Therapeutics - Epilepsy Flashcards
define epilepsy
RECURRENT seizures (2 or more) that are NOT provoked by neurologic insults (ie - no infection, no previous stroke, no electrolyte imbalance)
just happened unprovoked. electrical activity in brain is inherently abnormal
is a febrile seizure considered an unprovoked seizure
no
there’s a reason behind it
____ withdrawal can cause a seizure
benzodiazepine
name 2 drug overdoses that can cause a seizure
alcohol
barbiturates
hypo ___ and hypo ___ can cause a seizure
hypoglycemia and hypocalcemia
name a particular antidepressant that is a risk factor for seizures
buproprion
the presentation of a seizure depends on what 3 things
-location of onset
-comorbid diseases
-concurrent meds
most people who have a ____ seizure lose consciousness
generalized
what are the 3 types of seizures based on onset
focal
generalized
unknown - dont know if generalized or focal
“focal onset” seizure
starts on ONE SIDE of the brain and may spread to the other side
generalized is on both sides of the brain and the pt tends to lose consciousness
true or false
antiepileptics cannot just be stopped
TRUE - will induce a seizure
must TAPER DOWN
name some drugs that can lower the seizure threshold
antidepressents
neuroleptics
phenothiazines
clozapine, theophylline, isoniazid, cyclosporine, meperidine
name a muscle relaxant that if stopped, can induce a seizure
meprobamate
can antipsychotic withdrawal induce a seizure
yes - particularly the early generations
what is QOLIE-31
what does a HIGH SCORE MEAN
quality of life estimator for epilepsy patients
high score means they have a good quality of life
(low score = low QOL)
true or false
drugs dont cure epilepsy
TRUE - only thing that actually cures epilepsy is surgery
true or false
most epilepsy patients are not on drugs for their life
false - they’re typically on for their whole life
___ is the mainstay of epilepsy treatment
antiseizure drug therapy
when a patient presents after a single, isolated seizure, do we typically treat?
no
typically observe them, see if something induced the seizure
but if the patient has 2 or more UNPROVOKED - that’s when you need to start on antiepileptics
as mentioned, if a patient presents with just 1 seizure we typically dont start antiepileptics.
when may a physician consider starting drugs tho even if they only had 1 seizure
if there is a definite abnormal MRI or EEG
some others tho wait to see if a 2nd one will happen
3 nonpharm options for epilepsy
vagal nerve stimulator (implanted medical device)
ketogenic diet (high fat, low carb)
surgery
vagal nerve stimulator is really only for…
kids who have failed antiepileptic drugs
*when choosing antiepileptic therapy, you ALWAYS start with what
MONOTHERAPY
never start with more than 1
when starting antiepileptic therapy, we should increase the dose until _______
either the seizures stop or CLINICAL toxicity occurs - NOT THE LAB
treat the patient not the level!!!! doesnt matter how low the level is as long as patient doesnt have seizures
everyone has very different antiepileptic medication and dose
___ gen antiepileptics are typically indicated for generalized seizure
early gen
only time ethosuximide is used
absence seizure
name 7 1st gen antiepileptics
carbamazepine
benzos
ethosuximide
phenytoin
phenobarbital
primidone
valproic acid
true or false
the 1st gen antiepileptics are teratogenic
true
true or false
the 1st gen antiepileptics have a wide TI
false - narrow TI
true or false
an advantage of 1st gen antiepileptics is that there are IV formulations available
true
true or false
1st gen are more likely to have DDI, and also need lab monitoring
true
____ has non linear pharmacokinetics
phenytoin
big issue
true or false
1st gen AEDs have less SE than the newer gens
FALSE - more SE
pregnancy cetegory of NEWER antiepileptics
C - good to use in women planning pregnancy
true or false
newer antiepileptics have superior efficacy to older
FALSE - similar
but newer dont need lab monitoring and have better SE profile
true or false
a disadvantage of newer antiepileptics is that there are limited IV formulations
true
**patient has been diagnosed with epilepsy
ONE AED is chosen based on what?
the seizure classification
side effects
insurance
are they male or female? - teratogenicity of the 1st gen
*patient with epilepsy has been started on ONE antiepileptic drug
we send them home, and they come back to follow up
what 2 questions do we ask
are you seizure free?
do you have intolerable side effects?
