anti seizure drugs Flashcards
what is the mechanism for Bilateral tonic-clonic (aka primary generalized onset seizures)
Initiation occurs locally with loss of GABA inhibitory tone, propagation due to decreased GABA tone over large area / increased response to glutamate / Na+-channel excitation
what is the mechanism for absence seizures
Related to oscillatory stimulation of thalamic-cortical circuitry; inappropriate activation of low-threshold T-type Ca++ channels
what are the 3 primary drugs to treat Primary Generalized Tonic-Clonic seizures
Valproate OR Lamotrigine OR Levetiracetam
what are the 2 primary drugs for absence seizures
Ethosuximide OR Valproate
what are the 3 drugs for Myoclonic seizures
Valproate
Lamotrigine
Clonazepam
what drugs can make myoclonic seizures worse
gabapentin and carbamazepine
what 4 AED’s block voltage dependent sodium channels and reduce repetitive firing, thus better at controlling tonic-clonic seizures
Phenytoin,
carbamazepine,
lamotrigine,
topiramate
what does ethosuximide do?
Decreases low-threshold Ca++ (T-type) current (oscillatory responses in thalamic neurons). These Abnormal currents are involved in absence seizures;
Levetiracetam binds to and inhibits function of synaptic vesicle protein ______ in Ca++-mediated neurotransmitter release. Relation to antiseizure action is uncertain
SV2A
Rash & gingival hyperplasia are side effects of which drug?
Phenytoin
Levetiracetam has no ______ drug metabolism, and minimal drug interactions
P450
•Levetiracetam is First-line drug in treatment of generalized ______ seizures and partial onset seizures
tonic-clonic
Topiramate is Used as adjunctive therapy in _______ seizures
partial
in which drug is Renal stones possible (due to mild carbonic anhydrase inhibitor).
Zonisamide
________ Inhibits Na+ channel function via enhancement of slow inactivation without blocking channel directly in contrast to other AEDs that prolong fast inactivation
Lacosamide
Drug of choice in absence (petit mal) seizures is ______
Ethosuximide
Valproic acid Limits activity of _______
T-type Ca++-channels
Valproic Acid has drug interactions with Aspirin / warfarin that can _____.
inhibit platelet aggregation
which drug is Designed as a lipid-soluble GABA analog to cross blood brain barrier, but does not act directly at GABA receptors. Binds to α2δ subunit of voltage-sensitive Ca++ channels, may act to decrease synaptic release of glutamate producing its anticonvulsant activity
GABApentin
define Status Epilepticus
state of recurrent major motor seizures between which a patient does not regain consciousness
describe the Initial therapy for status epilepticus
IV lorazepam, until seizures stop or 20 mg given, then start phenytoin or fosphenytoin NTE 50 mg/min (20 mg/kg IV push or infusion), slow infusion if hypotensive
Which 2 anti-seizure drugs may have the highest risk for fetal malformations.
Valproate and phenobarbital
Risk of birth defects (cleft palates, skeletal abnormalities, CNS/cardiac problems) _____ higher if mother on anticonvulsants, but ______ deliver normal babies
2-3-fold ,
> 90%
what are the main side effects of Phenobarbital
Irritability and overactivity in many children,
sedative effects in others (tolerance can develop).
May interfere with learning (cognitive deficits)
