AEDs Flashcards
(18 cards)
classical AEDs
phenytoin, carbamazepine, ethosuximide, valproic acid
newer AEDs
oxacarbazepine, gabapentin, lamotrigine, topiramate, levetiracetam, zonisamide
classical AED with the least sedation
valproic acid
cons of classical AEDs
- decreased bone mineral density
- increase metabolism of BC
- teratogenic
- hypersensitivity- skin rxns; hematotoxicity
- multiple doses/day
- long half lives
- recommended TDM
a number of classical AEDS contains
the ureide structure
phenytoin (Dilantin) MOA
slows rate of recovery of Na channels
- effective in partial & tonic-clonic seizures
phenytoin elimination
- rate of elimination varies as a function of its concentration
- half-life increases with dose increase
- [drug] in plasma increases disproportionately when dose is increased
- age dependent metabolism
phenytoin ADRs
cns depression, gingival hyperplasia, osteomalacia, megaloblastic anemia, hirsutism, hyperglycemia, teratogenic
carbamazepine (Tegretol)
- slows recovery of Na channel
- primary drug for partial and tonic-clonic seizures
- induces its own metabolism
carbamazepine ADRs
- acute intoxication
- long term therapy- drowsiness, vertigo, ataxia, diplopia, blurred vision
- seizure may increase with overdose
- N/V
- hematological
- retention of water in the elderly, teratogenic, skin rxns (SJS & TEN)
ethosuximide (Zarontin)
- blocks T type channels in thalamus
- first line for absence seizures
- GI & CNS problems
valproic acid (Depakene)
- multiple actions- Na & Ca channel blocker, enhances GABA transmission
- DOC for unclassified forms of seizures
- GI, weight gain, hair loss
oxacarbazepine (Trileptal)
- blocks Na channels
- can be effective in pts who didnt respond to cbz
- prodrug
- decreases plasma levels of eithinyl estradiol & levonorgestrel
Gabapentin (neurontin)
- GABA molecule bound to a cyclohexane ring, but does NOT mimic GABA
- MOA not well understood, promotes release of GABA at synapse
- useful in neuropathic pain, migraine, spasticity
- no known interactions with other AEDs
- no metabolism
- used as a second line adjunct
lamotrigine (Lamictal)
- delays Na channel recovery
- not an enzyme inducer
- anti-folate acticity
- mono & adjunct therapy
- mood stabilizer
topiramate (Topamax)
- multiple MOA- blcosk AMPA, NA channels & activated hyperpolarizing K channel
- mono & adjuncttherapy
- adr: cognitive impairment w/ too fast titration
- teratogenic
levetiracetam (Keppra)
- unknown MOA
- myoclonic, partial & tonic-clonic >4yo
- eliminated renally mostly unchanged
- modest side effects
- limied evidence for anti-epileptogenic properties
Zonisamide (Zonegran)
- blocks Na & T-type Ca channels
- adjunct for partial seizures
- 85% renal elimination unchanged
- long half-life
- no interactions
