Conditions Effecting the Nervous System and PharmacotherapyPart Three: Seizures Flashcards
Exam 3
Seizure Disorders & Epilepsy:
What are seizures?
Transient, sudden, uncontrolled discharge of neurons of the cerebral cortex interferes with normal function
Seizure Disorders & Epilepsy:
What changes occur with seizures?
What is something abnormal that occurs?
Physical or behavior △
Abnormal brain electrical activity
Seizure Disorders & Epilepsy:
What is a seizure disorder?
Epilepsy
Seizure Disorders & Epilepsy:
What is epilepsy? What are symptoms?
Recurrent unpredictable seizures
Sx: brief pds unconsciousness –> violent convulsions
Convulsions: jerking movements
Seizure Disorders & Epilepsy:
What are seizures initiated by?
Group of hyperexcitable neurons ~ focus
Seizure Disorders & Epilepsy:
What do neurons do in seizures?
How are neurons?
Neurons fire frequently with greater amplitude
Hypersensitive, easily activated by triggers
Seizure Disorders & Epilepsy:
Neurons are Hypersensitive, easily activated by triggers like what?
Hypoxia, hypoglycemia, hyponatremia, sensory stimulation
Seizure Disorders & Epilepsy:
Neurons are Hypersensitive, easily activated by triggers- why?
Results from hypoxia at birth, head trauma, brain infection, stroke, cancer, genetic disorders
Seizure Disorders & Epilepsy:
What kind of shift occurs?
Discharge from focus –> brain recruiting other neurons
Depolarization shift (Na+/K+/Ca+)
Seizure Disorders & Epilepsy:
Epilepsy patho: What can lead to this?
Genetic mutations & environmental effects
Seizure Disorders & Epilepsy:
Epilepsy patho: What are abnormalities?
Abnormalities in synaptic transmission, imbalance in brain’s excitatory & inhibitory NT
Development of abnormal nerve connections, loss of nerves after injury
Seizure Etiology
Idiopathic:
Acquired: secondary cause, cerebral damage (eg head trauma most common cause)
Prenatal causes: exposure to radiation, drugs in utero during 1st trimester, Pre-eclampsia, L&D, O2 deprivation
Congenital cerebral malformations/ genetic syndromes
Infants or young children with high fevers
Brain Infection
Space-occupying lesions/hemorrhage
Anoxia
Hypoglycemia
Cerebral edema
Degenerative brain disorders
CVAs
Ingesting toxic substances
Metabolic disturbances, electrolyte disorders
Drugs that lower seizure threshold/alcohol
NT: Glutamate vs γ-Aminobutyric acid (GABA)
Seizure Complications
Brain damage
TBI
Aspiration
Mood disorders
Status epilepticus
Risk of injury that may occur during violent shaking during a tonic-clonic grand mal seizure.
Precipitating Factors of Seizures:
Who can have a seizure?
Anyone can have a seizure
Precipitating Factors of Seizures:
Seizures can be triggered by environmental factors.
Loud noises and bright lights can bring on seizures, as well as biochemical stimuli and fluid retention.
Changes in medication, electrolytes or hypoventilation can bring on a seizure in an individual predisposed to seizures.
Hypoglycemia, lack of sleep, stress, drugs (withdrawal), women before menses
If someone is aware of precipitating factors that cause seizures what can they do?
A person with a seizure disorder, or who has a history of seizures, can avoid potential precipitating factors if they are aware of them.
Pathophysiology of Seizures:
When electrical impulses are discharged from different foci, or disorganized, abnormal motor and sensory activity result, along with a possible loss of consciousness.
Pathophysiology of Seizures:
How long do seizures last? What would effect them?
Seizures can last a few seconds or several minutes, depending on the extent of the neurons involved.
Pathophysiology of Seizures:
What can be used to determine the focus of activity and type of seizure?
EEG can determine the focus of the activity and the type of seizure.
Pathophysiology of Seizures:
During seizures, what is depleted?
During seizure, more O2 & glucose consumed & rapidly depleted
Pathophysiology of Seizures:
During seizures, what is accumulating?
What can this lead to?
Lactate accumulates in brain tissue
Can cause progressive brain injury/damage
Pathophysiology of Seizures:
What can clinical manifestations be used to determine?
What are clinical manifestations dependent on?
can also help determine the sz type.
