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Epilepsy & Pharmacology
References: Lilley Pharmacology
&
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2912003/
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History of Epilepsy
 Epilepsy was one of the first brain disorders to be
described in history
 It was mentioned in ancient Babylon more than 3,000
years ago
 Through the ages, the strange behavior caused by
some seizures has led to the creation of numerous
superstitions and prejudices
 The term epilepsy is derived from the Greek word
epilam-banein, meaning to attack or seize.
 People once thought that epileptic individuals were
being visited by demons or gods
 However, in 400 B.C., the early physician Hippocrates
suggested that epilepsy was a disorder of the brain—
and he was right.
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Epilepsy Manifestations
 Seizures can last from a few seconds to a few
minutes…what is an exception?
 Patients and health care professionals do not always
recognize the signs or symptoms, which can include
convulsions, a loss of consciousness, blank staring, lip
smacking, or jerking movements of the arms and legs
 A seizure has a clear beginning, middle, and end.
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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, facial, and ocular muscles
Epilepsy
Chronic, recurrent pattern of seizures
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Epilepsy
Primary (idiopathic)
Cause cannot be determined
Roughly 50% of epilepsy cases
Secondary (symptomatic)
Distinct cause is identified
Trauma, infection, cerebrovascular disorder
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Diagnosis
 Any patient who has a possible seizure disorder
should undergo EEG evaluation as soon as
possible
 Almost all patients with new-onset seizures should
have a brain imaging study to detect any
underlying structural abnormalities
 MRI is superior to CT for detecting cerebral
lesions associated with epilepsy
Seizure Types
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 Partial (focal) seizures
 Simple partial (with motor, sensory, autonomic, or psychic signs;
consciousness is not impaired)
 Complex partial (consciousness is impaired)
 Partial seizures evolving to secondarily generalized seizures
 Primarily generalized seizures
 Myoclonic
 Clonic
 Tonic
 Tonic–clonic (grand mal)
 Atonic
 Absence seizure (petite mal)
 Unclassified seizures
 Neonatal seizures
 Infantile spasms
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Partial Seizures
 Partial- Partial seizures are confined to discrete
areas of the cerebral cortex; only a certain area
of the body is usually involved, at least at the
start
 By contrast, generalized seizures are noted in
diffuse regions of the brain.
 Simple partial seizures cause motor, sensory,
autonomic, or psychic symptoms without an
obvious alteration in consciousness
 These seizures may also be manifested as
changes in somatic sensation (e.g., paresthesias
or tingling), vision, equilibrium, or autonomic
function- olfactory changes, and hearing.
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Partial Seizures Continued
 Complex Partial Seizures are characterized by
focal seizure activity, accompanied by transient
impairment of the patient’s ability to maintain
normal contact with the environment
 Partial seizures can spread to involve both
cerebral hemispheres and may produce a
generalized seizure, usually of tonic–clonic
variety
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Generalized & Absence Seizures
 Generalized: Generalized seizures arise from both
cerebral hemispheres simultaneously
 Absence Seizures (once called petit mal) are
characterized by sudden, brief lapses of consciousness
without loss of postural control.
 The absence seizure typically lasts for only seconds;
consciousness returns as suddenly as it was lost, and
there is no postictal confusion.
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Observation of a
Tonic-Clonic Seizure
 Tonic Seizures
 During a tonic seizure, the person’s muscles initially stiffen and they
lose consciousness. The person’s eyes roll back into their head as the
muscles (including those in the chest, arms and legs) contract and the
back arches. As the chest muscles tighten, it becomes harder for the
person to breathe – the lips and face may take on a bluish hue, and the
person may begin to make gargling noises.
 Many observers have the misconception that the person is in danger of
“swallowing their tongue,” so they attempt to put something in the
person’s mouth. Swallowing your tongue is actually impossible, and
any attempt to open the now tightly clenched jaw may cause more
harm than good.
 Clonic Seizures
 During a clonic seizure, the individual’s muscles begin to spasm and
jerk. The elbows, legs and head will flex, and then relax rapidly at first,
but the frequency of the spasms will gradually subside until they cease
altogether. As the jerking stops, it is common for the person to let out a
deep sigh, after which normal breathing resumes.
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Observation of Seizures
Continued
 Tonic-clonic (once called grand mal) seizures
 A tonic seizure is typically accompanied by a clonic
seizure – it is rare to experience one without the other.
When both are experienced at the same time, this is
known as a tonic-clonic
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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
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Antiepileptic Drugs
Single-drug therapy is usually 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
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Mechanism of Action
and
Drug Effects
Exact mechanism of action is not known
Pharmacologic effects:
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
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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
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Antiepileptic Drugs:
Adverse Effects
 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 (Dilantin) may
cause gingival hyperplasia, acne, hirsutism
 Dilantin facies (if taken during pregnancy- baby
may develop short nose, flat face, large head).
