CHAPTER 15
DRUGS FOR SEIZURES
LEARNING OUTCOME 1
Compare and contrast the terms seizures, convulsions, and epilepsy.
Concepts
1. A seizure results from abnormal or uncontrolled neuronal discharges in the brain, which may affect
consciousness, motor activity, and sensation. An electroencephalogram (EEG) can measure the
abnormalities. See Figure 15.1 for examples of EEG recordings. A seizure is considered a symptom of an
underlying disorder, not a disease itself. Known causes of seizures include infectious diseases, trauma,
metabolic disorders, vascular diseases, pediatric disorders, and neoplastic disease. Seizures may also result
from medications, high doses of local anesthesia causing increased stimulation of neurotransmitter or
toxicity, eclampsia during pregnancy, drug abuse, and during withdrawal from alcohol or sedative-hypnotic
drugs.
2. A convulsion refers to involuntary, violent spasms of the large skeletal muscles of the face, neck, arms, and
legs. The term convulsion is not synonymous with seizure.
3. Epilepsy is a disorder characterized by seizures occurring on a chronic basis and is classified by the
International Classification of Epileptic Seizures as partial (focal), generalized, and special epileptic
syndromes.
LEARNING OUTCOME 2
Recognize possible causes of epilepsy.
Concepts
1. Known causes of seizures include infectious diseases, trauma, metabolic disorders, vascular diseases,
pediatric disorders, and neoplastic disease. Seizures may also result from medications, high doses of local
anesthesia causing increased stimulation of neurotransmitter or toxicity, eclampsia during pregnancy, drug
abuse, and during withdrawal from alcohol or sedative-hypnotic drugs.
2. Seizures can also have unknown etiology. Lower tolerance to environmental triggers may cause seizures
when the patient is exposed to sleep deprivation, flickering lights, or fluid and electrolyte imbalances.
3. Congenital abnormalities of the CNS, perinatal brain injury, and metabolic imbalances are usually related to
seizures in neonates, infants, and children.
4. Later-childhood onset of seizures is commonly related to CNS infections or neurological degenerative
disorders.
5. In adults, common causes of the onset of the disorder are cerebral trauma or neoplasm and cerebrovascular
disorders.
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LEARNING OUTCOME 3
Relate signs and symptoms to specific types of seizures.
Concepts
1. Signs and symptoms of seizures are directly related to the area of the brain where the abnormal activity is
occurring. As discussed in the Concepts for Lecture for Learning Objective 1, the International
Classification of Epileptic Seizures identifies types of seizures.
2. Partial (focal) seizures arise in a limited portion of the brain, with the point of origin of abnormal electrical
activity referred to as the abnormal focus or foci. Patients experiencing simple partial seizures often briefly
feel that their current location is vague, and they may hear, see, feel, or smell things that are not present.
Some patients feel very emotional, and some experience arms, legs, or face twitching. Complex partial
seizures result in altered levels of consciousness and symptoms involving sensory, motor, and autonomic
systems. An aura usually precedes the seizure, and patients usually do not follow verbal commands during
the seizure. They often do not remember the seizure.
3. Generalized seizures travel throughout the entire brain. Absence seizures are common in children and last a
few seconds. Symptoms may include staring, transient loss of consciousness, and slight eyelid fluttering or
myoclonic jerks. Symptoms are usually subtle and may be mistaken for daydreaming or attention deficit
disorder. Atonic seizures usually last only a few seconds and are characterized by stumbling or falling for no
apparent reason. Tonic-clonic seizures are the most common type of seizure in every age group and are
usually preceded by an aura. Characteristics of these seizures during the tonic phase include intense muscle
contractions, a hoarse cry at the onset from air being forced out of the lungs, loss of bowel or bladder
control, and shallow breathing or brief periods of apnea. During the clonic phase, patients experience
alternating contraction and relaxation of muscles. Tonic-clonic seizures typically last one to two minutes
and are followed by drowsiness, disorientation, and deep sleep. This postseizure period is called the
postictal state.
