Epilepsy/ Seizures Flashcards
Name the 2 basic grps that seizures are gen classified into.
Partial seizures
Generalized seizures
What’s epilepsy?
Unprovoked seizures or abnormal “electrical storms” in the brain
What’s a partial seizure? Diff btw simple partial and complex partial seizures?
Starts in 1 part of the brain where the pt is either conscious or unconscious.
Simple partial= if there’s NO loss of consciousness
Complex partial = if there’s loss of consciousness
Are partial seizures (PS) only confirmed to 1 part of the brain?
No!
PS can spread to the other hemisphere of the brain resulting in “secondarily generalized tonic-sonic seizures”
Note: simple and complex PS stays in the hemisphere where the seizures start
What’s generalized seizures (GS)?
GS begins in BOTH hemispheres of the brain where consciousness is impaired
What’s the difference btw Secondarily generalized tonic-clonic seizures and Generalized seizures
Secondarily generalized tonic-clonic seizures = starts in 1 hemisphere and spreads to another hemisphere
Generalized seizures = starts in both hemisphere at the same time
What’s a status epilepticus?
Seizures that last longer than 5 minutes
OR
> = 2 seizures btw which the pt doesn’t regain consciousness
Which type of seizure/epilepsy is a medical emergency?
Status Epilepticus
List anticonvulsants/antiepileptic drugs/AEDs that are category D?
Carbamazepine
Clonazepam
Phenobarbital/Primidone
Phenytoin/Fosphenytoin
Topiramate
Valproate
All others are pregnancy category C
Which AEDs is assigned cat. X? Why?
Valproate used in migraine prophylaxis
Which AEDs is thot to have the highest risk of fetal harm?
Valproate
Whats the most common types of SE AEDs users experience?
CNS SEs e.g. Dizziness, somnolence and cognitive dysfunction (not surprising as AEDs penetrate CNS to work)
Most AEDs are strong inducers/ inhibitors/ substrates?
Most AEDs are strong INDUCERS
List the main AEDs that are strong inducers
Carbamazepine
Oxcarbazepine
Fosphenytoin
Phenytoin
Phenobarbital
Primidone
Topiramate (>= 200mg/d)
Effects of strong inducers (most AEDs)?
They can lower the blood conc of many drugs, as they increase their metabolism, so the other drugs are removed quickly from the body
What supplement should all pts on enzyme-inducing AEDs be on? Why?
Vit. D and Calcium
Bcuz bone loss can occur as soon as 2 yrs after starting AEDs, making pts prone to osteoporosis
Do all AEDs require MedGuide?
Yes.
All AEDs require a MedGuide due to risk of suicidality
How should seizure meds be d/c?
Taper off med slowly
Never d/c seizure meds abruptly due to seizure risk
When do u call 911 if u witness seizure?
Time seizure with ur watch, if longer than 5 mins without signs of slowing down, or
if person has trouble breathing afterwards, or
Appears to be inured, in pain, or
Recovery is unusual in some way
How can u keep the airway of the person experiencing seizures clear?
Turn the person gently onto 1 side
What’s the tx of status epilepticus?
Rapid-acting BZD first e.g. Lorazepam (BZD of choice in status)
Followed by AED therapy (LD followed by MD)
List BZD used to treat Status Epilepticus. Which is drug of choice?
Lorazepam (Ativan) - drug of choic
Diazepam
Rectal diazepam (Diastat Acudial)
What’s the dose of lorazepam used in status epilepticus?
Lorazepam (Ativan): 4mg given by slow IV (adult)
Max rate - 2mg/min
May repeat in 5-10 minutes, if no response
What’s the 2nd line tx in status epilecticus?
AEDs
List 1st line tx in Partial, including secondarily generalized
Carbamazepine
Lamotrigine
Levetiracetam
Oxcarbazepine
List 1st line tx in Primarily Generalized Tonic-Clonic ONLY (type of partial seizure)
Lamotrigine
Levetiracetam
Valproate
List 1st line tx in Absence seizures
Ethosuximide
Valproate
List 1st line tx in Atypical Absence, Myoclonic, Atonic seizures
Ethosuximde
Lamotrigine
Levetiracetam
Valproate
List 1st gen AEDs
Benzodiazepines (BZD)
Carbamazepine (CBZ)
Ethosuximide
Phenobarbital/Primidone
Phenytoin/Fosphenytoin
Valproic acid/Valproate
MOA of BZD (1st generation AED)
BZDs enhance the activity of gamma-aminobutyric acid (GABA)
GABA is an inhibitory neurotransmitter
List agents under BZDs (1st generation AED)
Clonazepam (Klonopin)
Clobazam (Onfi)
SEs of BZDs (1st generation AED)
Drowsiness
Ataxia
Behavior disorder
Dizziness
Lethargy
Cognitive impairment (limit other CNS depressants)
Depression
Physiological dependence
Tolerance
Retrograde amnesia
Which BZD used as aces is pregnancy cat. C? D?
