Chapter 71: Seizures/Epilepsy Flashcards
1
Q
What is the most common test used to diagnose epilepsy
A
EEG
2
Q
Key drugs that can lower the seizure threshold
A
Bupropion Clozapine Theophylline Varenicline Carbapenems (esp. imipenem) Lithium Meperidine Penicillin Quinolones Tramadol
3
Q
Where does a focal seizure start
A
One side of the brain, but can spread to the other side
4
Q
Where does a generalized seizure start
A
Both sides of the brain
5
Q
If a focal seizure results in no loss of consciousness, it is called
A
focal aware seizure
previously known as simple partial seizure
6
Q
If a focal seizure results in loss of consciousness, it is called
A
focal seizure with impaired awareness
previously complex partial seizure
7
Q
What are tonic symptoms
A
rigid or tense muscles
8
Q
Generalized seizures with non-motor symptoms are called
A
absence seizures
“staring spells”
9
Q
What is status epilepticus
A
A seizure that lasts beyond 5 minutes. It is a medical emergency
after 30 min, long-term damage occurs
10
Q
What are the 3 phases of status epilepticus called and what are the time intervals for them
A
0-5 minutes = stabilization phase
5-20 minutes = initial treatment phase
20-40 minutes = second treatment phase
11
Q
What should be done during the stabilization phase of SE
A
Time the seizure
Start EEG, oxygen may be needed
Check AED levels, electrolytes, if BG low - treat with D25-D50
12
Q
What should be done during the initial treatment phase of SE
A
If seizure continues:
Give IV lorazepam (Ativan)
Alternatives if IV unavailable: IM midazolam (Versed) or rectal diazepam (Diastat)
13
Q
What should be done during the second treatment phase (20-40 min) of SE
A
If seizure continues:
Give regular AED: IV fosphenytoin, valproic acid, levetiracetam (phenobarbital if others are unavailable)
14
Q
Diastat AcuDial packages contain two rectal syringes prefilled with diazepam rectal gel. What doses does it come in
A
2.5, 10 and 20 mg
15
Q
How do you use Diastat AcuDial
A
- Syringes must be dialed to the right dose and locked BEFORE DISPENSING
- Once locked, the green band should say “READY,” and the syringe cannot be unlocked
16
Q
CBD brand name for seiures
A
Epidiolex
17
Q
What kind of diet can be used in patients with refractory seizures
A
Ketogenic
18
Q
What is the ratio of fats : protein and carbs combined in a ketogenic diet
A
4:1
19
Q
What medication is used for absence seizures
A
ethosuximide
20
Q
What is the MOA of benzodiazepines as AED
A
Increases GABA
21
Q
What is the MOA of Valproic acid as AED
A
Increases GABA
22
Q
What is the MOA of ethosuximide as AED
A
T-type Ca channel blocker - slows down or stops transmission or the electrical signal
23
Q
What is the MOA of carbamazepine as AED
A
Na channel blocker - decr. neurons firing rate
24
Q
What is the MOA of phenytoin/fosphenytoin as AED
A
Na channel blocker - decr. neurons firing rate
25
Which neurotransmitters are responsible for causing a seizure
```
Deficiency in GABA (inhibitory NT)
Excess glutamate (excitatory)
```
26
Side effects of carbamazepine, oxcarbazepine, and eslicarbazepine
hyponatremia, rash, enzyme inducers
27
Side effects of gabapentin and pregabalin
Weight gain, peripheral edema, mild euphoria
28
Side effects of phenobarbital and primidone (prodrug of phenobarbital)
Sedation, dependence/tolerance/OD risk, enzyme inducers
29
Side effects of topiramate and zonisamide
Weight loss, metabolic acidosis
Nephrolithiasis and oligohydrosis/hyperthermia (in children)
30
All AEDs should be supplemented with
calcium and vitamin D
31
Women of childbearing age should supplement with ___ while on AEDs
folate
32
If taking valproic acid, what should you supplement with
possibly carnitine
33
If taking lamotrigine and valproic acid, what should you supplement with if alopecia develops
Supplement with selenium and zinc
34
Lamotrigine brand name
Lamictal
35
Lamotrigine dose for weeks 1 and 2
25 mg daily
36
Lamotrigine boxed warning
Serious skin reactions including SJS/TEN
37
Lamotrigine side effect
Alopecia (supplement selenium and zinc)
38
Lamictal starter kits are used to ensure correct dosing. Which color is the standard starting dose? When should you use it?
