Seizure/Epilepsy Flashcards
acute management, chronic management, monitoring, DDI, ADE, pregnancy, peds, counseling points
drugs that can lower the seizure threshold
bupropion
clozapine
metoclopramide
theophylline
beta lactams
lithium
meperidine
FQs
tramadol
methadone
first line for acute seizure management
***if sz lasts >5 min
for 5-20 min
IV ativan or IV midazolam (versed) or rectal diazepam (Diastat)
for 20-40 min
give regular AEDs
keppra
VPA
IV fosphenytoin
IV phenytoin
phenobarbital
what doses does diastat (PR diazepam) come in
2.5mg
10mg
20mg
what is the device that can monitor sz in patients >6 yo
Embrace 2 smart watch
what type of diet can possible help with epilepsy
ketogenic
4:1 fats : carbs + proteins
what are the general coverage AEDs
keppra
lamotrigine
VPA
topiramate
how is lamotrigine dosed upon initiation for patients not on CYP inducers or inhibtors
week 1-2: 25mg po qd
week 2-4: 50mg po qd
week 5+: increase daily dose by 50mg q1-2 weeks
why is lamotrigine titrated slowly
risk of SJS/TEN
ADE of lamictal
SJS/TEN, DRESS, blood dyscrasias, arrhythmia, HLH, alopecia, N/V, somnolence, tremor, blurred vision
what color lamotrigine starter kit would be used for a patient on VPA
blue with a lower starting dose
what color lamotrigine starter kit would a patient use if they are not on any CYP inducers or inhibitors that affect lamotrigine
orange
what color lamotrigine starter kit would a patient be started on if they were taking a drug that induces CYP enzymes that affect lamotrigine concentrations and no VPA
green with a higher start dose
(phenobarbital, phenytoin, rifampin, SJW, primidone, carbamazepine)
levetiracetam dosing
start dose
MDD
renal adjustments?
what is the IV:PO ratio
start 500mg IR BID
MDD 3000mg
CrCl <80 –> dec dose
1:1
ADE of keppra
irritability, HTN, SJS/TEN, psych reactions, somnolence
levetiracetam DDI
no significant DDI :)
topiramate dosing
start dose
MDD
renal adjustments?
what is the IV:PO ratio
week 1: 25mg IR BID
week 2:-4: inc TDD by 50mg
week 5+: inc by 100mg weekly
MDD 400mg
CrCl <79 –> dec dose 50%
not available IV!
when is topiramate contraindicated
Er formulations are CI with alcohol and metformin
topiramate SE and monitoring
metabolic acidosis, nephrolithiasis, angle-closure glaucoma, memory issues, psychomotor slowing, anorexia, fetal harm
monitor bicarb, s/sx kidney stones, renal function (dec dose 50% if CrCl <80), hydration, eye exams for glaucoma
topiramate and CYP DDI
topiramate is a 3A4 inducer
3A4 inducers also dec topiramate levels
topiramate decreases efficacy of
estrogen-containing oral contraceptives and warfarin
what is the starting dose of VPA
15-20 mg/kg/day
MDD of VPA
60mg/kg/day
VPA concentrations are reported as
A. free
B. bound
C. total
C. total
VPA TDM goal
50-100mcg/mL of total VPA
what is the nuance with TDM of VPA
dec albumin will inc unbound VPA while VPA level stays the same bc it is total VPA
BBW of VPA
hepatic failure, fetal harm and neural tube defects
when is VPA contraindicated
hepatic disease
VPA SE and monitoring
SE: hyperammonemia, thrombocytopenia, DRESS
monitor: LFTs, CBC w diff, plts, TDM
T or F
carbapenems increase VPA concentrations
false, carbapenems dec VPA concentrations by induction
T or F
estrogen containing oral contraceptives decrease VPA concentrations
true, carbapenems do as well
T or F
VPA inhibits 2C9
true
T or F
VPA inhibits 2C19
false, VPA is a substrate of 2C19
what are the common inducers of VPA metabolism
phenytoin
phenobarbital
rifampin
carbamazepine
T or F
SJ Wort induces VPA metabolism
false, does not affect
which AEDs are metabolized by 2C19
VPA
lacosamide
phenytoin
esomeprazole and omeprazole will increase or decrease VPA concentrations? Which enzyme is involved?
esomeprazole and omeprazole inhibit CYP2C19 and will increase VPA concentrations
VPA will increase plasma concentrations of… via 2C19 inhibition
SATA
A. warfarin
B. lacosamide
C. rifampin
D. phenytoin
E. amiodarone
F. statins
A. warfarin
B. lacosamide
D. phenytoin
which are the narrow spectrum AEDs
phenytoin, fosphenytoin, lacosamide, oxcarbazepine, carbamazepine, phenobarbital
lacosamide isa control - _____
V
pregabalin is a control - ____
V
lacosamide
brand name
control - ___
vimpat
V
phenobarbital is a control - ____
IV
lacosamide starting dose
MDD
renal adjustments?
