Anti-seizure Medication Flashcards
What is epilepsy?
disturbances of mental functions or movements of the body that is due to excessive discharge of signals from brain cells
Epileptic seizures are an imbalance of what?
GABA and Glutamate neurotransmission
What are some causes of epilepsy?
idiopathic epilepsy
trauma
tumor
developmental abnormality
stroke
What is a partial seizure?
a seizure that occurs on one side of the brain
What is a generalized tonic-clonic seizure?
abnormal on both sides of the brain
What does a generalized absence seizure look like?
- shown as a 3-Hertz spike wave on both sides of the brain
Absence seizures occur so quickly that ______?
another seizure occurs before the patient is even conscious which could lead to hypoxia which then leads to brain damage
What are the 4 options of treatment for Epilepsy?
- Benzodiazepine
- Phenytoin/fosphenytoin/valproic acid/levetiracetam
- Phenobarbital
- Propofol
What is the strongest treatment for epilepsy?
Propofol (general anesthetic)
What is the most common type of seizure?
convulsion seizures
What are the different types of seizures? (4)
- Convulsive Seizures
- Absence
- Myoclonic
- Atonic
Which two seizures do you lose consciousness?
Convulsive Seizures
Absence
Which two seizures do you POSSIBLY lose consciousness?
Myoclonic and Atonic
What are automatisms?
repetitive gestures
What occurs during simple partial seizures?
uncontrolled muscle movements
automatisms
no loss of consciousness
Where does simple partial seizures originate?
1 hemisphere
What are the three parts of a seizure?
- Aura
- Ictus
- Postictus
What is an aura?
sensation or mood that will help identify location of seizure
What is an ictus?
the seizure itself; “what it looks like”
What is a postictus?
the period after the seizure
Auras do not occur in what types of seizures?
absence and myoclonic seizures
Postictus do not occur in what types of seizures?
absence seizures
How do you dose seizure medications?
you begin with one drug then you increase the dose until seizures stop or toxicity occurs, if seizures do not stop add another drug therapy and slowly increase that does as well until the seizures stop or toxicity occurs
Why measure serum levels of anti-seizures medications? (3)
- Help prevent toxicity
- Insure adequate dosing
- Increase patient compliance
What are the major mechanisms of action of for anti-seizure drugs? (3)
- decreases sodium and calcium influx
- increase GABA neurotransmission
- decrease glutamate/asparatate neurotransmission
What are the general side effects of anti-seizures drugs?
CNS effects: fatigue, dizziness, ataxia, blurry vision, headaches
GI upset
alterations in blood counts
potential to cause Stevens Johnson Syndrome
What are the comorbidities for anti-seizure drugs?
anxiety, depression,
How does Stevens Johnson Syndrome start?
a rash after using a seizure medication
What is the mechanism of action for Phenytoin (Dilantin)?
Na channel blocker; has the same mechanism as anesthetics
What is the drug that neurologists would not recommend?
Phenytoin (Dilantin)
What type of seizure is Phenytoin not used to treat?
absence and atonic epilepsy because it can exacerbate these issues
Why does it take phenytoin take a long time to get the brain?
because it has high protein binding
What are the two ways that Phenytoin can be administered?
oral or IV
What is a side effect of phenytoin that occurs in children?
Gingival Hyperplasia
What is Gingival Hyperplasia?
abnormal amount of collagen
What is a side effect of phenytoin?
Hirsutism
What is Hirsutism?
abnormal amount of facial hair
What does Phenytoin induce?
CYP3A4, CYP2C, and UGT
When taking Phenytoin patients should be treated with _______ to prevent _____ ?
- vitamin K supplements
- bleeding
What type of drug is Fosphenytoin?
prodrug
How is Fosphenytoin administered?
IM
What is the difference between phenytoin and fosphenytoin (Cerebyx)?
less hypotension risk
What is the enzyme that converts fosphenytoin to phenytoin?
phosphatases
What is the mechanism of action for Carbamazepine (Tegretol)?
blockage of Na channels
What are the uses of Carbamazepine (Tegretol)? (3)
generalized and partial seizures
trigeminal neuralgia (facial pain)
bipolar disorder
What does Carbamazepine induce?
CYP1A2, CYP2C, CYP3A, UGT
True or False: Carbamazepine do not induce their own metabolism with the rate of metabolism increasing in the first 4-6 weeks of therapy
False: they do induce their own metabolism
What is carbamazepine (Tegretol) metabolized to?
