they cause Profound CNS depression Overall effective against all major seizure types except absence seizures

Examples of Barbiturates Phenobarbital (Luminal) Amobarbital (Amytal) Secobarbital (Seconal) Pentobarbital (Nembutal)

Treating Seizures with Benzodiazepines Indications include absence seizures and myoclonic seizures Tolerance may develop quickly one of most widely prescribed classes, used also for anxiety, skeletal muscle spasms, and alcohol withdrawal symptoms

Examples of Benzodiazepines Clonazepam (Klonopin) Clorazepate (Tranxene) Lorazepam (Ativan) Diazepam (Valium)

Newer GABA-related Drugs Gabapentin (Neurontin) Pregabalin (Lyrica) Tiagabine (Gabitril) Topiramate (Topamax)

Hydantoin and Newer Drugs Delay an influx of sodium ions across neuronal membranes Sodium movement is factor that determines whether neuron will undergo an action potential Sodium channels are not blocked; they are just desensitized

Treating Seizures With Hydantoins and Related Drugs Useful in treating all types of epilepsy except absence seizures Provides effective seizure suppression, without the abuse potential or CNS depression associated with barbiturates Phenytoin-related drugs used less frequently

Examples of Hydantoins Phenytoin (Dilantin)—most common Fosphenytoin (Cerebyx)

Examples of Phenytoin-like Drugs Carbamazepine (Tegretol)—tonic-clonic and partial seizures Felbamate (Felbatol) Lamotrigine (Lamictal) Valproic acid (Depakene, Depakote)—absence seizures Zonisamide (Zonegran)

Treating Seizures with Succinimides Suppress seizures by delaying calcium influx into neurons Generally only effective against absence seizures Ethosuximide (Zarontin) is the most commonly prescribed drug in this class

Succinimides Examples of succinimides Ethosuximide (Zarontin) Methsuximide (Celontin) Phensuximide (Milontin)

NCLEX-RN Review Question 1 The nurse evaluates patient teaching related to causes of seizures. Further teaching is needed if the patient makes which of the following statements? 1.“Seizures can be caused by inflammation of the brain.” 2.“Seizures can be caused by low blood sugar.” 3.“My relative had seizures because of a large tumor growing in his muscles.” 4.“Seizures may occur after a head injury.”

NCLEX-RN Review Question 1 – Answer 1. “Seizures can be caused by inflammation of the brain.” 2. “Seizures can be caused by low blood sugar.” 3. “My relative had seizures because of a large tumor growing in his muscles.” 4. “Seizures may occur after a head injury.”

NCLEX-RN Review Question 1 – Rationale Rationale: Seizures may be caused by inflammation, head injuries, or low blood sugar levels. Rapid-growing, space-occupying lesions in the brain, which increase intracranial pressure, may cause seizures, but not tumors, within the muscles.

NCLEX-RN Review Question 2 The nursing student asks the nurse to explain the action of the antiseizure medication, phenytoin. The nurse explains the mechanism of action as: 1.Suppression of the influx of chloride into the neuron 2.Stimulation of the influx of calcium into the neuron 3.Suppression of the influx of sodium into the neuron 4.Stimulation of calcium and sodium needed to suppress seizure activity

NCLEX-RN Review Question 2 – Answer 1. Suppression of the influx of chloride into the neuron 2. Stimulation of the influx of calcium into the neuron 3. Suppression of the influx of sodium into the neuron 4. Stimulation of calcium and sodium needed to suppress seizure activity

NCLEX-RN Review Question 2 – Rationale Rationale: The influx of sodium into a neuron enhances neuronal activity. The delay of an influx suppresses neurotransmitter frequency.

NCLEX-RN Review Question 3 The nurse recognizes that several chemicals inhibit neurotransmitter function in the brain. The primary inhibitory transmitter in the brain is: 1.Sodium 2.GABA 3.Chloride 4.Calcium

NCLEX-RN Review Question 3 – Answer 1. Sodium 2. GABA 3. Chloride 4. Calcium

NCLEX-RN Review Question 3 – Rationale Rationale: GABA drugs mimic GABA by stimulating the influx of chloride ions into the neuron, leading to the suppression of neuron firing.

NCLEX-RN Review Question 4 The patient, age 8, is prescribed valproic acid (Depakene) for treatment of a seizure disorder. The nurse should monitor the patient closely for: 1.Hyperthermia 2.Vitamin B deficiency 3.Restlessness and agitation 4.Respiratory distress

NCLEX-RN Review Question 4 – Answer 1. Hyperthermia 2. Vitamin B deficiency 3. Restlessness and agitation 4. Respiratory distress

NCLEX-RN Review Question 4 – Rationale Rationale: Valproic acid may produce an idiosyncratic response in children, including restlessness and psychomotor agitation.

