Flashcards in 11. Anti-Epileptic Drugs PHARM Deck (36)
what is the single most effective drug for generalized epilepsy?
what drug is best for childhood petit mal/absence?
what are best for child-bearing women?
metaphorically, levetiracetam is considered to be what?
the swiss army knife of anti-epilepsy drugs: works for everything, does nothing really well, favorite in hosp settings
what is the single most effective drug for focal epilepsy?
what is equally effective to carbamazepine for focal sz, but has a worse side effect profile?
why do barbutuates have a high drop out rate?
what drug is best in the elderly? why?
lamotrigene. less sedating than others, few drug interactions.
opening of Ca2+ and Na+ channels tend to produce what in the neuron?
depolarization (both flow in, make interior less negative)
opening of K+ and Cl- channels tend to produce what in the neuron?
hyperpolarization (K flows out, makes interior more neg. Cl flows in, makes interior more neg)
what does GABA do?
inhibitory. opens a Cl- channel, hyperpolarizes the cell. makes firing less likely
what does glutamate do?
excitatory. binds to receptors, opens Na+ and Ca2+ channels. depolarize cell, make firing more likely
what drugs are agonists of GABA receptors?
benzodiazepines, barbituates, topiramate
what drugs are antagonists of glutamate?
drugs that block Na+ channels are inhibitory or exitatory?
what drugs block Na+ channels?
phenytoin, carbamazepine, valproate, topiramate, lamotrigine
what is the mechanism of action of ethosuximide?
blocks T-type Ca2+ channels in thalamus. effective because absence seizure is an uninterrupted cortico-thalamic circuit.
how many half-lives does it take to reach steady state?
what will be the effect of an INDUCER of CYP-450?
it will incr clearance and decrease concentration of other drugs
what will be the effect of an INHIBITOR of CYP-450?
it will decr clearance and increase concentration of other drugs
considerations of pharmacodynamics in preg?
incr volume due to hemodilution, higher doses usually needed, faster metabolism
what other drugs may be less effective when taken with AEDs?
OCPs, coumadin, anti-depressants, cholesterol-lowering drugs, chemo (due to enzyme induction)
Side effects of AEDs (systemic)?
GI problems (1-10%)
side effects of AEDs (CNS)?
depressants, sedatives, fatigue, headaches, blurred vision, double vision
PCOS: worst AED for this? what should she switch to?
valproate is worst. switch to lamotrigine.
AEDs: cause osteoporosis?
yes: phenobarbital, phenytoin, carbamazepine. supplement with Ca and Vit D
phenobarbitol: seizure types? Mech?
all except absence. IV for useful for status epilepticus. GABA agonist: opens Cl channel
Phenytoin: seizure types? mech?
all except absence, better for focal/secondarily generalized. Blocks VG Na+ channels.
need to supplement Ca.
Benzodiazepines: seizure types? mech?
acute seizure control, not good long term due to tolerance. first line for status epilepticus or alc withdrawal.
agonist at GABA
Carbamazepine: seiz types? mech?
first line for focal epil. also mood stabilizer and good for neuropathic pain. Na channel blocker. sig weight gain.
ethosuximide: seiz types? mech?
only for absence seizures. blocks T type Ca channels in thalamus
Valproate: seiz types? mech?
first line for generalized epil. Na channels. also: migraine, bipolar. very bad for preg women.
gabapentin: seiz types? mech?
partial and secondarily generalized. incr GABA in the brain. also anxiolytic, sedative, good for neuropathy
lamotrigine: seiz types? mech?
broad spectrum, all sz types. good for preg women. rash can lead to liver necrosis.
also bipolar, neuropathic pain
topiramate: seiz types? mech?
all but absence. causes weight loss. sedation. mult mechanisms.