4. Special epileptic syndromes include febrile seizures, myoclonic seizures, and status epilepticus. Febrile
seizures usually last one to two minutes with tonic-clonic motor activity and occur in the 3- to 5-year age
group in conjunction with a rapid rise in body temperature. Five percent of all children experience these
seizures. Myoclonic seizures involve large, jerking body movements with major muscle groups contracting
quickly, causing the patient to stumble or fall. These seizures can occur in infants and are not noticed
because the movements are similar to the normal infantile Moro (startle) reflex. Status epilepticus is a
medical emergency that can occur with any type of seizure that is repeated continuously but is most
commonly exhibited with generalized tonic-clonic seizures. The continuous muscle contraction may result
in a compromised airway or hypoxia, hypoglycemia, acidosis, hypothermia, and lactic acid production.
LEARNING OUTCOME 4
Describe the nurse’s role in the pharmacologic management of seizures of an acute nature and epilepsy.
Concepts
1. The role of the nurse is to obtain the previous medical history, diagnostic studies, and pathologic process
that is causing the seizures, because the type of drug the patient is prescribed for control of epilepsy depends
on the type of seizures she is experiencing.
2. Nursing considerations for patients taking barbiturates and miscellaneous GABA agents requires careful
monitoring of the patient’s condition and patient education regarding the medication regimen. Liver and
kidney function should be closely monitored due to the drug’s being metabolized in the liver and excreted in
urine. Patients should be warned that these drugs are pregnancy category D. Depletion of nutrients such as
vitamins D and K is common, especially in the elderly; therefore, the patient should be monitored for
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reduced bone density and bleeding disorders. Common side effects include drowsiness, dizziness, and
postural hypotension. Alcohol and gingko biloba may decrease the antiseizure effect. Patient teaching
should include using reliable contraception; immediate notification if pregnancy occurs; and reporting any
signs of excessive bleeding, such as nosebleeds, black stools, heavy periods, or blood in the urine. In
addition, patients should immediately report severe drowsiness and bone pain. Alcohol should be avoided,
as well as gingko biloba, since they decrease the effects of barbiturates.
3. Nursing considerations for benzodiazepines also involve careful monitoring of the patient’s condition and
education of medication regimen. Benzodiazepines are a Schedule IV drug, so the patient should be
assessed for drug-abuse potential and dependence. These drugs are a pregnancy-risk category D. Since
benzodiazepines change intraocular pressure, patients with narrow-angle glaucoma should not receive these
drugs. Liver and kidney function should also be monitored, and respiratory depression may result if the
patient is taking other CNS depressants. Common side effects include drowsiness and dizziness. If a patient
receives an overdose of benzodiazepines, flumazenil (Romazicon) should be administered to reverse the
CNS depression. IV Valium and Ativan are given for status epilepticus, and oxygen and resuscitation
equipment should be nearby to treat respiratory depression, since flumazenil (Romazicon) should not be
given because of the need to stop the seizures. Do not mix these drugs with others because they tend to
precipitate and are irritating to the veins. Patient teaching should include avoiding alcohol, OTC drugs, and
herbal medications without notifying the prescriber, due to CNS depression. All forms of nicotine should be
avoided because they can decrease the effectiveness of benzodiazepines. Patients should avoid driving or
hazardous activities until they know how they respond to the drug. Rebound seizures may result if the drug
is abruptly stopped. The drug should be taken with food to prevent GI disturbances. patients should be
aware that these drugs are often used illegally as a recre ational drug.
4. Hydantoin and phenytoin-like drugs require serum-drug levels to be monitored to prevent toxicity.
Dizziness, ataxia, diplopia, and lethargy are symptoms of toxicity. Blood dyscrasias and bleeding disorders
should be watched for due to the effect of these drugs on vitamin K metabolism. Hydantoins may increase
blood-glucose levels and cause hematuria. Liver and kidney function may also be affected. Fatal
hepatotoxicity has recently occurred in patients taking valproic acid (Depakene, Depakote) who are also
taking multiple antiseizure drugs, who have existing liver or organic brain disease, or who are under the age
of 2. A history of heart block and seizures due to hypoglycemia are contraindications for hydantoins. They
are pregnancy-risk category D and C drugs. Patient teaching should include ensuring patients understand the
need for routine labs for serum level and liver- and kidney-function tests. Patients should immediately report
signs of toxicity and unusual bleeding and diagnoses of liver or brain disease, heart block, hypoglycemia, or
pregnancy.
