anti- convulsants Flashcards
(152 cards)
1
Q
What is a seizure?
A
a single episode of abnormal electrical discharge from cortical neurons that results in an abrupt & temporary altered state
2
Q
What is epilepsy?
A
a group od syndromes characterized by unprovoked, recurrent seizures
3
Q
What is status epillepticus?
A
continuous seizure activity for more than 5 minutes or 2 or more sequential seizures that occur without full recovery of consciousness between attacks
4
Q
What are the common causes of seizures?
A
trauma
ETOH withdrawal
illicit drug use
brain tumor
congenital malformations
stroke
metabolic disorders
- uremia, electrolyte imbalance
alzheimers
neurodegenerative disease
idiopathic
5
Q
What can trigger a seizure?
A
- flashing lights
- stress
- certain drugs
- metabolic changes
6
Q
What are the 5 common causes of epilepsy?
A
genetic causes
head trauma
medical disorders
prenatal injury
developmental disorders
7
Q
What should we know about genetic causes of epilepsy
A
> 30 mutated genes have been found in families with epilepsy
- may occur in genes coding for different things (ex. ion channels, neuronal receptors, transcription factors)
- many pediatric epilepsies are associated w/ randon gene mutation for the first time (de novo)
- about half of seizure disorders, no genetic or structural abnormality is present
8
Q
What medical disorders can cause epilepsy?
A
- dementia
- meningitis
- encephalitis
9
Q
What developmental disorders can cause epilepsy?
A
- autism
- down syndrome
10
Q
how do seizures work?
A
- messages from the body are carried by the neurons (nerve cells) of the brain through discharges of electrochemical energy
- these impulses occur in bursts
- during periods of unwanted discharges, parts of the body may act erratically
11
Q
What is needed for an actual seizure to occur?
A
- excitable neurons
- increased excitatory glutaminergic activity
- reduction in activity of normal inhibitory GABa projection
12
Q
Who can have a seizure?
A
anyone!
13
Q
what are the two classifications of seizures?
A
focal or partial
generalized
14
Q
what are the two kinds of focal or partial seizures?
A
simple partial
complex partial
15
Q
What are the types of generalized seizures?
A
absence (petit mal)
tonic-clonic (grand mal)
atonic/akinetic (drop attacks)
status epilepticus
16
Q
Where in the brain are focal seizures?
A
start & remain in 1 hemisphere
17
Q
In focal seizures there are _____- ___________ burst of action potentials & ____________________
A
high- frequency; hypersynchronization (large number of neurons dire action potentials together)
18
Q
what do focal seizure affect?
A
sensory & motor function
autonomic sx
automatism
19
Q
What are the autonomic sx of focal seizures?
A
due to stimulation of ANS
- pallor
- sweating
- pupillary dilation
- epigastric sensation
20
Q
What is automatism?
A
coordinated involuntary movements occuring during state of impaired consciousness either during or after seizure. Pt is unaware, often associated with temporal seizures
21
Q
Is pt aware or unaware in focal seizures?
A
awareness can be maintained or lost
22
Q
do pts have aura with focal seizures?
A
some may experience a warming sensation before seizure
23
Q
What are characteristics of focal seizures when pt retains awareness?
A
- no impairment of consciousness
- similar to partial seizures
- may have movement of body parts
- may experience an aura
24
Q
What are characteristics of a focal seizure when awareness is altered?
A
- impairment of consciousness
- spreads to both hemispheres
25
What are characteristics of partial seizures?
- begins in part of one hemisphere (typically in the temporal lobe)
- may be simple or complex
26
In what part of the brain does a generalized seizure occur?
- start in 1 hemisphere & spreads w/ involvement of both hemisphere
- affects both hemispheres of the brain
27
do generalized seizures have motor sx?
may have motor and/or nonmotor sx
28
is consciousness maintained or impaired in generalized seizures?
impairment of consciousness
29
What occurs in a tonic-clonic seizure (grand mal)?
begin with rigid violent contractions (tonic) followed by repetitive clonic activity of all extremities; body stiffness & relaxation
30
What are tonic seizures characterized by?
- muscle stiffness
- dilation of pupils
- altered respirations
- usually less than a minute
31
what are absence seizures characterized by?
short episodes of staring & loss of consciousness
- last around 10 seconds
32
What are myoclonic seizures characterized by?