IV:PO
50-100mg BID
MDD 400mg
MDD if CrCl <30 = 300mg
1:1
major lacosamide ADE
porolongs PR interval –> arrhythmias
*caution with BB, CCB, and other drgs that prolong PR interval
carbamazepine brand name
TDM goal
tegretol
goal is 4-12 mcg/mL
tegretol (carb) ADE and monitoring
DRESS SJS/TEN, liver damage, fetal harm, hyponatremia
what should be done prior to tegretol or trileptal initiation and for which patient population?
patients of asain ancestry should be tested for the HLA-B*1502 allele
what is a major concern with tegretol and trileptal
hyponatremia (SIADH)
how do we convert between oxcarbazepine and carbamazepine
carb x 1.2 or 1.5 = oxcarb
carbamazepine is CI in
myelosuppression
MAO-i in last 14 days
TCA hypersensitivity reaction
what is unique about carbamazepine metabolism
auto inducer
enzyme inducer and induces its own metabolism
oxcarbazepine
dosing
MDD
renal adjustments
warnings
300mg BID
MDD 2400mg
CrCl <30 – start at 300mg qd
warnings: SJS/TEN, hyponatremia
carbamazepine/tegretol
dosing
MDD
renal adjustments
warnings
200mg BID
MDD 1600mg
no renal dose adjustments
warnings: SJS/TEN, hyponatremia
phenytoin dosing
target in TDM
LD = 15-20mg/kg LD
TDM 10-20 total
1-2.5 free
corrected pheny equation
corr pheny = pheny measured
(0.2 x alb) + 0.1
IV:PO phenytoin
1:1
admin of IV phenytoin should not exceed
50mg/min
Fosphenytoin is a ____________ of phenytoin
prodrug
how to convert btwn Fosphenytoin and phenytoin
1.5mg Fosphenytoin = 1mg phenytoin
admin of IV Fosphenytoin should not exceed
150mg of phenytoin equivalent/min
s/sx of phenytoin dose-related toxicity
nystagmus, ataxia, diplopia, lethargy
s/sx of chronic phenytoin use
gingival hyperplasia
hair growth
liver tox
inc BG
metallic taste
what should be monitored with phenytoin use
ECG (arrhythmias)
CMP
respiratory
TDM
LFTs
phenytoin induces/inhibits which enzymes?
strong inducer
3A4, 1A2, 2C9, 2C19
patients on which AEDs should use non-hormonal contraceptives
phenytoin
topiramate
VPA
how should phenytoin be administered in patients with an NG tube
tube feeds should be held for 1-2 hours before and after
phenobarb dosing
50-100mg BID-TID
phenobarb is contraindicated in
hepatic imp, dyspnea, PMH sed/hypnotic addiction, IA adminsitration
warnings for phenobarbital
drug dependency
resp depression
SJS/TEN
tolerance and hangover effects
fetal harm
phenobarb DDI
strong inducer
do not use with estrogen-containing OCs
what can happen with phenytoin drug concentrations and metabolism with time
phenytoin metabolism can become saturated over time where a small inc in dose can cause a large inc in Cp
need to correct for albumin
common concerns with AEDs
bone loss, CNS dep, suicide risk, SJS/TEN
which AEDs are NOT safe in pregnancy and are considered teratogenic
phenytoin
oxcarbazepine
carbamazepine
phenobarbital
primidone
clonazepam
what supplementation should be given to patients who are on AEDs and are of child bearing potential / aer pregnant
folate, vitamin D, Ca
what supplementation should be given to all patients on AEDs
Ca and Vit D
what SE are children more susceptible to and which AEDs cause this
more susceptible to hypohidrosis from topiramate and zonisamide
limit sun exposure
what supplementation can be given with VPA
carnitine
what can be given to patients on lamotrigine and VPA if they develop alopecia
selenium and zinc
which AEDs should not be used with estrogen-containing OCs and are recommended to use with non-hormonal contraceptives instead
phenytoin
topiramate
VPA
phenobarbital
which AEDs can cause SJS/TEN
lamotrigine
levetiracetam
oxcarbazepine
carbamazepine
benzo MOA
potentiate GABA
VPA MOA
potentiates GABA
phenobarb MOA
potentiates GABA
levetiracetam (keppra) MOA
CA channel blocker and potentiates GABA
pregabalin/gabapentin MOA
Ca channel blocker
oxcarbazepine MOA
Na and Ca channel blocker
carbamazepine MOA
Ca channel blocker
lamotrigine MOA
Ca channel blocker
phenytoin/fosphenytoin MOA
Ca channel blocker
topiramate MOA
Ca channel blocker