Antiseizure drugs [3] Flashcards
Seizure vs convulsion
seizure: excessive neuronal discharge
- where antiseizure drugs target - broader
Convulsion: violent involuntary contraction due to excessive electrical activity
Drug to tx partial seizures (focal)
Levetiracetam
(carbamazepine, lamotrigine)
note* simple and complex seizures fall under partial seizures
- more difficult to tx than generalized seizures
Drugs to tx generalized seizures
- Absence:
Ethosuximide, Valproate - Grand mal (tonic clonic)
Levetiracetam (keppra), Valproate, Phenytoin, Carbamazepine
(Lamotrigine)
Broad spectrum antiseizure med
Phenobarbitol
Diazepam (valium)
Valproate (depakene)
Divalproex (depakote)
Tx for status epilepticus
Diazepam (valium) - IV
Lorazapam (ativan)
Midazolam (versed)
ADRs: somnolence
Mechanism of Generalized Tonic-clonic vs Generalized Absence seizures
Generalized Tonic-clonic:
- intiation → loss of GABA tone
- propagation → loss of GABA tone over large areas, plus ↑ response to glutamate and Na+ channel excitation
Generalized Absence seizures
- oscillatory stimulation of thalamic-cortical circuitry - activation of low threshold T- type Ca2+ channels
Why arent Z drugs good against convulsions (bc they do have anti-convulsant properties)
bc you are asleep (hypnotic) before you get the anticonvulsant effects
- BDZ are good
MOA
- Ethosuximide
- Lamotrigine
- Levetiracetam
Ethosuximide
- blocks the low-threshold T-type Ca2+ channels in thalamocortical pathways
Lamotrigine
- blocks high voltage VSCC (that is involved in reg of Glu release)
- blocks VSSC (suppress repetitive APs)
Levetiracetam
- Inhibits synaptic vesicle protein SV2A
- impairs Ca2+ mediated NT release
MOA Valproic acid Diazepam Phenytoin Carbamazepine
Valproic acid
- enhancement of Gaba activity
Diazepam
- enhancement of GABA activity
Phenytoin
- blocks VSSC (suppress repetitive AP)
Carbamazepine
- blocks VSSC (suppress repetitive AP)
Which antiseizure can cause gingival hyperplasia. List its MOA
Phenytoin
- blocks VSSC (suppress repetitive AP)
Agranulocytosis
Clozapine
1st line tx in generalized tonic clonic
Levetiracetam (keppra)
others: Valproate, Phenytoin, Carbamazepine
(Lamotrigine)
Do we have a higher incidence of anxiety disorders or major depressive disorders?
anxiety
incidence of bipolar mania and depression
Black box warnings for Carbamazapine and Valproate (depakote)
Hepatic failure –> death
- monitor Liver Function Test
Classic enzyme inducer
phenobarbital
Broad spectrum antiseizure med
Good for difficult to tx seizures
(carbamazepine and phenobarbital also induce enzymes)
Anticonvulsive agents will result in additive CNS depression (increased somnolence) when given with what?
Opiod analgesics
(these are all anticonvulsives:
- phenytoin
- carbamazepine
- Phenobarbital
- Diazepam
- Levetiracetam