Orange
Use if no interacting medications
39
Lamictal starter kits are used to ensure correct dosing. Which color is a lower starting dose compared to the others? When should you use it?
Blue
Use if taking valproic acid (enzyme inhibitor)
40
Lamictal starter kits are used to ensure correct dosing. Which color is a higher starting dose compared to the others? When should you use it?
Green
Use if taking an enzyme inducer (e.g., carbamazepine, phenytoin, phenobarbital, primidone), and not taking valpoic acid
41
Lamotrigine drug interactions
Valproic acid increased lamotrigine concentrations more than two-fold. Use lower starting dose (blue box)
Inducers like carbamazepine, phenytoin, phenobarbital, & primidone decrease lamotrigine concentrations by 40%. Use the higher starting dose (green box)
42
Levetiracetam brand name
Keppra, Keppra XR
43
Keppra IV:PO ratio
1:1
44
Keppra warnings
psych reactions, including psychotic symptoms, somnolence, fatigue
45
T/F: Keppra does not have any significant drug interactions
True
46
Topiramate brand name
Topamax
47
Another use for topiramate
Migraine ppx
48
Topiramate warnings
Metabolic acidosis, oligohydrosis (reduced perspiration), nephrolithiasis (kidney stones), angle-closure glaucoma, hyperammonemia, fetal harm, visual problems
49
Topiramate side effects
Somnolence, difficulty with memory/concentration/attention, weight loss, anorexia
50
Topiramate monitoring
electrolytes (especially bicarbonate), intraocular pressure
51
Topiramate drug interaction
Can decrease OC effectiveness. Non-hormonal contraception is recommended
52
Depakene generic name
Valproic acid
53
Depakote, Depakote ER, Depakote Sprinkle generic name
Divalproex
54
Another use of divalproex
Bipolar and migraine ppx
55
Valproic acid therapeutic range
50-100 mcg/mL (total level)
| alb < 3.5 must adjust with formula (phenytoin formula)
56
Valproic acid boxed warning
hepatic failure, fetal harm (neural tube defects and low IQ scores)
57
Valproic acid warnings
Hyperammonemia (treat with **carnitine** in symptomatic adults only), thrombocytopenia (increased bleeding risk)
58
Valproic acid side effects
Alopecia (supplement selenium and zinc), weight gain
59
Valproic acid monitoring
LFTs (baseline and frequently in the first 6 months), platelets
60
What is the drug interaction between valproic acid and lamotrigine
risk of serious rash
| lower lamotrigine dose and titrate slowly
61
Tegretol generic name
Carbamazepine
62
Carbamazepine therapeutic range
4-12 mcg/mL
63
Carbamazepine boxed warnings
Serious skin reactions: patients of Asian descent should be tested for HLA-B*1502 allele prior to initiation
Aplastic anemia and agranulocytosis
64
Tegretol should be tested for ____ allele
HLA-B*1502
65
Carbamazepine contraindications
Myelosuppression
66
Carbamazepine warnings
hyponatremia (SIADH), fetal harm
67
Carbamazepine monitoring
CBC with diff and platelets, electrolytes (especially Na)
68
Carbamazepine drug interactions
Enzyme inducer, autoinducer - decreases levels of other drugs and itself
69
Which drugs can decrease levels of OCs and non-hormonal contraceptive is recommended
Topiramate, carbamazepine, oxcarbazepine, phenobarbital, primidone, phenytoin
| PS PORCS + topiramate + primidone
70
Vimpat generic name
Lacosamide
71
What class of drug is Lacosamide
C-V
72
Lacosamide warnings
Prolongs PR interval and increases risk of arrhythmias
73
lacosamide DDIs
caution with 2C19, 2C9, and 3A4 inhibitors (can increase lacosamide levels)
74
Trileptal generic name
Oxcarbazepine
75
Oxcarbazepine warnings
Increased risk of serious skin reactions: consider screening patients of Asian descent for **HLA-B*1502** prior to initiating therapy
Hyponatremia
76
Oxcarbazepine monitoring
Serum Na levels
77
Phenobarbital therapeutic range for adults
20-40 mcg/mL
78