Descriptions of onset of symptoms by witnesses can be beneficial in identifying the focus and type.
Sx depend on seizure focus & neuron connections to the focus
Classification: Partial Seizures
Where do they originate from?
Originating in one area of the brain (single or focal origin)
Classification: Partial Seizures
How do they spread?
Very limited spread to adjacent areas
What is a type of partial seizure?
Simple Partial (focal)
Complex partial (focal)
Simple Partial (focal): What can it be confused with?
Easily confused with other DX ~ migraines, syncope, psychiatric disorders
Simple Partial (focal): What is the focus of it?
Epileptogenic focus, related to a single area of damage in the cerebral cortex
Simple Partial (focal): What can occur before seizure happens? Epileptogenic focus, aka?
AKA an aura - Unusual sensation just before impending seizure when they precede more significant seizure activity
Classification: Partial Seizures
AKA an aura - Unusual sensation just before impending seizure when they precede more significant seizure activity
What does not occur with Simple Partial seizures?
⍉ loss of consciousness ~ persists for 20-60s
What are discrete symptoms of simple partial seizures?
Discrete symptoms:
Motor: twitching thumb, jerking movements in specific part of body
Sensory: numbness & visual, auditory, olfactory hallucinations
Autonomic: nausea, flushing, salivation, urinary incontinence
Psychoillusory: feelings of unreality, fear, depression, unexplained feelings of joy, sadness
Complex partial (focal)
What occurs during it?
Impaired consciousness & memory, lack of responsiveness ~ 45-90s
Complex partial (focal)
How do these seizures start? Then what happens?
Onset: motionless, fixed gaze then –> Automatism
Automatism:
repetitive, purposeless movements, lip smacking, blinking, hand wringing, circling, repeating phrases, clapping hands (multiple body parts affected)
Complex partial (focal)
What kind of experience is it?
Produces a dream-like experience
Complex partial (focal)
Where does it originate?
Originates in temporal lobe, frontal lobe, or limbic system
What may be present in Complex partial (focal) seizures?
What does it effect?
An aura or hallucination may be present, or sensation of déjà vu
Affects larger area of brain
Manifestations of focal seizures depend on ____
region of brain involved
Read slide 9
Classification: Generalized Seizures
What kind of activity occurs?
Are they convulsive or not?
What occurs immediately?
Abnormal activity on both sides of brain
May be convulsive or nonconvulsive
Immediate loss of consciousness
Classification: Generalized Seizures
What are the types?
Tonic-clonic (formerly grand mal)
Absence (petit mal)
Status epilepticus
Peds
Classification: Generalized Seizures
Tonic-clonic (formerly grand mal)
What are actions of patient?
Major convulsions –> loud cry –> forceful air expiration
Classification: Generalized Seizures
Tonic-clonic (formerly grand mal)
What happens to muscles?
Muscle rigidity (tonic phase) –> synchronous bilat jerks & shaking (clonic phase)
Classification: Generalized Seizures
Tonic-clonic (formerly grand mal)
How is consciousness? Urine continence?
Urine incontinence
Impaired consciousness –> CNS depression (postictal)
Classification: Generalized Seizures
Absence (petit mal)
Who does it occur in primarily? When does it stop?
Primarily peds, cessation typical by early teens
Classification: Generalized Seizures
Absence (petit mal)
What kind of activity occurs?
Brief LOC ~ 10-30s, hundreds/day
Mild, symmetric motor activity ~ eye blinking
Or ⍉ motor activity at all
Classification: Generalized Seizures
Status epilepticus: How long does it last?
≥ 15-30min
Classification: Generalized Seizures
Status epilepticus: What is it a series of?
How is consciousness?
Series of recurrent sz
No regain of consciousness
Generalized convulsive SE ~ life threatening
Classification: Generalized Seizures
When do seizures occur in Peds? What age is it common?
What occurs at that time?
What occurs for short periods?
Febrile
Common in peds 6m – 5yo
Short periods of generalized tonic-clonic
Atonic
Classification: Generalized Seizures
Peds: Atonic- What occurs?
Sudden loss of muscle tone
“Head drop” collapse
Myoclonic: what happens and when does it occur?
Jerking of arms, shoulder and head
Episodes typically occur soon after awakening?
