Anti-epileptic Drugs Flashcards
What are the two broad MOA of anti-epileptic drugs?
reduce excitability, increase inhibition
What 1 receptor and 2 channels have decreased excitability from anti-epileptic drugs?
Glutamate receptor, Na+ Channel, Ca2+ channel
What is the MOA of phenytoin, carbamazepine, oxcarbazepine, and lamotrigine?
stabilize inactive conformation of Na+ channel
SE of carbamazepine, oxcarbazepine, lamotrigine?
Rash (rarely Stevens-Johnson); slow initial titration important, may cause contraceptive failure
SE of phenytoin?
Rash, gingival hyperplasia, hirsutism, lupus-like reaction, can cause contraceptive failure
Mild myelosuppression, increase LFT
long term- cerebellar degeneration, peripheral neuropathy, osteoporosis
What are carbamazepine and oxcarbazepine used to treat?
complex partial seizures, bipolar disorder and neuropathic pain
What is Lamotrigine used to treat?
generalized epilepsies, absence seizures, bipolar, neuropathic pain
What is phenytoin used to treat?
Acute seizure
tonic/clonic
Toxicities related to Phenytoin? EXAM QUESTION
Dizziness, nystagmus, ataxia, incoordination
Which three Na+ channel blockers are hepatic enzyme inducers?
phenytoin, carbamazepine, lamotrigine
What drug does lamotrigine compete with for excretion?
Depakote (Valproic Acid)
Who can absolutely not be taking valproate? possible exam question
Pregnant women- teratogenicity
SE of valproate?
weight gain, hair turnover, hyperammonemia, blood dyscrasias, teratogenicity
When are benzodiazepines used as anti-epileptic medications?
Status Epilepticus
What can valproate be used to treat?
Broad spectrum use in seizures, IV for status epilepticus, bipolar, migraine, cluster headaches
Name two drugs besides benzodiazepines that GABAergic and used as anti-epileptics.
Vigabatrin and Tigabine
MOA of vigabatrin?
GABA transaminase binder (slows down inrtacellular breakdown of GABA)
MOA of tigabine?
GABA reuptake inhibitor
MOA of GABA analogs?
Block presynaptic influx of Ca2+
Name two GABA analogs.
Gabapentin, Pregabalin
SE of gabapentin?
Sedation
What are gabapentin and pregabalin used to treat?
adjunct for partial complex epilepsy
neuropathic pain
Name two glutamate receptor blockers.
Topiramate and Felbamate
MOA of felbamate
Primarily NMDA receptor blocker
May have effect Na, Ca, GABA
SE of felbamate?
Aplastic Anemia, Acute Hepatic Failure (not used much anymore)
Use of felbamate?
partial onset of seizures, epilepsy
MOA of topiramate?
Primarily AMPA and Kainate Ca channel blocker
May have effect Na, and GABA
SE of topiramate?
mild metabolic acidosis, kidney stones, modest weight loss, acute glaucoma, sedation
Use of topiramate?
partial onset seizures
secondary generalized seizures
primary generalized epilepsy
migraines and cluster headache prevention
MOA of ethosuximide?
blocks t-type ca+ channels in thalamo-cortical circuits
SE of levetiacetam?
well tolerated, mostly sedation
rarely irritabilty, aphasia, thrombocytopenia
Use of ethosuximide?
Absence seizures only
SE of ethosuximide?
nausea, sedation, irritability
MOA of levetiacetam?
binds synpatic vesicle protein 2, leading to less NT release
Use of levetiacetam?
partial onset seizures
secondary generalized seizures
Carbamazepine toxicity?
Dizzy (sedation), drunk (Ataxic), double vision (Diplopia)
Difference between toxicity and adverse reactions?
Toxicity is based on the expected mechanism of action while adverse reactions are not.