NCLEX-RN Review Question 5 Discharge teaching for a patient receiving carbamazepine (Tegretol) should include: 1.Monitoring blood glucose and reporting decreased levels 2.Expecting a discoloration of contact lenses 3.Immediately reporting unusual bleeding or bruises to the health care provider 4.Expecting a green discoloration of urine

NCLEX-RN Review Question 5 – Answer 1. Monitoring blood glucose and reporting decreased levels 2. Expecting a discoloration of contact lenses 3. Immediately reporting unusual bleeding or bruises to the health care provider 4. Expecting a green discoloration of urine

NCLEX-RN Review Question 5 – Rationale Rationale: Carbamazepine affects vitamin K metabolism and may lead to blood dyscrasias and bleeding.

Pathophysiology Of Seizures / Discussion Pathophysiology Of Seizures / Discussion

Seizures Abnormal or uncontrolled neuronal discharges in the brain Affect Consciousness Motor activity Sensation Symptom of an underlying disorder

Convulsion Involuntary violent spasm of large muscles of face, neck, arms, and legs Not synonymous with seizure

Different etiologies of seizure activity Most common serious neurologic problem affecting children May present as an acute situation, or they may occur on a chronic basis

Known Causes of Seizures Infectious diseases Trauma Metabolic disorders Vascular diseases Pediatric disorders Neoplastic disease

Additional Known Causes of Seizures Medications High doses of local anesthetics Eclampsia Drug abuse Withdrawal syndromes from alcohol or sedative-hypnotic drugs

Pregnancy and Epilepsy Several antiseizure drugs decrease effectiveness of oral contraceptives Most antiseizure drugs are pregnancy category D Eclampsia - severe hypertensive disorder of pregnancy, characterized by seizures, coma, and perinatal mortality

Epilepsy Seizures occurring chronically International Classification of Epileptic Seizures Partial (focal) Generalized Special epileptic syndromes

Seizures in Neonates, Infants, and Children Congenital abnormalities of CNS Perinatal brain injury Metabolic imbalances

Later-Childhood Etiology CNS infections Neurological degenerative disorders Inherited epilepsies

Adult Etiology Cerebral trauma Cerebrovascular disorders Neoplastic disease

Signs and Symptoms of Seizures Related to area of brain with abnormal activity International Classification of Epileptic Seizures: classifies seizures

Simple Partial Seizures Olfactory, auditory, and visual hallucinations Intense emotions Twitching of arms, legs, and face

Complex Partial (psychomotor) Seizures Aura (preceding) Brief period of confusion or sleepiness afterward with no memory of seizure (postictal confusion) Fumbling with or attempting to remove clothing No response to verbal commands

Generalized Seizures Absence (petit mal) Atonic (drop attacks) Tonic-clonic (grand mal)

Absence Seizures Lasting a few seconds Seen most often in children (child stares into space, does not respond to verbal stimulation, may have fluttering eyelids or jerking) Misdiagnosed often (especially in child) as ADD or daydreaming

Atonic Seizures Falling or stumbling for no reason Lasting a few seconds

Tonic-Clonic Seizures Preceeded by aura Intense muscle contraction (tonic phase) followed by alternating contraction and relaxation of muscles (clonic phase) Crying at beginning as air leaves lungs; loss of bowel/bladder control; shallow breathing with periods of apnea; usually lasting 1–2 minutes Disorientation and deep sleep after seizure (postictal state)

Special Syndromes Febrile seizures Myoclonic seizures Status epilepticus

Febrile Seizures Tonic–clonic activity lasting 1–2 minutes Rapid return to consciousness Occurs in children usually between 3 months and 5 years of age

Myoclonic Seizures Large jerking movements of a major muscle group, such as an arm Falling from a sitting position or dropping what is held

Status Epilepticus Considered a medical emergency Continuous seizure activity, which can lead to coma and death

Choice of Drug Depends Upon Type of seizure Patient’s history and diagnostic studies Associated pathologies

Once Medication is Selected Patient placed on low initial dose Amount gradually increased If seizure activity remains, different medication added in small increments Newer antiseizure drugs have less adverse side effects than older drugs Most cases require only a single drug

New FDA Warnings Study included patients with epilepsy, bipolar disorder, psychoses, migraines, and neuropathic pain Popular antiseizure examples found to almost double risk of suicidal behavior and ideation

Drug Therapy for Epilepsy Assessment History of seizure activity Allergies and drug history Knowledge of disease process Knowledge of drug therapy Patient lifestyle

Drug Therapy for Epilepsy (cont'd) Nursing Diagnoses Low Self-Esteem (situational or chronic; related to disease effects) Impaired Social Interaction (related to disease, lack of seizure control) Deficient Knowledge (drug therapy) Risk for Injury (related to seizures or adverse drug effects)

Drug Therapy for Epilepsy (cont'd) Planning Experience therapeutic effects dependent on the reason the drug is given Be free from, or experience minimal, adverse effects. Understanding of disease and drug regimen and purpose Understanding of drug regimen Demonstrate proper self-administration

Drug Therapy for Epilepsy (cont'd) Implementation Monitoring neurological status Ensuring lab values in normal range Patient/family teaching about disease Patient/family teaching about drugs Patient/family teaching about care during seizure activity

Drug Therapy for Epilepsy (cont'd) Evaluation Effectiveness of drug therapy Patient goals

Nursing Process Focus: Patients Receiving Antiseizure Drug Therapy