Antiepileptic Agents Flashcards
Describe epilepsy’s incidence and impact
not a disease, is a condition with an array of symptoms
2nd most common neuronal disorder to stroke
what is an epileptic seizure?
abnormal electrical activity originating in brain
seizures can result in brief episodes of loss of consciousness
- may result in convulsive movements
- disturbances of perception or behavior
what is the basis of a seizure? and progression?
secondary cause: tumor, injury
congenital abnormal site in brain
both lead to abnormal focal activity -> discharge of neurons (increase in sodium, K efflux, Ca2+ influx) -> spread of activity (inhibited by GABAergic neurons, activated by glutamate)
name the two generalized seizures
grand mal (tonic clonic) petit mal (absence seizures)
describe grand mal seizures
1-3 mins
- severe muscle contractions
- aura (warning)
- tonic phase: muscle contraction, extension
- clonic phase: muscle twitching
-loss of consciousness
describe petit mal seizures
most often in children
may end post puberty
brief (5-20 seconds) lapses of consciousness
no alteration in muscle activity (child can have many / day)
Name the two partial type seizures and whether or not loss of consciousness is associated.
simple partial - no loss of consciousness
complex partial - loss of awareness
describe characteristics of simple partial seizure
no loss of consciousness
- focal motor seizures: body motion, complex movements of head / eyes
- sensory seizures: illusions: visual, auditory, olfactory
- behavioral: laughter, nausea, fear, vocal patterns (Tourettes)
may even have post-seizure numbness or blindness
describe characteristics of complex partial seizures
loss of awareness
- staring -> bizarre behaviors
- alteration in feeling or behavior, anger
- associated with amnesia and confusion
what is status epilepticus?
what is administered and how to treat it?
prolonged and repeated grand mal seizures
this is a medical emergency -> death by cerebral anoxia
diazepam IV: low efficacy, depresses CNS but won’t kill
give a brief overview of pharmacologic agents used to treat epilepsy, including how effective they’ve been, general MOA and a significant SE
complete control in up to 50% of px
significant improvement in 25% px
all anti-seizure meds decrease neuronal firing rate in CNS
agents may act on GABA, glutamate or ion channels
significant SE: an increase in suicidal behavior
Name the 5 agents used to treat Grand Mal and Partial seizures
- phenytoin
- carbamazepine
- barbituates: phenobarbital
- benzodiazepines: diazepam (Valium)
- acetazolamide
For what is phenytoin used?
MOA?
Toxicities?
Grand Mal and other types, but NOT petit mal
MOA: inhibits Na+ in brain, slows recovery rate of neurons
- generally not CNS depressant
- relatively low T.I.
Toxicities high dose (acute): resp. depression, cardiovascular collapse, nausea, ataxia
chronic:
- gingival hyperplasia
- vestibular effects: diplopia, ataxia, blurred vision
- some sedation
- teratogenic: fetal hydantoin syndrome
- life-threatening rash: Steven Johnson syndrome
carbamazepine is DOC for what?
MOA?
Toxicities?
does it induce P450?
DOC for partial seizures
MOA: acts on Na+ channels (same as phenytoin)
Toxicities:
- burred vision
- diplopia
- drowsiness
- fetal defect: spina bifida
- aplastic anemia (aplastic: inability of stem cells to produce mature blood cells)
yes, it does induce P450
Name the barbiturate used to treat Grand Mal and partial seizures.
MOA?
SE?
Does it induce P450?
phenobarbital
MOA: activates GABAergic neurons
SE: sedation
strongly induces P450