Tonic-Clonic: What happens?
Look at picture
Three main phases of seizures:
Clinical Manifestations
Preictal Phase
Ictal
Postictal Phase
Three main phases of seizures:
Clinical Manifestations
What is part of the preictal phase?
Prodroma
Aura
Three main phases of seizures:
Clinical Manifestations
Preictal Phase: What are Clinical Manifestations during prodroma?
Early clinical manifestations:
Malaise
HA
Depression,
alterations in smell, taste, vision, hearing
can occur days to hours before seizure
Three main phases of seizures:
Clinical Manifestations
Preictal Phase: When do symptoms of prodroma phase occur?
Sx occur hours –> days prior to sz
Three main phases of seizures:
Clinical Manifestations
Preictal Phase: What occurs during aura?
A funny feeling
peculiar sensations
Three main phases of seizures:
Clinical Manifestations
Ictal Phase: What is it?
The event of the seizure
Three main phases of seizures:
Clinical Manifestations
Ictal Phase: What are the parts to the ictal phase?
Tonic phase
Clonic phase
Three main phases of seizures:
Clinical Manifestations
Ictal Phase: What occurs during Tonic phase?
A state of muscle contraction in which there is excessive muscle tone
Three main phases of seizures:
Clinical Manifestations
Ictal Phase: What occurs during Clonic phase?
A state of alternating contraction and relaxation of muscles
Three main phases of seizures:
Clinical Manifestations
Ictal Phase: How do symptoms range in ictal phase?
sx range from amnesia, pupils dilate, diaphoresis, cyanosis, frightened, crying, laughing, violent, angry behavior, incontinence
Three main phases of seizures:
Clinical Manifestations
Postictal Phase: How do symptoms range in ictal phase?
Sx: h/a, confusion, post seizure CNS depression, confusion, fatigue, deep sleep, memory loss
Three main phases of seizures:
Clinical Manifestations
Postictal Phase: When it is?
Time period immediately following cessation of seizure activity
DX of seizures how?
PMH
PE
Head CT, MRI, PET
Electroencephalogram
Lumbar puncture –
Labs
EKG
Dx seizure: What may Scans reveal?
What may Electroencephalogram reveal?
What does lumbar puncture reveal?
What does labs and EKG reveal?
Head CT, MRI, PET ~ may reveal trauma
Electroencephalogram ~ essential for DX & to localize focus
Lumbar puncture – infection
Labs – r/o metabolic disturbances
EKG – r/o cardiac dysrhythmias
Classification: Generalized Seizures
What is treatment done before a seizure?
Prevention
Medical-alert bracelet
Avoid precipitating factors
Sleep deprivation, EtOH, illicit drugs, Excessive stimuli
Pharm: AEDs/anticonvulsants
Classification: Generalized Seizures
What is drug treatment done before a seizure?
Pharm: AEDs/anticonvulsants
Classification: Generalized Seizures
What is treatment done during a seizure?
position the individual on their side
protect head
⍉ forcing items b/w teeth
⍉ restrain(ts)
Manage airway, O2
Time the event & describe nature of event (eg – aura, muscle twitching, LOC, incontinence)
Ensure all pts with seizures/epilepsy have
IV access
Generalized seizure: Treatment- what drug class for during a seizure?
Pharm: Benzodiazepines
Classification: Generalized Seizures
What is treatment done after a seizure?
Allow them to rest
AEDs (anti-epileptics)
Antiepileptic Drug (AED) Classification
AKA anticonvulsants
What are traditional AEDs?
Phenytoin
Carbamazepine
Valproic acid VPA
Phenobarbital
Antiepileptic Drug (AED) Classification
AKA anticonvulsants
What are newer AEDs?
Gabapentin
Levetiracetam
Topiramate
Lamotrigine
Antiepileptic Drug (AED) Classification
AKA anticonvulsants
What is a third group of drugs?
Benzodiazepines
ending in “pam”
Antiepileptic Drugs AEDs:
What effects do they have (what do they suppress)?
Suppress discharge of neurons within seizure focus
Suppress spread of seizure activity from the focus to other areas of the brain
Antiepileptic Drugs AEDs:
AEDs act through 4 basic mechanisms:
(But list 5 things)
Blockade of sodium channels
Blockade of calcium channels
Blockade of receptors for glutamate (an excitatory neurotransmitter)
Potentiation of GABA (an inhibitory neurotransmitter).