- bilateral jerking of muscles
- no loss of consciousness
33
What are atonic seizures characterized by?
- sudden loss of muscle tone causing a person to collapse or drop to the ground
34
is status epilepticus an emergency?
yes; a neurological emergency
35
What does status epilepticus need?
requires immediate intervention because of the extreme energy expenditure & potential lack of oxygen during prolonged seizures
36
how is a seizure dx?
H & P
neurological exam
diagnostic procedures
37
What diagnostic procedures are used to dx a seizure?
- chemistries/ blood work for toxins to check for drug-related causes
- toxicology screen
- CT/MRI to r/o structural causes like tumors
- EEG to measure brain rhythms & to capture abnormal brain activity during a seizure
38
What are the three phase of a seizure?
pre-ictal
ictal
post-ictal
39
What is the pre-ictal phase of a seizure?
when seizure may be started by a trigger and/or preceded by an aura
40
What happens during the ictal phase of a seizure?
- actual seizure
- increases in metabolic demand
41
What happens in the post-ictal phase?
- has decreased responsiveness
- feels fatigue
42
What is important to do during the post-ictal phase?
keep pt safe & monitor their recovery
43
What are anticonvulsants also known as?
antiepileptic drugs (AED)
44
What are indications for anticonvulsants?
- used for long term management of chronic epilespsy
- management of seizures not caused by epilepsy
- off-label uses
45
What are the off-label uses for anticonvulsants?
- anxiety
- bipolar disorder
- chronic pain
- migraines
46
What is selection of medication for tx based on?
classification of seizures & epilepsy
- broad spectrum
- narrow-spectrum
47
What are broad spectrum anticonvulsants used for?
effective for tx of focal & generalized seizure
48
What are narrow spectrum anticonvulsants used for?
used primarily for focal- onset seizures (including focal which evolve to b/l convulsive seizures)
49
What are the factors that are evaluated when selecting an anticonvulsant medication?
- efficacy
- tolerability
- presence of comorbidites
- pharmacokinetic profile
- potential drug-drug interactions
- ease of use
- cost
-age
- gender
50
anticonvulsants are to __________ seizures; not ____
control; cure
51
What is the anticonvulsant prescribed based on?
type of seizure
52
What do many anticonvulsants require?
blood monitoring
53
What patient education should be given related to anticonvulsants?
- take as precribed
- never stop taking on own
- side effect management
54
What class is phenytoin a part of?
sodium channel blocker
55
How does phenytoin work?
- works to stabilize the neurons from becoming too excited
- stops the spread of seizure activity in the motor cortex
56
phenytoin is _______ (90%) protein- bound meaning it has a higher risk for ______ _____________
highly; drug interactions
57
What are indications for Phenytoin?
tonic- clonic seizures
status epilepticus
prophylaxis for surgery
58
What is the therapeutic range for phenytoin?
10-20mcg/ml; very narrow therapeutic range
59
What should you monitor in pts taking phenytoin?
peak & troughs
60
What are the routes of administration for phenytoin?
PO, IM, & IV
61
What are precautions for giving IV phenytoin?
- infuse over 30-60 minutes
- can be very irritating to veins
62
What should you do for those taking phenytoin & on tube feeds?
need to stop tube feed for 2 hrs before & after giving med
63
What are the side effects of phenytoin?
neurologic
- drowsiness
- ataxia
- irritability
- visual problems
- peripheral neuropathy
- N/V
- headache
cardiovascular
- hypotension
- arrhythmias
skin
- rash
- steven- johnsons syndrome
other
- suicidal thoughts
- gingival hyperplasia (gum overgrowth)
64
How does phenobarbital work?
inactivates fast sodium channels leading to enhanced GABA effects & decreased glutamate release
65
What class is phenobarbital in?
barbiturates
66
What is the half-life of phenobarbital?
very long half-life
67
What are the side effects of phenobarbital?
- sedation
- respiratory depression
- diplopia (double vision)
- cognitive skill impairment
- hypotension
- hyperactivity & inattention in children
68
What can phenobarbital cause?
physical dependence
69
What is carbamazepine's mechanism of action similar to?
phenytoin
70
What class does carbamazepine belong to?
sodium channel blockers
71
What types of seizures is carbamazepine used for?
