Ott Seizures Flashcards
what are the two main types of seizures
partial and generalized
what are the two kinds of partial seizures
simple and complex
what are the types of generalized seizures
tonic
clonic
tonic-clonic
absence
atonic
myoclonic
what medications at usual doses can lower the seizure threshold
bupropion
clozapine
theophylline
varenicline
phenothiazine antipsychotics
CNS stimulants
what medications at high doses can lower seizure threshold
carbapenems
lithium
meperidine
penicillin
quinolones
tramadol
what quality of life monitoring should be taken for seizure patients
frequency
functional status
social functioning
mental health status
cognition
# of doses of drugs per day
cost of drug therapy
what are the risk factors for seizure recurrence
<2 years seizure free
onset of seizures after 12
history of febrile seizures
2-6 years before good seizure control
more than >30 seizures before control
partial seizures
abnormal EEG
organic neurological disorder
withdrawal of phenytoin or valproate
what are possible reasons for treatment failure
failure to reach CNS target
alteration of drug targets in the CNS
drugs missing real target
management of drug resistant epilepsy
rule out wrong drug or diagnosis
combination therapy
electrical/surgical intervention
definition of status epilepticus
continuous seizure activity lasting 5 minutes or more or 2 or more discrete seizures with incomplete recovery between seizures
what is first line for status epilepticus
IV benzodiazepines (lorazepam or midazolam)
what is phenytoin’s biggest risk
hypotension - limits infusion rate
fosphenytoin compared to phenytoin
prodrug and better IV tolerance
fosphenytoin equivalents
20mg PE/kg IV
what is required for phenytoin and fosphenytoin
cardiac monitoring and purple glove syndrome
oral phenytoin dosing considerations
MUST obtain both phenytoin serum concentration and serum albumin in same blood draw
what is the goal serum concentration of oral phenytoin
10-20mcg/ml
Valproate loading dose IV to PO conversion
1:1 mg/kg
Valproate goal serum concentration
80mcg/mL (50-125 mcg/ml)
1A2 inducer
carbamazepine
phenobarbital
phenytoin
2C9inducer
carbamazepine
phenobarbital
phenytoin
3A4 Inducers
Carbamazepine
Cenobamate
Clobazam
Eslicarbazepine
Felbamate
Lamotrigine
Oxacarbazepine
Phenobarbital
Phenytoin
Primidone
Rufinamide
Stiripentol
Topiramate
Oral Contraceptives
UGT inhibitors
Valproate
Lamotrigine without concomitant UGT drug interactions
25mg qd x 14 days
50mg qd x 14 days
100mg qd x 7 days
200mg qd
Lamotrigine with UGT inhibitor (valproate)
halve the dosing
25mg every other day x 14 days
25 mg qd x 14 days
50mg qd x 7 days
100mg qd
Lamotrigine dosing with UGT inducers (carbamazepine, phenytoin)
double the dosing
50mg qd x 14 days
100mg qd x 14 days
200mg qd x 7 days
400mg qd
what is the boxed warning for lamotrigine
stevens-johnson syndrome/toxic epidermal necrolysis
what is the black box warning for carbamazepine or derivatives
genetic screen for HLA-B*1502 allele prior to starting
what should happen with patients who test positive for the HLA allele
should not be treated with carbamazepine or derivates unless benefit outweighs risk
what is strongly correlated with HLA
AHS in patients of Asian descent
what is DRESS syndrom
potentially life-threatening drug reaction with eosinophilia and systemic symptoms of drug induced hypersensitivity
when does DRESS syndrome occur
2-6 weeks after drug initiation
what drugs are associated with DRESS syndrome
carbamazepine, cenobamate, lamotrigine, phenobarbital, phenytoin, valproate, zonisamide
what patients are at an increased risk of DRESS syndrome
positive for HLA-A*3101 allele (asian or northern european descent)
what is antiseizure withdrawal syndrome associated with
abrupt discontinuation of antiseizure meds
what is the danger of antiseizure drug withdrawal syndromes
recurrence of seizures
why are drug serum concentrations altered in pregnancy
changes in volume of distribution
what should seizure patients who are child bearing age be aware of
most seizure drugs are teratogenic and contraceptives should be used (keeping in mind OC drug interactions)
what antiseizure drug is not recommended in pregnancy and why
valproate because it causes neural tube defects and is associated with a decreased IQ in offspring
what should be given with antiseizure drugs in pregnancy
supplemental folic acid (5mg daily)
supplemental vitamin K 10mg daily during last month of pregnancy
infant get vit K 1 mg IM at birth
what is the contraceptive drug interaction mediated by
P450 3A4 induction
how can contraceptive drug interactions be minimized
use higher-dose estrogen contraceptives - warning for increased thromboembolism
what contraceptives are recommended
IUDs and depot
how does estrogen affect lamotrigine
significantly decrease lamotrigine serum concentration 50% and lamotrigine decreases estrogen concentrations
what drug is associated with arrhythmias
lamotrigine
phenytoin/fosphenytoin
what drugs cause PR interval changes
lacosamide
pregabalin
what drug causes heart block
lacosamide
what drug is associated with valvular hear disease
fenfluramine
what are the AEs of carbamazepine/eslicarbazepine/oxcarbazepine
hyponatremia, SIADH
what are the AEs of phenytoin
altered vit d metabolism and decreased calcium concentrations leading to osteoporosis with long-term use
what side effects does topiramate have
decreased bicarb leaded to metabolic acidosis
nephrolithiasis
decreased sweating
heat intolerance
oligohydrosis
what are the psych AEs of levetiracetam
psychosis
suicidal thoughts
unusual mood change
worsening depression
what are the psych AEs of perampanel
boxed warning: dose related serious psych events
what are the psych AEs of valproate
acute mental status changes related to hyperammonemia
what are the psych AEs of topiramate
associated with cognitive dysfunction if the dose is increased too rapidly so use slow titration
what drug can cause visual abnormalities
topiramate