Suppression of K influx
Antiepileptic Drugs AEDs:
AEDs act through 4 basic mechanisms:
Suppress Na influx/Promote K+ efflux:
Na entry thru gated pores cell membrane –> Action Potentials
Channel must be in activated state for sodium influx
Binding to inactivated Na channels
Prolong inactivation ~ ↓ firing @ high frequency
Na in depolarization
K out repolarization (some drugs work here – promote K efflux – prolong repolarization)
Antiepileptic Drugs AEDs:
AEDs act through 4 basic mechanisms:
Ca:
Influx of Ca –> transmitter release
Certain drugs block channels, transmission suppress
Antiepileptic Drugs AEDs:
AEDs act through 4 basic mechanisms:
Glutamate: What is it? What does it do?
Glutamate ~ excitatory NT
Glu –> X –> NMDA receptors (works here)
Suppress neuronal excitation
Antiepileptic Drugs AEDs:
AEDs act through 4 basic mechanisms:
GABA: What is it?
GABA ~ inhibitory NT in brain
Antiepileptic Drugs AEDs:
AEDs act through 4 basic mechanisms:
GABA: What does it do?
↓ neuronal excitability & suppress seizure activity
Antiepileptic Drugs AEDs:
AEDs act through 4 basic mechanisms:
GABA: ????????
Direct binding to receptors to GABA receptors
Benzodiazepines & barbiturates
Antiepileptic Drugs AEDs:
AEDs act through 4 basic mechanisms:
GABA: Promotion of GABA release is by?
Promotion of GABA release
Gabapentin
Antiepileptic Drugs AEDs: What are the goals of these drugs?
Reduce seizures to restore QOL
Balance b/w control & ADEs
Antiepileptic Drugs AEDs cont: How is drug treatment?
Drug TX is highly individualized
Antiepileptic Drugs AEDs cont: What is done to determine AED that should be used?
Several AEDs may be tried before
AEDs are selective for certain seizure d/o
Must match sz type with drug
Good history taking/EEG
Trial period
Antiepileptic Drugs AEDs cont.
What is the order in which drugs are used?
Initial TX ~ one AED
Failure of initial TX
D/C 1st agent & start 2nd agent
2nd failure
3rd AED alone (not used prior) as mono-TX
Or- AED combo
Antiepileptic Drugs AEDs cont.
Drug evaluation & adherence
Antiepileptic drug (AED) trial period
No guarantee seizure will be controlled
Antiepileptic Drugs AEDs cont.
Patient & family ed
Avoid hazardous activities until control achieved
Chronic nature of disease
Importance of adhering to regimen
Seizure frequency chart/record events
Antiepileptic Drugs AEDs cont.:
What should be monitored? Why?
Monitoring plasma levels
Evaluate adherence
Determine cause of lost seizure control
Identify cause of toxicity in pts taking > 1 drug
Antiepileptic Drugs AEDs cont.
Withdrawal: How should meds be withdrawn?
May go into remission
⍉ guidelines indicating appropriate time to D/C
Slow taper ~ 6w to several months
D/C sequentially, ⍉ simultaneously
Failure to gradually reduce –> freq cause of SE
Antiepileptic Drugs AEDs cont.
What effect do these drugs have on oral contraceptives?
So what must you have?
↓ Oral Contraceptive efficacy
Backup birth control
Antiepileptic Drugs AEDs cont.
What are oral contraceptives considered?
Oral contraceptives are inducers= the med is metabolized quickly
Antiepileptic Drugs AEDs cont.
What do they do to CNS? So what should you do?
CNS depression
Avoid hazardous activities until control achieved
Risk ↑ w/ concurrent depressants
⍉ EtOH consumption
Antiepileptic Drugs AEDs cont.
How do these drugs effect fetus? What should be done?
What should be done to avoid problems for fetus?
Teratogenic
Benefit > risk
Avoid all traditional (some newer AEDs)
Folic acid for prevention
Antiepileptic Drugs AEDs cont.
Suicide risk: How common?
May be lower than previously believed
Rare, ONLY certain AEDs NOT all
Higher risk when taken for epilepsy vs other conditions
Potential relation of psyc illness from epilepsy > medication
Pt & family ed to report warning sx
Screen all pts
Use of AEDs in Select DX:
What traditional AED can be used in all types of seizures? What newer AED can be used in all seizures?
