Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
68 Cards in this Set
- Front
- Back
|
What are the prototype established AEDs?
|
Carbamazepine
Phenytoin Phenobarbital Valporic acid Ethosuximide Some benzos |
|
|
What are the prototype new AEDs?
|
Gabapentin
Topiramate Tiagabine |
|
|
What is a seizure?
|
abnormal excessive neuronal discharge within the gray matter associated with abnormal EEG
|
|
|
What is Epilepsy?
|
1. repeated convulsive or non-convulsive seizures
2. abnormal EEG 3. disturbance in consciousness |
|
|
What is a tonic movement?
|
a sustained contraction
|
|
|
What is a clonic movement?
|
alternating contraction and relaxation in rapid succession
|
|
|
What is myoclonus?
|
Brief contraction of muscle in one or more areas of the body
|
|
|
What type of seizures do not impair consciousness? How long do they last?
|
1. Simple partial seizure, less than a minute in duration
Myoclonic seizure has no loss of consciousness, but still impaired. |
|
|
Where in the brain do the majority of complex partial seizures occur?
|
70-90% in the temporal lobe
|
|
|
What seizure type is characterized by a spike-wave discharge that is regular and symmetrical (3Hz spike and slow wave)?
|
Absense seizure
|
|
|
What is Lennox-Gastaut syndrome?
|
Occurrence of multiple seizure types
|
|
|
How are eclampsia associated seizures treated?
|
Mg, not AEDs
|
|
|
What mechanism maintains a seizure once initiated?
|
reentry of excitatory impulses
|
|
|
What is the role of post-tetanic potentiation in the propagation of seizures?
|
causes progressive enhancement of synaptic transmission during rapid, repeated stimulation. This is a critical factor in seizures.
|
|
|
What are the factors that contribute to the self limiting aspect of seizures?
|
1. elevation of firing threshold
2. prolonged refractory period |
|
|
Why is accurate diagnosis of a type of seizure important?
|
wrong AED can cause seizures
|
|
|
Why should anticonvulsant therapy never be stop abruptly?
|
Can cause status epilepticus and drug withdrawal delirium
|
|
|
What are the general mechanisms for AEDs?
|
1. Block voltage gated Na channels
2. Block voltage gated Ca channels 3. Enhance GABA neurons 4. Alter glutamine neurons |
|
|
What is the mechanism of carbamazepine?
|
1. Blocks high frequency Na channel activation
2. Prevents spread 3. Stabilizes neuronal membranes |
|
|
What drug is used to treat hiccups, trigeminal neuralgia, and diabetic neuropathy?
|
carbamazepine
|
|
|
What is the newer carbamazepine? What's different?
|
Oxcarbazepine, causes less autoinduction of metabolism
|
|
|
Which established AED has a very narrow therapeutic range?
|
Phenytoin
|
|
|
What is Stevens-Johnson syndrome? Which AED can cause it?
|
Exfoliation of the skin
Phenytoin |
|
|
What is fosphenytoin used for?
|
Status epilepticus
|
|
|
What is the drug of choice for febrile convulsive children?
|
Phenobarbital
|
|
|
What is the mechanism of phenobarbital?
|
Increases GABA transmission
Inhibits glutamate |
|
|
What is the mechanism of phenytoin? What other drugs in this class have the same function?
|
Na channel block
carbamazepine valproic acid gabapentin topiramate benzos |
|
|
What is the difference between phenobarbital and other barbiturates used to control AED?
|
selective depressant at motor center and epileptogenic focus without much general sedation.
|
|
|
Which AED can cause hyperactivity and irritability in children?
|
Phenobarbital
|
|
|
What are the contraindications for phenobarbital?
|
allergies
porphyria |
|
|
What are the mechanisms of valproic acid?
|
1. Na block
2. Ca block 3 Increases GABA in the brain by stimulating glutamic acid decarboxylase and inhibiting GABA breakdown, and uptake transporters |
|
|
Why are valproic acid metabolites significant?
|
Hepatotoxic
|
|
|
What is the contraindication of valproic acid?
|
liver dz
|
|
|
What is the drug of choice for absence seizures?