- used for several different types of seizures
- drig of choice for partial & generalized tonic-clonic seizures
- avoid in absence or myoclonic seizures as it may worsen them
72
Carbamazepine inhibits the spread of __________ activity
seizures
73
Where should carbamazepine be kept?
needs to be kept in a dry location (not a bathroom)
74
for what disorders is carbamazepine used off-label?
- trigeminal neuralgia
- bipolar disorder
75
What does carbamazepine interact with?
oral contraceptives; reducing their effectiveness
76
What labs should be performed when taking carbamazepine?
CBC (esp. WBC)
drug levels
sodium
CBC
LFTs
BUN/Cr (esp in those with renal impairment)
77
What is the therapuetic level of carbamazepine?
4-12 mcg/ml
78
What are side effects of carbamazepine?
- rash
- steven johnson syndrome
- increased SI
- headache
- diplopia
- ataxia
- drowsiness
- sedation
- N/V
- hyponatremia
- decreased blood counts (neutropenia & thrombocytopenia)
79
should carbamazepine be taken with or without food?
take with food
80
What should you never do when taking carbamazepine?
stop abruptly
81
oxycarbazepine has the same efficacy as _________________, but is better tolerated
carbamazepine
82
What does oxycarbazepine work as?
a sodium channel blocker
83
When is oxycarazepine used?
used as adjunctive therapy or monotherapy for partial seizures in children & adults
84
With what seizures should oxycarbazepine not be used?
absence & myoclonic because it may worsen them
85
oxycarbazepine decreases efficacy of _____ _______________
oral contraceptives
86
What can oxycarbazepine increase the risk of?
suicidal ideations
87
How does valproic acid/ valproate work?
inactivation of fast sodium channels; GABA enhancer
88
What are the indications for valproic acid?
- absence seizures
- myoclonic seizures
- tonic-clonic seizures
- partial seizures
- neonatal seizures
89
When is valproic acid used off-label?
used to contol sx of acute mania in bipolar disorder
90
What can valproic acid be given with?
phenytoin
91
What are the side effects of valproic acid?
- N/V
- sedation/ dizziness
- pancreatitis
- increased ammonia levels
- thrombocytopenia (monitor CBC)
- suicidal thoughts
- liver toxicity
92
What should you monitor with a pt on valproic acid?
monitor CBC
monitor LFTs
check therapeutic levels
93
What is the therapeutic level of valproic acid?
50-100 mcg/ml; narrow therapeutic range
94
Should valproic acid be taken with or without food?
taken with food
95
How should IV valproic acid be given?
- must be diluted with at least 50ml NSS or D5W
- give over an hour (no more than 20mg/min)
96
What should you avoid with valproic acid?
avoid sudden withdrawal
97
How does gabapentin work?
thought to act on calcium channels to decrease glutamate & increase GABA in the brain
98
What are indications for gabapentin?
partial seizures
new onset epilepsy
99
with what seizures should gabapentin not be given?
myoclonic seizures; may worsen them
100
What are the off- label uses for gabapentin?
- chronic neuropathic pain
- anxiety
- hot flashes/night sweats
- headaches
- hiccups
- alcohol withdrawal
101
What are the side effects of gabapentin?
- fatigue (often given at night)
- mental cloudiness
- leukopenia
- edema
- weight gain
- emotional lability
- tremors
- GI side effects
- suicidal thoughts
102
What should you do for renal patients taking gabapentin?
reduce dose in renal patients
103
when should gabapentin be used cautiously?
cautious use in those with an addiction history
104
Do you need to monitor drug levels for gabapentin?
no
105
how should you stop gabapentin?
withdrawal slowly
106
When will gabapentin doses be very high?
doses will be very high for pain control
107
How does lamotrigine (lamictal) work?
works on sodium channels which decreases the release of specific neuro- transmitters (glutamate) calming brain activity
108
What are indications for lamotrigine?
- partial seizures
- children older than 2 for generalized seizures
109
What should lamotrigine not be given with and why?
should not be given with valproic acid
- cause toxic levels
110
What do other AEDs do to lamotrigine?
other AEDs will decrease levels of lamotrigine
111
What can lamotrigine effect the efficacy of?
oral contraceptives
112
What are the side effects of lamotrigine?