10,11 - epoxide which is pharmacologically active
What are the side effects of Carbamazepine (Tegretol)?
weight gain
Steven-Johnson syndrom
Hyponatremia
Liver toxicity
With what types of seizures are carbamazepines contraindicated?
in absence seizures
What is the mechanism of action of Ethosuximide?
calcium channel blocker
What is the indication of Ethosuximide?
absence seizures ONLY
What are the side effects of Ethosuximide?
GI irritation
blood dyscrasias
What is the mechanism of action for Phenobarbital (Luminal)?
binds to the GABA receptor and then enhances GABA mediated chloride flux and prolongs opening of GABA channel
What are the indications associated with Phenobarbital (Luminal)?
status epilepticus
Can phenobarbital be used for veterinary medications?
No
In what type of seizures is Phenobarbital (Luminal) contraindicated?
in absence seizures because of the cognitive effect
What are the 2nd line uses for phenobarbital (luminal)?
generalized tonic-clonic epilepsy
partial seizures
What does phenobarbital (luminal) induce?
induction of CYP450 enzymes
What are the side effects of phenobarbital (luminal)?
nystagmus
highly sedating
ataxia, cognitive impairment
What is the mechanism of action of Primidone (Mysoline)?
facilitates GABA, Block Na channels
What are the metabolites of Primidone (Mysoline)?
Phenobarbital and PEMA
What are the indications of Primidone (Mysoline)?
partial seizure and tonic-clonic
What are the side effects of Primidone (Mysoline)?
nystagmus
highly sedating
ataxia, cognitive impairment
What is the mechanism of action for Divalproex (Depakote)?
elevates brain levels of GABA by inhibition of degradation
potentiates inhibitory effects of GABA
Blockage of Na and Ca channels
What are the side effects of Divalproex (Depakote)?
alopecia and weight gain
What are the different formulations of Divalproex (Depakote)?
Valproic acid
Divalproex sodium
What are the indications of Divalproex (Depakote)?
absence seizures refractory to ethosuximide
generalized and partial seizures
bipolar disorder
prophylaxis of migrains
(broad spectrum)
What does Divalproex (Depakote) inhibit?
CYP450, UGT, and Epoxide Hydrolase
What are the drug interactions with Divalproex (Depakote)? (2)
- Displaces phenytoin from plasma proteins
- Inhibits hepatic oxidative metabolism of carbamazepine, phenobarbital, and phenytoin
What is the mechanism of action of Lorazepam (Ativan)?
enhances GABA activity by binding allosterically to the GABA receptor
What are the uses of Lorazepam (Ativan)?
IV agent in status epilepticus
What are the side effects of Lorazepam (Ativan)?
sedation
anteroprade amnesia
ataxia
withdrawal seizures following abrupt cessation
What are the benzodiazepines that are for chronic treatment of seizures?
- Clorazepate (Tranxene)
- Clonzepam (Klonopin)
What is Clorazepate metabolized to?
Diazepam
What is the type of seizure that Clonazepam treats?
absence seizure
What does Clobazam treat?
adjunctive for Lennox-Gastaut in patients 2 years of age or older
What are the BDZ Nasal Sprays?
Midazolam (Nayzilam) and diazepam (Valtoco)
What is Diastat Acudial?
rectal administration
When is Diastat Acudial used?
optional treatment for long lasting seizure
What are the advantages of Second Generation Antiepileptics?
- fewer side effects
- little or no need for serum monitoring
- fewer drug interactions
What is the mechanism of action for Gabapentin (Neurontin)?
Analong of GABA and inhibits Ca channels
*may increase the release of GABA from neurons
What are the uses of Gabapentin (Neurontin)?
- partial seizure
- postherpetic neuralgia
- migraine, chronic pain, bipolar disorder
- alcohol and opiate withdrawal
What patient population is Gabapentin (neurontin) best for?
the elderly
What is a side effect of Gabapentin?
somnolence, weight gain
When is the best time to take Gabapentin?
in the evening because it causes sedation
What is the mechanism of action Pregabalin (Lyrica)?
binds calcium channels and decreases glutatmate activity
What are the side effects of Pregabalin (Lyrica)?
