antiepileptic drugs Flashcards
1
Q
Na channel blockers (metabolism, toxicities)
A
- highly protein bound
- hepatic metabolism: auto/heteroinduction
- contraceptive failure
- toxicity: sedation, ataxia, diplopia
- adverse rxns: rash, hepatotoxicity, myelosuppression
2
Q
carbamazepine (Tegretol)
A
- Na channel blocker
- toxicity thought to be due to epoxide metabolite
- Tx: complex partial epilepsy, Bipolar, neuropathic pain
- preferred to phenobarbitol, phenytoin, valproate bc of less side effects
3
Q
Phenytoin (Dilantin)
A
- Na channel blocker
- Tx: IV for status epilpticus
- less effective for Absence, Myoclonic or Atonic seizures
- gingival hyperplasia, rash, hirsutism, Lupus-like rxn, dose dependent zero order kinetics
- long term: cerebellar degeneration, peripheral neuropathy, osteoporosis (limit use 1-5 yrs)
- infusion limited by hypotension
4
Q
Oxycarbamazepine
A
- active compound of carbamazepine designed to bypass the toxic epoxide
- less protein bound, less autoinduction, fewer interactions, less toxic, longer half life
- Tx: complex partial seizures, bipolar, neuropathic pain
5
Q
Lamotrigine
A
- Na channel blocker
- effective for all seizures accept myoclonic
- also good for bipolar and neuropathic pain (** think L for Lamotrigine and Lithium = bipolar))
- indication for use in children
- competes for metabolism with Valproate and synergistic effect
- good for long term use
6
Q
Valproate (Depakote)
A
- Na channel and GABA system
- used in everything + migraines and bipolar, IV in status epilepticus
- weight gain, hair turnover, blood dyscrasia, hyperammonemia, teratogenic
7
Q
Gabapentin
A
- GABA analog, inhibits presynaptic influx of Ca current
- Tx: neuropathic pain, adjunctive tx for partial complex epilepsy
- not metabolized: absorption limited at aa transporter in intestines
8
Q
Ethosuximide
A
- blocks T-type Ca currents in thalamocortical circuits
- effective against Absence seizures only
9
Q
Topiramate
A
- AMPA and Kainate Ca channel blockers + activity at Na and GABA channels
- treats all seizures + migraine
- some carbonic anhydrase activity –> weight loss (makes soda taste bad)
- toxicity: cognitive (“word finding”)
- adverse rxns: mild metabolic acidosis –> respiratory compensation –> mild alkalosis –>calcium ioniziation –> tingling; kidney stones, acute glaucoma
10
Q
Levetiracetam
A
- binds to synaptic vesicle protein resulting in less NTM release
- treats all seizures
- well tolerated, little toxicity
- adverse effects: irritability, aphasia, thrombocytopenia
11
Q
Felbamate
A
- blocks NMDA receptor, activity at Na, Ca channels and GABA system
-
aplastic anemia, acute hepatic faiulre (not really used anymore)
**think it fell out of grace
12
Q
benzos
A
- acts at GABA-a receptor
- tx status epilepticus
- long term use limited by tolerance
- short acting due to redistribution
13
Q
Vigabatrine
A
- GABA transaminase binder (slows down intracellular breakdown of GABA)
14
Q
Tigabine
A
GABA reuptake inhibitor
15
Q
pregabalin
A
- GABA analog, inhibits Ca current
- adjunctive tx for partial complex epilepsy