Traditional AEDs: Valproic acid
Newer AEDs: Lamotrigine
Nsg Implications that apply to all AEDS
Know type of seizure
Educate pts to take med as rx’d
Teach pt/family to maintain seizure frequency chart, indicating date, time, nature of event
Advise pts to avoid potentially hazardous activities until seizure control achieved & to carry some form of ID b/c seizures may reoccur even after they’re under control
Be aware of ones that cause fetal harm/caution in breast-feeding
Nsg Implications that apply to all AEDS:
ADRs:
Most AEDs cause CNS depression – warn pts against etoh & CNS depressant use
Abrupt discontinuation –> SE (must be over 6wks –> several months)
Take lowest effective dose during pregnancy & to reduce risk of neural tube deficits; advise women to take folic acid supplements before & throughout pregnancy
Educate pt/family about sx that might precede suicide: increased anxiety, agitation, mania, hostility
D/c use if severe skin reactions develop (more common in genetic mutation, which mostly occurs in Asian descent)
Classification of Antiepileptic Drugs:
What are the two major categories?
Traditional AEDs
Newer AEDs
Notable AEDs: Phenytoin(Dilantin)
What is the mode of action?
MOA: inhibition/blockade of Na+ channels so action potentials suppressed
Notable AEDs: Phenytoin(Dilantin)
What is it used for?
Use: Partial & tonic-clonic seizures
IV for generalized convulsive SE
Notable AEDs: Phenytoin(Dilantin)
What is the difficulty with this drug?
Absorption varies, hard to establish effective dose, standardize, with meals
Difficult to maintain plasma levels within the therapeutic range
Notable AEDs: Phenytoin(Dilantin)
How is this drug taken? What happens?
Oral – chewable, ext Release
IV – hypotension (give slow), tissue damage if infiltrates
Notable AEDs: Phenytoin(Dilantin)
How is this drug taken fast or slow? What happens?
Small increments in dosage produce sharp increases in plasma drug levels. HD = prolonged ½ life
Difficult to maintain plasma levels within the therapeutic range
Notable AEDs: Phenytoin(Dilantin)
How is therapeutic index?
Narrow TI ~ CNS toxicity when above therapeutic levels, otherwise CNS effects mild
Notable AEDs: Phenytoin(Dilantin)
Narrow TI ~ CNS toxicity when above therapeutic levels, otherwise CNS effects mild= how is this evident?
Nystagmus, sedation, ataxia, diplopia, cognitive impairment
Notable AEDs: Phenytoin(Dilantin)
Drug Interactions (there are many – that ↑&↓ levels)
CYP-450 pathway inducer
Can decrease effects of OCs, warfarin, GCs
Etoh – may increase/decrease serum levels whether taken acutely/chronically
Notable AEDs: Phenytoin(Dilantin)
ADRs?
Gingival hyperplasia
Dermatologic Reactions
CV effects:
Teratogenic
Notable AEDs: Phenytoin(Dilantin)
ADRs: Gingival hyperplasia
What should be done to avoid?
Oral hygiene & supplement w/folic acid
Notable AEDs: Phenytoin(Dilantin)
ADRs: Dermatologic Reactions
Measles-like rash, SJS or toxic epidermal necrolysis
If have genetic variant HLA-B* (Asian descent)
Notify prescriber
Notable AEDs: Phenytoin(Dilantin)
ADRs: CV effects: Because of effects, how should meds be given?
Hypotension & cardiac dysrhythmias when adm by IV injection
Administer slowly
Notable AEDs: Phenytoin(Dilantin)
ADRs: Teratogenic- WHat should be done?
Only use if safer ALTs ineffective
Notable AEDs: Carbamazepine (Tegretol)
Mode of action?
delayed recovery of Na+ channels from inactive state
Suppresses high-frequency neuronal discharge in and around seizure foci
Notable AEDs: Carbamazepine (Tegretol)
PO
Take IR & chewable with food
ER Capsules may be adm whole with food, opened & sprinkled on food, but contents shouldn’t be chewed or crushed
Shake suspensions well
Notable AEDs: Carbamazepine (Tegretol)
What are the uses for this drug?
