Part II: Seizures Flashcards
difference between partial and generalized seizures
no LOC, localized to specific area of brain with partial
Generalized always involves LOC and include Tonic-clonic or Absence (T-Type Ca Channels normally active during sleep) or Status Epilepticus
Types of Generalized seizures
Tonic-clonic: focal an spreads in one hemisphere throughout the brain
Absence: brief interruptions of consciousness seen as motionless staring, in school-aged kids, non-synchronized thalamocortical/cortical cells, activation of T-Type Ca Channels normally active during sleep
Status Epilepticus: can be either absence or tonic-clonic, 5 minutes w/out regaining consciousness
Mechanisms for anti-seizure drugs
Prolong inactivation of Na channels which reduces ability of neurons to fire at high frequency
Enhance GABAergic Activity to increase receptor response to GABA, or increase synaptic availability of GABA
Inhibiting T-Type Ca Channels
Decreasing Excitatory Neurotransmission by binding alpha delta subunit or VGCaC in the CNS or enhance K channel opening
What is the DOC for status epilepticus and why
Diazepam: it can be given IV, good anti-convulsant. Only limited by tolerance acquired within 2-3 weeks
- Tonic clonic DOC
- Precipitates status epilepticus, sedation, ataxia if abruptly stopped
- Teratogenic
Phenobarbital: enhances GABAa receptor responses
- Parent and products are active as anticonvulsants
- Effective in patients not responding to phenytoin or phenobarbital
- Is given w/ phenytoin but never phenobarbital
Primidone
- Prolongs inactivation of Na channels to decrease glutamate release
- DOC for tonic-clonics and partial seizures
- Less sedating than barbiturates
- Hyperplasia of gums
- Many drug interactions
Phenytoin (hydantoin)
Phenytoin is a teratogen that can cause
Fetal Hydantoin syndrome
What drug for seizures inactivates Na channels and inhibits T-type Ca Channels
Valproic Acid
can cause hepatotoxicity in really small children
Valproic acids, unlike the other anti-seizure drugs that induce P450, it _______d
Inhibits P450
Carbamazepine is DOC for
partial seizures
Anti-seizure that increases inactivation of Na Channels and decreases release of glutamate that is the DOC for partial seizures
induces microsomal enzymes
causes blood dyscrasias and is possible teratogen
Carbamazepine
Increases inactivation of Na channels and Ca channels and decreases glutamate release
not protein bound
Lamotrigine
Drug that increases inactivation of Na channels, with SE profile including sedation, mental dulling, nausea, abnormal vision, parasthesia, decreased bicarb secretion
may decrease efficacy of oral contraceptives
Topiramate
Partial seizure treatment
Levetiracetam (binding to synaptic vesicular proetin SV2A), lacosamide, Gabapentin/Pregabalin