Phenobarbital warnings
Habit forming, respiratory depression, fetal harm
79
Phenobarbital side effects
Physiological dependence, tolerance, hangover effect
80
Phenobarbital (and primidone) is a strong ____ of most enzymes
inducer
81
Dilantin generic name
Phenytoin
82
Cerebyx generic name
Fosphenytoin
83
Phenytoin IV:PO ratio
1:1
84
Phenytoin therapeutic range (total level and free level)
total level: 10-20 mcg/mL
free level: 1-2.5
| Ten Y Two in = in range of 10 - 20
85
Phenytoin IV administration rate should not exceed ___ mg/min & fosphenytoin IV should not exceed ___ mg PE/min. If given faster than these rates ____ and ____ can occur
Phenytoin - 50 mg/min
fosphenytoin - 150 mg PE /min
if faster risk of hypotension and cardiac arrhythmias
86
Phenytoin can cause extravasation, which leads to ____
Purple glove syndrome, characterized by edema, pain and bluish discoloration of the skin which can sometimes lead to tissue necrosis
87
Phenytoin should be avoided in patients with a positive ____
HLA-B*1502
Can also cause fetal harm
88
Phenytoin dose-related (toxicity) side effects
Nystagmus, ataxia, diplopia/blurred vision
89
Phenytoin chronic side effects
Gingival hyperplasia, hair growth, hepatotoxicity
| pheny to INCH - grows gingival hyperplasia, hair
90
Phenytoin monitoring
Serum phenytoin concentration, LFTs
IV: continuous cardiac and respiratory monitoring
91
Phenytoin and fosphenytoin are strong ____ of several enzymes
inducers
92
Phenytoin and fosphenytoin both have high ____
protein binding & can displace other highly protein-bound drugs or be displaced by other highly protein-bound drugs, causing an increase in levels that can lead to toxicity
93
Between Phenytoin and fosphenytoin, which has lower risk of purple glove syndrome
fosphenytoin
94
Between Phenytoin and fosphenytoin, which one requires a filter
Phenytoin
| remember GAL PLAT
95
Phenytoin must be diluted in ___, is stable for ___ hours, and should not be ____
NS (DIA**P**ACE)
4 hours
refrigerated (Dear **P**harmacist, Being Frigid Makes Me Edgy)
96
Tube feeds (increase/decrease) phenytoin absorption
decrease
Hold feedings 1-2 hours before and after administration
97
Zarontin generic name
ethosuximide
98
Ethosuximide warnings
Serious skin rash (SJS/TEN), blood dyscrasias
99
Felbamate boxed warnings
Hepatic failure, aplastic anemia
100
Fenfluramine boxed warning & warnings
boxed warning: valvulr heart disease, pHTN
warning: decr. appetite, weight loss
101
Gabapentin brand name
Neurontin
102
Pregabalin brand name
Lyrica
103
Pregabalin drug schedule
C-V
104
What is the prodrug of phenobarbital
Primidone
105
Vigabatrin boxed warning
Causes permanent vision loss (≥ 30% patients)
106
Zonisamide contraindication
Hypersensitivity to sulfonamides
107
Zonisamide side effects
Similar to topiramate, including oligohidrosis/hypertheramia and risk of nephrolithiasis
108
All AEDs cause:
CNS depression (e.g, dizziness, confusion, sedation, and ataxia/coordination difficulties)
109
Which AEDs are enzyme inducers
```
Carbamazepine
Oxcarbazepine
Phenytoin
Fosphenytoin
Phenobarbital
Primidone
```
| PS PORCS
110
Which AED(s) are enzyme inhibitors
Valproic acid (increases lamotrigine levels)
111
Which AED has the highest teratogenic risk
Valproic acid
112
The levels of all AEDs (increase/decrease) during pregnancy and may require a dose (increase/decrease)
Decrease
Increase
113
Which two AEDs can cause reduced or lack of sweating in young children
Topiramate and zonisamide
114
Which AEDs come in formulations that are easy to swallow for children
Lamotrigine (ODT, chewable tablets)
Levetiracetam (ODT, oral solution)
115
A child who remains seizure free for ____ can often be tapered off AEDs
1-2 years
116
Formula to adjust phenytoin dose
phenytoin correction = total phenytoin measured/ [(0.2 x albumin) + 0.1]