|
Ethosuximide
|
|
|
What is the mechanism of ethosuximide?
|
Ca block: blocks spike wave without inhibiting single impulses.
|
|
|
Which benzos are used to control seizures?
|
Clonazepam
Diazepam |
|
|
What is the mechanism of benzos used to control epilepsy?
|
Enhance GABA-mediated Cl- influx
|
|
|
What are the applications of benzo use as AEDs? Why not chronic use?
|
1. manage refractory pts with breakthrough seizures
2. emergency at home use 3. manage status epilepticus Not chronic due to tolerance |
|
|
What is the mechanism of Gabapentin?
|
Blocks Ca channels on presynaptic neuron to decrease glutamate release
|
|
|
Which AEDs are used as prophylaxis for migraines?
|
Gabapentin
Topiramate Valproic acid |
|
|
What is pregabalin?
|
New AED- 6-8 times more potent than gabapentin, use primarily in neuropathies.
|
|
|
What is the mechanism of topiramate?
|
Block Na
Increase GABA Block glutamate receptor activation |
|
|
What percent of topiramate is excreted uncharged by the kidney?
|
70%
|
|
|
Which AED could cause angle-closure glaucoma and a non-anion gap acidosis?
|
Topiramate
|
|
|
What is the mechanism for tiagabine?
|
selective GABA reuptake inhibitor
|
|
|
Why is the half life of tiagabine affected by phenytoin and other AEDs?
|
AEDs that induce metabolism can increase the breakdown of tiagabine
|
|
|
What is lamotrigine?
|
Newer AED
|
|
|
What drug can prolong the half life of lamotrigine?
|
Valproic acid
|
|
|
What is vigabatrin used to treat?
|
partial seizures
|
|
|
What are the adverse effects of vigabatrin?
|
irreversible visual field defects
|
|
|
Which new AED is thought to bind to SV2A vesicle proteins?
|
Levetiracetam
|
|
|
What is zonisamide used for?
|
partial seizures and intractable pain
|
|
|
Why does felbamate have limited use?
|
causes aplastic anemia
|
|
|
What is the mechanism of felbamate?
|
modulates glycine binding
blocks Na inhibits Ca conductance |
|
|
What is rufinamide use for?
|
as an adjunct in seizures associated with lennox-gastaut syndrome
|
|
|
What is lacosamide used for? What is the mechanism?
|
adjunct for partial seizure therapy, by prolonging the refractory period of Na channels.
|
|
|
What are three important drug-drug interactions in the polytherapy of epilepsy?
|
1. displacement of plasma protein bound drugs
2. metabolic inducers 3. excessive sedation |
|
|
What AEDs are bound to plasma proteins to a high degree?
|
Phenytoin
Valproic acid |
|
|
Which AEDs are strong metabolic induces?
|
Carbamazepine
phenobarbital |
|
|
What AED drug combination can produce profound sedation?
|
Valproic acid and phenobarbital
|
|
|
What is anticonvulsant hypersensitivity syndrome? What causes it?
|
Derm reactions, fever, and systemic organ involvement caused by phenytoin, carbamazepine, or phenobarbital.
|
|
|
What is the central factor that causes status epilepticus?
|
Failure of GABA to induce inhibition
|
|
|
Why do GABAergic neurons progressively lose function in a status epilepticus event?
|
Excitatory feedback loop causes further decline in function
|
|
|
What drug is use to terminate status epilepticus?
|
diazepam or lorazepam
|
|
|
Which benzo can be given IM to terminate status epilepticus?
|
Midazolam
|
|
|
IV administration of which AEDs is given to maintain control of status epilepticus pts?
|
Fosphenytoin, phenytoin, or phenobarbital
|
|
|
What is the general principle of AED therapy during pregnancy?
|
Seizures are more dangerous than drugs, so treat with lowest possible dose and give mono therapy if possible.
|
|
|
Which AEDs should not be used during pregnancy?
|
Valproic acid
Topiramate Lamotrigine Increased risk of defects with phenytoin, carbamazepine and phenobarbital, but can be safe. |