Preg cat. C = Clobazam (Onfi)
Preg cat. D = Clonazepam (Klonopin)
Is Clonazepam a major 3A4 inducer, inhibitor or substrate?
Clonazepam is a major 3A4 substrate
MOA of carbamazepine? (1st generation AED)
Fast Na channel blocker
Stimulates release of anti diuretic hormone (ADH) => reabsorption of water
What’s the brand name of Carbamazepine? (1st generation AED)
Tegretol; Tegretol XR
Carbatrol
Epitol - used for Bipolar
What’s the therapeutic range of CBZ (Tegretol, Tegretol XR, carbatrol) (1st generation AED)?
4-12 mcg/mL
What’s the black box warning of CBZ (Tegretol; XR, Carbatrol) (1st generation AED)?
Serious skin rxns, including SJS and TEN
Fatal blood cell abnormalities (including aplastic anemia and agranulocytosis)
What MUST be done b4 a pt of Asian descent use CBZ (Tegretol; XR, Carbatol) (1st generation AED)?
Must be tested for HLA-B*1502 allele PRIOR to therapy
If positive CBZ can’t be used
If a pt of Asian descent tests positive for HLA-B*1502, can they still use CBZ (Tegretol; XR, Carbatrol) (1st generation AED)?
No!
Unless benefit clearly outweighs the risk
What’s the warning associated with CBZ (Tegretol; XR, Carbatrol) (1st generation AED) use?
Serious skin rxns (onset usually 2-8 wks after initiation)
SEs of CBZ (Tegretol; XR, Carbatrol) (1st generation AED)?
Nausea
Vomiting
Dizziness
Drowsiness
Headache
Ataxia
Fatigue
Vit. D and Calcium deficiency (bone loss)
SIADH/hyponatremia
Hepatotoxicity
Is CBZ an inhibitor, substrate/ inducer?
Potent CYP 450 INDUCER and autoinducer of many enzymes (1A2, 2C19, 2C8/9, 3A4)
T4 LOWERS the level of many drugs and of itself
And a major 3A4 Substrate (t4 inh will increase its level)
What supplementation is req with the use of carbamazepine (Tegretol; XR, Carbatrol) (1st generation AED)?
Calcium and Vit. D
Generally, should OCPs be used concurrently with AEDs?
No!
Use alternative, nonhormonal contraceptive
What seizure type is CBZ (Tegretol; XR, Carbatrol) (1st gen AEDs) used for?
Partial (simple and complex), including secondarily generalized
MOA of Ethosuximide?
T-type Ca channel blocker that increase seizures threshold and suppresses paroxysmal spike-and-wave pattern in absence seizures
What’s the brand name of Ethosuximide (1st gen AEDs)?
Zarontin
SEs of Ethosuximide (1st gen AEDs)?
GI upset (weight loss, abdominal pain, nausea & vomiting)
Hiccups
Types of seizure Ethosuximide (1st gen AEDs) is used for?
Absence seizure
Atypical Absence, Myoclonic, Atonic seizures
Is Ethosuximide a substrate, inducer/ inhibitor?
Major 3A4 substrate
T4 strong inducers like CBZ, Fosphenytoin, phenytoin, phenobarbital, Primidone may LOWER Ethosuximide levels
Which AEDs may INCREASE the level of Ethosuximide (1st gen AEDs)? (Most other AEDs lowers it’s level)
Valproic acid
MOA of phenobarbital/Primidone? (1st gen AEDs)
Enhance gamma-aminobutyric acid (GABA)- mediated chloride influx
What’s the brand name of phenobarbital?
Luminal
What’s Primidone (Mysoline)?
Prodrug of phenobarbital and phenylethylmalonamide (PEMA)
What’s the therapeutic range of phenobarbital (Luminal) and Primidone (Mysoline) in adults? (1st gen AEDs)
20-40 mcg/mL