Partial & tonic-clonic seizures
Notable AEDs: Carbamazepine (Tegretol)
What are ADRs?
CNS effects (nystagmus, blurry vision, diplopia, ataxia))
Derm
SJS & TEN, photosensitivity, measles-like rash
If have genetic variant HLA-B* (Asian descent)
Hematological
Hyponatremia/hypo-osmolality
Hepatic metabolism & inducer of enzymes
Teratogenic
Notable AEDs: Carbamazepine (Tegretol)
What are Hematological effects?
Bone marrow suppression
Leukopenia, anemia, thrombocytopenia
CBC @ baseline & periodically
Report fever, sore throat, pallor, weakness, infection, bruising, petechiae
D/C if WBC < 3000/mm3
Notable AEDs: Carbamazepine (Tegretol)
Hyponatremia/hypo-osmolality: Why does this occur?
ADH secreted
Water retention
Periodic monitoring of serum Na+ recommended
Monitor I&O
Notable AEDs: Carbamazepine (Tegretol)
Hepatic metabolism & inducer of enzymes include? and what do they do?
↑ dose for warfarin & Oral Contraceptives
⍉ GFJ – may ↑ levels
Notable AEDs: Valproic Acid VPA (Depakote):
How can it be taken?
PO ~ ER tabs with meals to avoid GI upset
Can be sprinkled on soft food, but not crushed
Notable AEDs: Valproic Acid VPA (Depakote)
MOA: What does it block / suppress?
Blocks Na+ channels
Suppresses Ca+ influx thru channels
Notable AEDs: Valproic Acid VPA (Depakote)
MOA: What does it augment?
May augment the inhibitory influence of GABA
Notable AEDs: Valproic Acid VPA (Depakote):
What are its uses?
Partial & generalized, very broad-spectrum
Notable AEDs: Valproic Acid VPA (Depakote):
What is the dangerous thing with this drug?
Highly Teratogenic, pregnancy is contraindicated
Notable AEDs: Valproic Acid VPA (Depakote):
What should be done with pregnancy?
Advise woman use effective birth control
Take 5mg of folic acid to reduce risk of neural tube deficits if pregnancy occurs
Notable AEDs: Valproic Acid VPA (Depakote):
ADEs
Liver injury (rare)
Fatal pancreatitis
Hyperammonemia
Notable AEDs: Valproic Acid VPA (Depakote):
ADEs: Liver injury (rare)
High risk – younger than 2 yrs old receiving multidrug tx
Baseline & periodic LFTs, bleeding time
Report reduced appetite, malaise, nausea, abdominal pain, jaundice
Notable AEDs: Valproic Acid VPA (Depakote):
ADEs: Fatal pancreatitis?
Report abdominal pain, distension, nausea, vomiting, anorexia, fever, malaise
D/C stat if (+)
Idiosyncratic reaction
? Reduces enzymes that remove free radical –> tissue damage
Notable AEDs: Phenobarbital
What is the mode of action?
Potentiating effects of GABA
Binds to GABA receptors
Anticonvulsant barbiturate
Notable AEDs: Phenobarbital
What are uses for this drug?
Partial seizures (simple & complex)
Tonic-clonic seizures
Notable AEDs: Phenobarbital
What are Adverse Drugs Events?
CNS depression (lethargy, depression, learning impairment
Peds – paradoxical effect
Notable AEDs: Phenobarbital
How is this drug administered?
PO
IV
Reserved for convulsive SE
Notable AEDs: Phenobarbital
How is this drug with Pregnancy?
Risky in pregnancy
major fetal malformations
Notable AEDs: Phenobarbital
What can this drug do differently from other barbiturates?
In contrast to other barbiturates, phenobarbital can suppress seizures without causing generalized CNS depression.
Notable AEDs: Phenobarbital
How are effects?
Effects are modest.
Can reduce seizures without causing sedation
Newer AEDS: What are benefits of them?
Better tolerated
Less fetal risk
Some are used for monotherapy, others as adjuncts
Newer AEDS: Lamotrigine (Lamictal)
What is the mode of action?
Blocks Na & Ca channels
Both actions ↓ glutamate release, an excitatory NT
Newer AEDS: Lamotrigine (Lamictal)
MOA: When Na and Ca channels are blocked, what does it cause?