- dizziness
- diplopia
- ataxia
- headaches
- N/V
- weight gain
- neutropenia (rare)
113
What is the black box warning for lamotrigine?
- rashes
- stevens johnson
114
How should lamotrigine be given and what does this avoid?
start at very low dose & titrate up slowly to avoid rash
115
What should be monitored when taking lamotrigine?
Need to monitor drug levels but window is not as narrow as others
116
What is levetiracetam (keppra) indicated for?
- partial seizures
- generalized seizures
117
What are side effects of levetiracetam?
- irritability
- depression
- fatigue
- suicide ideations
hypotension
- decreased blood counts
- hyponatremia
- steven-johnsons
118
Are there any interactions with levetiracetam (keppra)?
no known drug interactions
119
What should you avoid when taking levetiracetam (keppra)?
avoid stopping abruptly
120
What should you monitor for pts on levetiracetam (keppra)?
- CBC
- blood pressure
- rash
121
What are the indications for topiramate (topamax)?
- tonic-clonic
- focal seizures
122
What are the off label uses for topiramate (topamax)?
- migraines
- mood stabilizers
123
What are the side effects of topiramate (topamax)?
- fatigue
- weight loss
- sedation
- cognitive dysfunction
124
What can other anticonvulsants do to topamax?
other anticonvulsants may decrease levels ( usually by itself)
125
What is ethosuzimide (zarontin) indicated for?
ABSENCE SEIZURES ONLY
126
Should you take ethosuximide (zarontin) with or without food?
Take with food
127
What drugs interact with ethosuximide (zarontin)?
- phenytoin
- valproic acid
128
What should you monitor when a pt is on ethosuximide (zarontin)?
- CBC
- LFTs
- renal function
129
What are the side effects of ethosuximide (zarontin)?
- diarrhea
- dizziness
- headache
- N/V
- rash
130
What kind of medication is zonisamide (zonegran)?
- sulfa med (avoid w/ allergy)
- add on therapy
131
What can zonisamide (zonegran) cause?
steven johnsons
132
What can zonegran decrease & what do we need to check because of that?
can decrease sweating so watch body temp
133
How must zonegran be taken?
by swallowing capsule whole
134
What class of medications is lorazepam (ativan) in?
is a benzo (increases GABA)
135
What is lorazepam the drug of choice for?
status epilepticus
136
How is lorazepam (ativan) given for seizures?
Given IVP - want to stop seizure activity
137
What can lorazepam also be used for?
to treat anxiety & panic attacks
138
What can lorazepam cause?
- sedation
- resp depression
139
What can prolonged use of lorazepam cause?
can be addictive & drug of abuse; controlled substance IV
140
What is the antidote for benzos?
flumazenil
141
What are the other benzos?
- diazepam
- clonazepam
142
What drugs are used for partial (simple & complex) seizures?
- cabamazepine
- phenytoin
- lamotrigine
- gabapentin
- valproate
- topiramate
- oxycarbazepine
143
What drugs are used for generalized (tonic-clonic) seizures?
- carbamazepine
- valproate
- phentoin
- phenobarbital
- levetiractam
- oxcarbazepine
- topiramate
- zonisamide
144
What drugs are used for generalized (absence) seizures?
- ethosuximide
- valproate
- lamotrigine
145
What drugs are used for status epilepticus?
- daizepam/lorazepam
- phenytoin
- phenobarbital
146
What should you know when a patient is on an anticonvulsant?
know why your patient is on the medication
147
What should you assess for when a pt is on anticonvulsants?
- medication efficacy
- SI (esp when first started/ mood changes)
- liver/renal function
- bone marrow (esp plt & WBC)
- rashes ( want to prevent steven johnsons)
- fall risk (due to sedation/drowsiness)
148
What should you educate pts on when taking anticonvulsants?
- NEVER STOP ABRUPTLY
- used & side effects
149
What should you encourage pts taking anticonvusants to wear?
a medical alert bracelet
150
What should you help pts recently dx with seizures do?
help pt adapt to dx & being on chronic meds
151
When can anticonvulsants be discontinued?
may be done if pt meets the following criteria:
- seizure onset was between 2 & 35
- normal EKG
- seizure free for 2 to 5 years
152
How should anticonvulsant therapy be discontinued?
- discontinue therapy over 3-6 months or more
- closely monitor for the first year