Somnolence and weight gain
Is Pregabalin (Lyrica) metabolized in the liver?
no
What are the indications for Pregabalin (Lyrica)?
- adjunctive therapy for partial onset seizures
- diabetic neuropathic pain
- postherpetic neuralgia
- fibromyalgia
What is the mechanism of action for lamotrigine (lamictal)?
inhibits voltage-sensitive Na and Ca channels and inhibits glutamate/aspartate release
What are the uses of lamotrigine (Lamictal)?
broad spectrum: treatment of partial and generalized seizures and absence seizures and bipolar disorder
What are the side effects of Lamotrigine (Lamictal)?
skin rash, higher risk of Stevens-Johnson and higher risk of children
What age group should not use Lamotrigine (Lamictal)?
< 16 years old
What is the metabolism of Lamotrigine (Lamictal) decreased by?
CYP inhibitors (valproic acid)
What is the metabolism of Lamotrigine (Lamictal) increased by?
CYP inducer (phenytoin and CBZ)
What is the mechanism of action of Topiramate (Topamax)?
inhibits voltage-dependent Na channels
potentiates GABA neurotransmission
blocks glutamate neurotransmission
What are the indications of Topiramate (Topamax)?
partial and generalized seizures
migraine prophylaxis
alcoholsim
What are the side effects of Topiramate (Topamax)?
Nephrolithiasis (kidney stones)
Metabolic acidosis
Weight loss
Oligohydrosis (reduced perspriation)
What is the mechanism of action of Levetiracetam (Keppra)?
unknown
What is the use of Keppra?
partial and generalized seizures
is Keppra metabolized by CYP450?
no; therefore, it is good for patients with hepatic disease
What is a side effect of Keppra?
mood changes
What are the uses of Keppra?
antiseizures, bipolar disorder, and migraine prophylaxis
Oxcabazepine does not induce its own metabolism
true
What is the MOA of Oxcabazepine (Trileptal)?
blocks voltage dependent Na channels
What patient population has an increased risk oof SJA?
asian populations
What is the indication of Oxcabazepine?
partial seizure
What type of drug is Oxcabazepine?
prodrug
What is the active metabolite of Oxcabazepine?
eslicarbazepine
What is the drug that is used with patients that haven’t responded well to other medications?
Vigabatrin (Sabril)
What is the mechanism of action of Vigabatrin (Sabril)?
inhibition of GABA transaminase induces CYP2C9
What is the use of Vigabatrin (Sabril)?
reduction of partial seizure (refractory patients)
What is the side effects of Vigabatrin (Sabril)?
drowsiness, dizziness, weight gain, suicide, and permanent vision loss
What is the mechanism of action of Peramapanel (Fycompa)?
AMPA receptor antagonist
What are the adverse effects of Peramapanel (Fycompa)?
psychiatric
aggressive behavior
psychosis
suicidal ideation
How is Permapanel (Fycompa) contraindicated?
patients with preexisting psychiatric illness/psychosis
What is Lennox-Gaustaut Syndrome?
is a multitude of seizures
How do you treat Lennox-Gaustaut Syndrome?
poly-drug approach
What is the mechanism of action of Felbamate (Felbatol)?
blocks activation NMDA receptors
blocks Na and Ca channels
Enhances GABA
What is Felbamate (Felbatol) recommended for?
patients who respond inadequately to alternative treatments and whose epilepsy is very severe
What is the drug that requires consent from a parent?
Felbamate (Felbatol)
What are the side effects of Felbamate (Felbatol)?
- acute liver failure
- aplastic anemia
When do you use Epidiolex?
for treatment resistant seizures
What is the mechanism of action of Epidiolex?
seritonin and glycine receptors
What are non-pharmacological therapy that treats seizures?
- Ketogenic Diet
- Vagus Nerve Stimulation
how do you treat Epilepsy in pregnancy?
- monotherapy
- folic acid supplementation before/during pregnancy
What are the ways that folic acid supplementation helps with baby growth?
- DNA synthesis
- RBC production
- Developmental of brain, spinal cord
- Helps prevent birth defects and low birth weight
What are the 3 drugs to avoid to treat epilepsy in pregnant women?
- Phenytoin
- Carbamazepine
- Phenobarbital
What does phenytoin cause in children?
cleft palate and poor cognition
What does carbamazepine cause in children?
cleft palate
What does phenobarbital cause in children?
cardiac malformations and poor cognition