5. Nursing consideration for patients taking succinimides includes monitoring of liver and kidney function due
to metabolism and excretion. A health history should assess for other antiseizure medication,
phenothiazines, and antidepressants because these medications may interact with succinimides and result in
a lower seizure threshold and decreased effectiveness of succinimides. Several common adverse reactions
that the patient may experience are drowsiness, headache, fatigue, dizziness, depression or euphoria, nausea
and vomiting, diarrhea, weight loss, and abdominal pain. Life-threatening reactions that occur with these
drugs include severe mental depression with suicide intent, Stevens-Johnson syndrome, and blood
dyscrasias such as leukopenia and agranulocytosis. Symptoms of overdose that the nurse should watch for
are CNS depression, stupor, ataxia, and coma. Serum levels should be monitored. Succinimides are a
pregnancy-risk category C drug. Patient teaching should ensure that the patient understands the need to
immediately report changes in mood, mental depression, or suicidal thoughts. Patients should avoid driving
or hazardous activities and never stop the medication suddenly due to increased chance of rebound seizures.
Succinimides are better tolerated when taken with food to avoid GI effects. Patients should also report
symptoms of fever, sore throat, weight loss, or anorexia.
LEARNING OUTCOME 5
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Explain the importance of patient drug compliance in the pharmacotherapy of epilepsy and seizures.
Concepts
1. Seizure medications are gradually increased from the smallest initial dose possible to control seizure
activity. Additional seizure medications can be added if necessary. The nurse must ensure drug
compatibility prior to administration. Serum-drug levels are necessary to determine therapeutic levels of
medication.
2. If a patient is seizure free for at least three years while on an antiseizure medication, the prescriber may
attempt to withdraw a seizure medication, under close medical supervision. Medications are withdrawn
slowly, over several months, and if any seizure activity occurs, the drug is resumed. The nurse must ensure
that patients understand that abrupt withdrawal of an antiseizure medication may result in rebound seizures.
LEARNING OUTCOME 6
For each of the drug classes listed in Drugs at a Glance, know representative drug examples and explain
their mechanism of drug action, primary actions, and important adverse effects.
Concepts
1. Drugs that potentiate GABA action include barbiturates, benzodiazepines, and miscellaneous GABA agents.
Barbiturates: The prototype drug is phenobarbital (Luminal). The mechanism of action is to change the
action of GABA, which is the primary neurotransmitter in the brain, by stimulating the influx of chloride
ions. This sup presses the firing ability of neurons. The primary use is to control seizures. The adverse
effects include dependence, drowsiness, vitamin deficiencies, and laryngospasm. Benzodiazepines: The
prototype drug is diazepam (Valium). The mechanism of action is similar to that of barbiturates but safer.
The primary use is for short-term seizure control with absence and myoclonic seizures. IV administration is
used to terminate status epilepticus. The adverse effects include drowsiness and dizziness. Miscellaneous
GABA agents: The prototype drug is valproic acid (Depakene). The mechanism of action is similar to that
of barbiturates and benzodiazepines in relation to GABA. The primary use is most often as an adjunct
therapy, and information on these drugs is minimal due to limited use in clinical experience. The adverse
effects include sedation; drowsiness, GI upset, and prolonged bleeding time.
2. Hydantoins and phenytoin-like drugs suppress sodium influx by dampening CNS activity, thus delaying an
influx of sodium ions across neuronal membranes. Hydantoins: The prototype drug is phenytoin (Dilantin).
The mechanism of action is to desensitize sodium channels. The primary use is treating all types of epilepsy
except absence seizures. The adverse effects include CNS depression with excessive dosages, gingival
hyperplasia (which occurs in about 20 percent of patients), skin rash, cardiac dysrhythmias, and
hypotension. Phenytoin-like drugs: The prototype drug is valproic acid (Depakene). The mechanism of
action is to desensitize sodium channels. The primary use is for absence seizures. The adverse effects
include limited CNS depression, visual disturbances, ataxia, vertigo, and headache. Additional adverse
reactions include gastrointestinal effects, hepatotoxicity, and pancreatitis.