Both actions ↓ glutamate release, an excitatory NT
Newer AEDS: Lamotrigine (Lamictal)
What is the use?
Partial & generalized
Adjunct tx in peds & adults
Monotherapy in partial > 16y converting from another AED
Newer AEDS: Lamotrigine (Lamictal)
What is the drug interactions?
CYP-450 inducers/inhibitors
Other AEDs, estrogens & progesterone can lower lamotrigine levels (concern with OCs)
Newer AEDS: Lamotrigine (Lamictal):
ADRs and how is pregnancy?
Dizziness, diplopia, blurred vision, nausea, vomiting, ataxia and headache
Life-threatening severe skin reactions
-Concurrent use of valproic acid increase risk
Risk for suicide
Safer in pregnancy but small risk of cleft palate/lip
Newer AEDS: Gabapentin (Neurontin)
What is the mode of action?
MOA: GABA analog, enhances GABA release, increases GABA-mediated inhibition of neuronal firing by pushing up GABA
Newer AEDS: Gabapentin (Neurontin)
Use:
Use: adjunct tx of partial
Newer AEDS: Gabapentin (Neurontin)
Off-label use:
Neuropathic pain, prophylaxis of migraine, treatment of fibromyalgia.
Newer AEDS: Gabapentin (Neurontin)
For seizures, how much is given?
For seizures, higher dose is given
Newer AEDS: Gabapentin (Neurontin)
What does it do to liver metabolizing enzymes?
Doesn’t inhibit/induce liver metabolizing enzymes
Newer AEDS: Gabapentin (Neurontin)
How is it eliminated?
Eliminated mostly unchanged in urine
Gabapentin (Neurontin):
ADRs:
Very well tolerated
Most common side effects: Somnolence, dizziness, ataxia, fatigue, nystagmus, increased appetite, irritability and peripheral edema
Monitor weight & behavioral changes
Unique agent that is chemically and pharmacologically different from all other AEDs.
Levetiracetam (Keppra)
Levetiracetam (Keppra):
What does it inhibit? What does it NOT do?
Inhibits excessive firing
Does not bind to receptors, GABA, or other NTs
Levetiracetam (Keppra):
What are uses for it?
Use: adjunct treatment for general, monotherapy for partial, preventative
Levetiracetam (Keppra)
How is it tolerated? Pregnancy and otherwise?
Better tolerated, less risk to fetus
Levetiracetam (Keppra):
How does it interact with other drugs?
Less interactions w/other drugs as opposed to traditional ones
Started as adjuncts
Levetiracetam (Keppra)
Mechanism of action: Unknown, binds to synaptic vesicle protein (SV2A), which is involved in the regulation of neurotransmitter release.
This helps stabilize neuronal activity and prevents seizure propagation.
Levetiracetam (Keppra):
Adverse effects?
Adverse effects: Mild to moderate
Most common are drowsiness & lack of strength, weakness
Levetiracetam (Keppra):
Drug interaction:
Drug interaction: Does not interact with other AEDs
Levetiracetam (Keppra):
How is it given?
Can be given PO, IV
Adm with or w/o meals
Swallow whole
Infuse over 15 min
Management of Generalized Convulsive Status Epilepticus SE
When should treatment be started? Why?
TX STAT ~ Give 5 min of onset
TX resistance with time progression
Management of Generalized Convulsive Status Epilepticus SE
What occurs with the first line management?
Strong binding to the GABA-benzodiazepine receptor complex
Binding enhances the affinity for GABA (gamma-aminobutyric acid), a NT that plays a crucial role in inhibiting nerve impulses within the brain.
Calming Effect: By enhancing GABA’s inhibitory action, lorazepam helps reduce excessive neuronal activity, calming the brain.
Management of Generalized Convulsive Status Epilepticus SE
What is first line management?
1st line management: Benzodiazepam (lorazepam/Ativan), diazepam (valium)
Management of Generalized Convulsive Status Epilepticus SE:
Goals of treatment
Establish IV line ~ blood analysis: glucose, electrolyte, drug levels
Maintain ventilation
Correct hypoglycemia
Terminate seizures ~ initial BDZ -»drowsiness, dizziness, confusion, resp depression
Initiate or continue long-term suppression ~ phenytoin or fosphenytoin, levetiracetam