*pt has been started on 1 AED and they are now following up
when we ask if they are seizure free, they say yes
when we ask if they have intolerable side effects, they say YES
what do we do?
decrease the dose of the drug, and assess them again with the 2 questions later
*patient has been started on 1 AED and they’re now following up
when we ask if they are seizure free, they say yes.
when we ask if they have intolerable side effects, they say no
explain what we do now
assess their QOL questionairre
if optimal, continue the current treatment. if they get to be seizure free for over 2 years, can consider withdrawing the drug (TAPER). if cant get to be seizure free for over 2 years. go back to box 3
if QOL NOT optimal - explore QOL issues and fix them. reassess in a little bit and ask the 2 prime questions again
*patient is started on 1 AED and they’re now being reassessed
we ask if they are seizure free and if they are having intolerable side effects
they are NOT seizure free and they are NOT having intolerable side effects
what do we do?
increase the dose and reassess with the same 2 questions later
*patient is started on 1 AED and are now following up
they are NOT seizure free and ARE having intolerable side effects
what do we do
decrease the dose of the drug and add a second
then we reassess later and ask the same 2 questions
if they’re seizure free, can consider removing the first drug
if they’re not seizure free and having intolerable side effects, remove the least effective drug and add another, and reassess later. if still not seizure free, reconfirm diagnosis and consider nonpharm
if they’re not seizure free and NOT having intolerable SE, increase dose of the 2nd drug and assess compliance
name 3 antiepileptic that really dont inhibit or induce enzymes
gabapentin
lamotrigine
levitiracetam
carbamazepine is a potent CYP3A4 ____
inducer
also an autoinducer- takes like 3-4 weeks to show in lab
true or false
the dosage forms of carbamazepine (chewable/ER/IR) are NOT interchangeable
true
AE of carbamazepine
drowsiness lethargy
rash
hyponatremia
aplastic anemia
osteoporosis
counseling point of something that may happen when carbamazepine is first started
a benign rash on trunk/legs that goes away
monitoring requirements for carbamazepine
CBC and LFT at baseline, and monthyl for 2-3 months
then annually thereafter
BBW carbamazepine
SJS
something you must check before initiating carbamazepine and what to do if positive
HLA-B*1502 allele
DO NOT TREAT IF POSITIVE
only test if certain at risk populations like asians (including south asian indians)
ethosuxamide is only used for what
absence seizures in a3 yrs of age and up
can be mono or adjunct therapy
monitoring for ethosuxamide
CBC (leukopenia, pancytopenia), hepatic and renal function
true or false
the different dosage forms of valproic acid are not interchangeable
true - have diff kinetics
true or false
both valproic acid and carbamazepine are CI in pregnancy
true
BBW valproic acid
hepatotoxicity
advantage of keppra
minimal DDI and comes in XR formulation
SE keppra
worsening depression, anxiety
behavioral changes - aggression
dose keppra need dose adjustment in renal failure
yes
there is cross sensitivity between oxcarbazepine and ____
carbamazepine
so must also check for the allele! to predict SJS
gabapentin usual place in therapy
adjunct therapy
BBW lacosamide
avoid in 3rd degree heart block, and caution in patients with proarrhythmic conditions
true or false
lacosamide has minimal DDI
true
___ is contraindicated in those with sulfa allergy
zonisamide
BBW zonisamide
metabolic acidosis - need to monitor
look for tachycardia, excess fatigue, losing weight
advantage of eslicarbazepine over carbamazepine and oxcarbazepine
longer t1/2 so QD dosing
eslicarbazepine should not be used with…
oxcarbazepine or carbamazepine
if a patient has intolerable psychiatric keppra side effects, what may they be switched to to help
brivaracetam
true or false
perampenal is not a controlled substance
false - it is
BBW perampenal
aggression, homicidal ideation
the IV formulation rate of phenytoin has a max infusion rate
why
hypotension
nystagmus, ataxia, drowsiness, and cognitive impairment are dose-related or non dose related SE?
dose-related
therapeutic range of phenytoin
free drug range
therapeutic range - 10-20mcg/L
free drug - 1-2mg/L
fosphenytoin is the prodrug of phenytoin
what are advantages of using it
minimize problems of IV phenytoin
can be given more rapidly - doesn’t have to be given slowly like IV phenytoin
does not cause hypotension, bradycardia, pain, thrombophlebitis
true or false
fosphenytoin is only given IV
true
BBW felbamate
irreversible fatal aplastic anemia, esp in women
general FDA warning about antiepileptic drugs
suicide risk in epileptic patients from 1 week-24 weeks after starting treatment
**3 drugs that have the lowest incidence of congenital malformations
are any 1 of these better than the other?
lamotrigine
levetiracetam
gabapentin
lamotrigine has an advantage because it can be used as monotherapy
the other 2 are typically adjuncts
if possible ____ is preferred to ____ in women
monotherapy preferred to polytherapy
true or false
in epileptic pregnant patients, you may need to use higher doses
true
2 considerations of things that can be affected in patients on antiepileptics
bone health - osteopenia and osteoporosis. treat with high dose vitamin D and calcium supplements
sexual dysfunction
even if a patient has been seizure free for over 2 years, why might we still want to keep them on therapy
if they have factors associated with recurrent seizures
like a known structural lesion, EEG abnormal, seizure onset during adolescence, neurologic abnormalities, etc
if we decide to take a patient off AED, explain the general rule
~25% taper down every 4 weeks - VERY SLOW
the risk of withdrawal is much lower if we taper down over a whole 6 months rather than just 1-3
brand vs generic considerations AED
not same bioequivalence!!!!!!
even different manufacturers of generics can be a problem - stay consistent