3. Succinimides: The prototype drug is ethosuximide (Zarontin). The mechanism of action is to suppress
calcium influx; it works by delaying calcium influx into neurons, which raises the seizure threshold and
thereby suppresses the seizure. The primary use is for absence seizures. The adverse effects are rare, but
drowsiness, dizziness, and lethargy may occur initially. Administering with food can reduce nausea and
vomiting. Very rare but serious side effects include systemic lupus erythematosus, leukopenia, aplastic
anemia, and Stevens-Johnson syndrome.
Prototype Drug

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Diazepam (Valium)
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
Phenobarbital (Luminal)

Phenytoin (Dilantin)

Valproic Acid (Depakane)

Ethosuximide (Zarontin)

adverse effects that their client has experienced.
LEARNING OUTCOME 7
Categorize drugs used in the treatment of seizures based on their classification and mechanism of action.
Concepts
1. Drugs that potentiate GABA action include barbiturates, benzodiazepines, and miscellaneous GABA agents.
These medications work by changing the action of GABA, which is the primary neurotransmitter in the
brain, by stimulating the influx of chloride ions. This suppresses the firing ability of neurons. Barbiturates
include phenobarbital (Lumi nal), amobarbital (Amytal), secobarbital (Seconal), and pentobarbital
(Nembutal). Benzodiazepines given for epilepsy include clonazepam (Klonopin), clorazepate (Tranxene),
lorazepam (Ativan), and diazepam (Valium). Miscellaneous GABA agents are a newer class of antiseizure
drugs and include gabapentin (Neurontin), primidone (Mysoline), tiagabine (Gabitril), and topiramate
(Topamax).
2. Hydantoins and phenytoin-like drugs suppress sodium influx by delaying an influx of sodium ions across
neuronal membranes, thereby dampening CNS activity. These drugs desensitize sodium channels. Sodium
movement is the major factor that determines whether a neuron will undergo an action potential. Hydantoins
in this class include phenytoin (Dilantin) (most common) and fosphenytoin (Cerebyx). Phenytoin-like drugs
include carbamazepine (Tegretol), commonly used for tonic-clonic and partial seizures, felbamate
(Felbatol), lamotrigine (Lamictal), valproic acid (Depakene, Depakote) for absence seizures and zonisamide
(Zonegran).
3. Drugs that suppress calcium influx are succinimides and work by delaying calcium influx into neurons,
thereby suppressing seizures. This raises the seizure threshold. Drugs in this class include ethosuximide
(Zarontin), methsuximide (Celontin), and phensuximide (Milontin).
LEARNING OUTCOME 8
Use the nursing process to care for patients receiving drug therapy for epilepsy and seizures.
Concepts
1. Assessment: Data that the nurse should collect in the assessment phase includes history of seizure activity,
allergies, and drug use in order to avoid interactions; knowledge of disease process and drug therapy; and
lifestyle of the patient.
2. Nursing diagnoses: Possible nursing diagnoses for the patient receiving drug therapy include disturbed
sensory perception related to seizure activity; risk for injury related to seizure activity; deficient knowledge
related to drug therapy and disease process; and noncompliance related to drug, regimen, and necessary
serum lab testing.
3. Planning: During the planning phase of the nursing process, the nurse and patient will set goals for therapy.
Goals that would be included in the care plan include absence of or reduction in the number of seizures; no
injury during seizure activity; understanding of the disease and drug regimen; and compliance with
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necessary serum lab testing.
4. Implementation: Implementation by the nurse for the patient would include monitoring neurological status;
ensuring that lab values of organ function and therapeutic levels of medications are within normal range;
teaching the patient and family about the disease and drug regimen, including possible side effects; and
teaching care during seizure activity.
5. Evaluation of outcome criteria includes evaluating the effectiveness of drug therapy through evaluation of
patient goals.
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