Wk 11 Seizures Flashcards
causes of seizures
congenital defects (cerebral palsy), hypoxia, trauma, CA, alcohol/drugs (includes withdrawal), inc body temp, electrolyte disturbances and glucose abnormalities
drug causing seizures
Meperidine
seizure type info
identification is important
initial drug choice is type dependent
wrong choice may precipitate seizures
primary drug for all seizures
Valproate
carbamazepine and phenytoin
secondary meds for all partial seizures and generalized tonic-clonic seizures
anti-Epileptic Drugs
most respond to 1-2 rarely req > 2 50-70% controlled with monotherapy 30% req combo therapy 5% poorly controlled despite therapy
pseudoresistance
caused by wrong dx, wrong drug, wrong dose or lifestyle issues
must be r/o to consider tx failure
goal of AED therapy
prevent seizures, maintain normal fun and improve quality of life with FEWEST SE’s!
principles of AED therapy
select a drug recommended for identified seizure type (wrong one can cause seizures)
when augmenting therapy, chose drug with alternative mech
optimal tx requires individualization
D/C’ing AED therapy
depends on seizure type, seizure-free duration, EEG and other factors
NVR abruptly D/C an AED (should taper)
sudden withdrawal may precipitate Status Epilepticus
relapse likely if done over 1-3 mo’s (less likely if over 6 mo’s)
when to start AED
highly individualized
immediate therapy rarely needed after single seizure
start in pt’s at risk for recurrent
generally start after 2 or more unprovoked seizures
NOT necessarily lifelong
common interactions with AED’s
oral contraceptives, warfarin
very sig CYP450 inducers
less sig CYP450 inducers
much less significant (newer 2nd gen agents)
common SE of AED therapy
CNS (sedation, slowed thinking, dizziness, ataxia), Osteomalacia and OP
correlate drug levels to symptoms before abandoning med
combo therapy
whenever possible, mono therapy is preferred (inc adherence, provides wider therapeutic index, cost effective)
choose an add-on with different MOA and/or diff SE profile
negative for combo therapy
combos promote drug-drug interaction
no controlled studies comparing drug combos
big three meds
phenytoin, carbamazepine and valproic acid
Phenobarbital
rarely used now, was anticonvulsant drug of choice in preg
if going to use, supplement young females with 1-4 mg folate/day
other drugs as effective, fewer SE’s
primidone is metabolized to phenobarbital
other uses of AEDs
neuropathic pain (Gabapentin and pregablin) BP disorder and migraine
status epilepticus
life-threatening ER
mortality ~20%
et of status epilepticus
AED noncompliance/D/C
withdrawal syndromes
brain injury
metabolic abnormalities (dec glu, Ca, Na, etc)
drug use/overdose that lower seizure threshold
drugs that lower seizure threshold
imipenem (LESS with meropenem merrem)
high dose Pen G (IV PCN)
lidocaine
Lorazepam
easier to use than diazepam + phenytoin and phenobarbitol
most effective in terminating seizure within 20 min and maintaining seizure-free in first 60 min after tx
may be diluted with = vol of 0.9% NaCl
phenytoin for status epilepticus
better results at higher dosing (18-20)
mayweed to slow infuse dur to hypotension
fosphenytoin for status epilepticus
highly water soluble, unlikely to precipitate