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Classroom Response
Question
A patient in a long-term care facility has a new
order for carbamazepine (Tegretol) for seizure
management. The nurse monitors for autoinduction-enzymes formed that lower drug
concentration) which will result in
A.
toxic levels of carbamazepine (Tegretol).
B.
lower than expected drug levels.
C.
gingival hyperplasia.
D.
cessation of seizure activity.
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A Few First-Line
Antiepileptic Drugs
carbamazepine (Tegretol)
phenobarbital
phenytoin (Dilantin)
primidone (Mysoline)
valproic acid
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Second-Line Antiepileptic Drugs
(Adjunct or supplemental)
 ethosuximide (Zarontin)
 acetazolamide
(Diamox)
 gabapentin (Neurontin)
 levetiracetam (Keppra)
 lamotrigine (Lamictal)
 topiramate (Topamax)
 diazepam (Valium)
 zonisamide (Zonegran)
 clonazepam (Klonopin)
 tiagabine (Gabitril)
 clorazepate (Tranxene)
 pregabalin (Lyrica)
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Medications
 Both new and earlier AEDs are generally equally
effective in new-onset epilepsy
 Newer drugs tend to have fewer adverse effects
 Patients with newly diagnosed epilepsy can begin
treatment with a standard AED (carbamazepine,
phenytoin, valproic acid/divalproex,
phenobarbital) or with a newer agent (gabapentin,
lamotrigine, oxcarbazepine, topiramate)
 The choice depends on each patient’s
characteristics
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Classroom Response
Question
The nurse is assessing the current medication list
of a newly admitted patient. The drug
gabapentin (Neurontin) is listed, but the
patient states that he does not have any
problems with seizures. The nurse suspects that
the patient
A.
is unaware of his own disease history.
B.
has been taking his wife’s medication by mistake.
C.
may be taking this drug for neuropathic pain.
D.
is reluctant to admit to having a seizure disorder.
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Nursing Implications
Assessment
Health history, including current medications
Drug allergies
Liver function studies, CBC
Baseline vital signs
Seizure precautions
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Classroom Response
Question
Before a patient is to receive phenytoin
(Dilantin), the nurse practitioner orders lab
work. Which lab result is of greatest
concern?
A.
High white blood cell count
B.
Low serum albumin levels
C.
Low platelet levels
D.
High hemoglobin levels
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Nursing Implications
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
prescriber regarding dosage
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Classroom Response
Question
A patient with unstable epilepsy is
receiving IV doses of phenytoin (Dilantin).
The latest drug level is 12 mcg/mL. Which
administration technique will the nurse
use?
A.
Administer the drug by rapid IV push
B.
Infuse slowly, not exceeding 50 mg/min
C.
Mix the medication with dextrose solution
D.
Administer via continuous infusion
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Nursing Implications
phenytoin
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 (Dilantin)
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Nursing Implications
 Teach patients to keep a journal to monitor:
 Response to med(s)
 Seizure occurrence and descriptions
 Adverse effects
 Instruct patients to wear a medical alert tag or
ID
 Anti-epileptic drugs should not be
discontinued abruptly
 Follow driving recommendations
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Nursing Implications
 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 dyscrasia may occur (imbalance
of components in blood)
 Many other adverse effects especially with other meds
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Classroom Response
Question
Which information will the nurse provide to
the patient who is receiving antiepileptic
drug therapy?
A.
If you feel sleepy when taking the drug, decrease the dose
by one half
B.
Take the drug on an empty stomach
C.
Call your health care provider if you experience a sore
throat or fever
D.
Patients with epilepsy are not able to hold a job and work,
so you should apply for benefits
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Aura is the term used to describe
symptoms that may occur before a seizure
and may include:
 Visual changes. Examples include:
 Bright lights.
 Zigzag lines.
 Slowly spreading spots.
 Distortions in the size or shape of objects.
 Blind or dark spots in the field of vision
 Hearing voices or sounds (auditory hallucinations)
 Strange smells (olfactory hallucinations).
 Feelings of numbness or tingling on one side of your face or
body.
 Feeling separated from your body.
 Anxiety or fear.
 Nausea
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Case Scenario Patient
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Patient Has a One Year History of Epilepsy -co-workers
observed seizure at work and called 911
Please organize a concept map- also refer to speaker
notes for more information about the patient
1.Admit to neuro unit
2.Code status: Full code
3.Continuous cardiac monitoring and pulse oximetry, maintain 02 sat >94%
4.Neurologic assessment and vital signs every 2 hours
5.Seizure precautions
6.Up as tolerated
7.Start saline lock
8.Regular diet
9. Tegretol 200 mg by mouth 3 times per day
11. Complete blood cell count, magnesium, and basic metabolic panel STAT
12. Valproic Acid level STAT
13. Call provider with laboratory values
14. For seizure activity, administer lorazepam 2 mg IV STAT, may repeat dose
once if initial dose is ineffective; notify provider
15. Give loading dose of fosphenytoin IV 15 mg/kg at a rate of no more than
150 mg/minute