antiepileptic drugs Flashcards
1. List prototype drugs for the major classes of antiepileptic drugs, describe their mechanism of action, spectrum of antiepileptic activity, and list their major side effects. 2. Describe the metabolism and elimination of the prototype antiepileptic drugs and the possible drug interactions. 3. Describe the signs and symptoms of status epilepticus and its treatment.
SE of Na+ channel blocking AEDs
diplopia, nystagmus, ataxia, vertigo, sleepiness, cognitive slowing
phenytoin class
Na+ channel blocking AED
carbamazepine class
Na+ channel blocking AED
valproic acid class
Na+ channel blocking AED
phenobarbitol class
Na+ channel blocking AED/GABAA
Lamotrigine class
Na+ channel blocking AED
topiramate class
Na+ channel blocking AED
zonisamide class
Na+ channel blocking AED
phenytoin metabolism
liver (P450),
drug that is 1st order initially then slows to zero order
phenytoin
drug that causes gum hyperplasia
phenytoin
drug that causes osteopenia
phenytoin
drug that causes dose dependant neutropenia
carbamazepine
drug that autoinduces P450
carbamazepine
drug that has a metabolite that is active against seziures but increases adverse effects
carbamazepine
drug to use if you cant tell if seziures are partial or generized
valproic acid
drug that inhibits hepatic metabolism of other AEDS
valproic acid
MOA of valproic acid
blocks Na+, also T-type Ca++ channels, and may effect GABAA
Adverse Effects of valproic acid
weight gain, tremors, hair loss, jaundice
fat, bald, shaky and yellow
valproic acid
drug used as adjunctive therapy for partual and GTC seziures
lamotrigine
drug that can cause rash, up to stevens=johnson
lamotrigine
adverse effects of topiramate
confusion/psychosis, renal stones
Na+ channel AED excreted by the kidney
topiramate
drug NOT to give in pt with hx of kidney stones
topiramate
lacosimide class
Na+ channel AED, (2nd generation)
how benzos help seizures
enhance GABAA channel
benzos used for seizures
diazapam, lorazepam, clonazepam
barbos used for seizures
phenobarbital
drugs that have GABA secondary effects
topiramate, gabapentin, valproic acid
metabolism of clonazepam
hepatic
SE of clonazepam
sedation, ataxia, psychosis, memory problems
AED that can worsen seziures when tolerance occurs
clonazepam
AED that is rapidly absorbed to fat
diazepam
drug used to treat status epilepticus
diazepam
problem with using diazepam longterm
marked sedation and tolerance
SE of phenobarbital
cognitive slowing, hyperactivity in kids
AED with the worst cognitive slowing effects
phenobarbital
type of drug used for absence seizures only
T channel Calcium channel agents
type of seziure that generates 3 Hz spike and wave pattern
absence
MOA of T channel Ca++ channel AEDs
hyperpolarsing channels that generate rhymic pacemaker activity in thalmus
DOC for absence seizures
ethosuximide
drugs that can be used for absence seizures
ethosuximide, valproic acid, zonisamide, lamotrigine
drug that can ONLY be used against absence seizures
ethosuximide
SE of ethosuximide
GI irritation, lethargy
site of ethosuximide metabolism
liver
gabapntin MA
binds to Ca++ a2g subunit and impedes excessive synaptic glu release
adverse effects of gabapentin
sedation, ataxia, weight gain, peripheral edema
AED used off label for neuropathic pain
gabapentin
MOA of levatiracetam
bids to SV2A synaptic vesicle protein
adverse effects of levatiracetam
somnolence, ataxia, irritability
do you treat with AEDs after an initial seziure
no
better idea, combo therapy or pushing one drug to toxicity
monotherapy
DOCs for partial seziures
carbamazepine, penytoin, lamotrigine
DOC for absence only
ethosuximide
DOC for absence + other type
valproic acid
DOC for primary generalized seizures
valproic acid, lamotrigine, topiramate, levetiracetam
carbamazepine + phenytoin =
lower levels of both drugs
erythimycin + phenytoin =
phenytoin toxicity
general effect of AEDs on many drugs
may slow clearance by slowing glucuronidation
AEDs that are P450 inducers
pehnobarbital, phenytoin, carbamazepine
AED that can cause neural tube defects
valproic acid and carbamazepine
DOC for status elipticus
IV benzo, plus IV fosphenytoin