Absence seizure meds and Broad spectrum antiepileptics Flashcards
Ethosuximide mechanism
Inhibits T-type Ca++ channels in the Thalamus
What are the characteristics of an absence seizure
short staring freezing and blinking for 2-10 seconds, can occur hundreds of times a day
3Hz spike pattern on the EEG
Ethosuximide SEs
Very well tolerated as far as antiepileptics go.
- GI distress, cramps
- Lethargy
What are the broad spec antiepileptics
Valproate
Topiramate
Lamotrigine
Levetriacetam
(and Clonazepam)
Valporate mechanism
Inhibits voltage gated Na channels
Inhibits GABA transaminase, increasing GABA
Topiramate mechanism
Na, Ca, GABA, NMDA channels, and Carbonic anhydrase
Inhibits voltage gated Na channels
Inhibits high voltage activated Ca channels
Allosterically activates GABAa channels
Inhibits carbonic anhydrase.
May also inhibit NMDA channels
Lamotrigine mechanism
Inhibits:
voltage gated Na channels
high voltage gated Ca channels
decreases glutamate release
Levetiracetam mechanism
UNKNOWN
Almost NO drug interactions and is a great adjunct treatment for all seizure types except absence
Valproate SEs
- Nausea, vomitting
- Weight gain
- Tremor
- Teratogenic, neural tube defects
Rare but possibly FATAL SEs:
Acute hepatotoxicity
Acute Pancreatitis
Topiramate SEs
Fatigue,
Weight LOSS
Kidney stones
Acute myopia and Closed angle glaucoma
Decreased sweating, heat intolerance
Lamotrigine SEs
So slow onset and tirtation up is important
10% get a benign skin rash,
1% get life threatening SJS
Cross eyed diplopia
Metabolism of the broad spec antiepileptics
Liver CYP substrates
Levetiracetam SEs
Fatigue, somnolence
Mood changes
Doesn’t have ANY drug interactions, is a great adjunct treatment for seizures.
