Seizure Disorder Flashcards
What are the drug causes of Seizures?
-antidepressants (bupropion, SNRI, TCA)
-antipsychotics
-amphetamines
-theophylline
-illicit substances
-tramadol/tapentadol
-withdrawal from alcohol, anticonvulsants, benzos, baclofen
What are the seizure types?
-partial or focal seizures: abnormal electrical activity in one hemisphere
-generalized seizures: abnormal electrical activity in both hemispheres
Describe Simple Focal Onset Seizures
without dyscognitive features
-no loss of consciousness
-involuntary twitching or jerking in one extremity
-sweating, salivating, vomiting (autonomic symptoms)
-numbness, tingling, feeling of deja vu, visual disturbances, hallucinations, ringing/buzzing sounds
Describe Complex Focal Onset Seizures
with dyscognitive features
-loss of consciousness
-similar presentation to simple focal onset seizures, but may also not make sense while speaking, lip smacking, picking at clothes, staring off into space, extreme changes in behavior postictal state (post- seizure) common
Describe Absence Generalized Onset Seizures
-sudden interruption
-blank stare
-no aura (“warning”) or postictal state
-shorter than complex focal seizures (2-30 seconds)
-generally presents in children and adolescents
Describe Myoclonic Generalized Onset Seizures
-brief shock-like muscle contractions
-may be repetitive
-can be confined to small isolated muscle group or larger areas
Describe Clonic Generalized Onset Seizures
-bilateral, symmetrical, rhythmic jerk movements
-longer than myoclonic seizures
Describe Tonic Generalized Onset Seizures
-stiffness in the limbs
-bilateral increased tone
-seconds to a minute
Describe Tonic-Clonic Generalized Onset Seizures
-5 phase characterization: loss of consciousness, flexion, extension, tremor, clonic
-phase of tonic followed by clonic
-prodromal (“warning”) symptoms in some patients
Describe Atonic Generalized Onset Seizures
-sudden loss in muscle tone
-very brief
-often in patients with intellectual impairment
-protective hardware
-hallmark of Lennox-Gastaut
What is Lennox-Gastuat Syndrome?
-severe, refractory seizure disorder
-commonly identified in childhood
-includes a variety of seizure types
-often requires combination medication therapy
What are the symptoms of postictal?
-confusion
-frustration
-weakness
-fatigue
-memory loss/confusion
-embarrassment
-headache
-nausea
How is seizure type identified and diagnosed?
-history and clinical evaluation (pt may not be a reliable historian of details of their seizures)
-radiologic evaluation
-laboratory evaluation
-EEG (most useful DURING seizure)
What are the consequences of not treating seizures?
-uncontrolled seizures may impact quality of life, lead to development of new seizure types, altered response to anticonvulsants
-prolonged seizure activity may lead to neurological damage and could be life threatening
What are factors associated with successful pharmacological therapy withdrawal?
if the patient…
-single seizure type
-age of onset of seizure was age 2-35
-has been seizure free for 2 years+
-normal neurological exam, EEG, and IQ
-complete seizure control within 1 year of initiating treatment
-taper dose over 6 months (no more than 25% per 2 weeks)
What is the relapse rate of seizures once withdrawn from pharmacotherapy?
70%
What drugs are considered broad spectrum for seizures?
-lamotrigine
-levetiracetam
-topiramate
-valproic acid
-zonisamide
What is the Black Box Warning of Lamotrigine?
serious skin rash
What are the adverse effects of Lamotrigine?
ASEPTIC MENINGITIS
What are the drug interactions of Lamotrigine?
-oral contraceptives
-valproic acid
What are the advantages of Lamotrigine?
-multiple uses in seizure disorders (efficacy in focal onset and generalized)
-multiple dosage forms
-generally well tolerated
-use in bipolar disorder
-fewer cognitive effects in the elderly
What are the disadvantages of Lamotrigine?
-slow titration to avoid serious skin rash
-not for rapid control
What are the adverse effects of Levetiracetam?
mood changes
-irritability
-aggression/agitation
What are the drug interactions of Levetiracetam?
minimal
What are the monitoring parameters of Levetiracetam?
behavioral and renal function (dosing adjustment needed)
What are the advantages of using Levetiracetam?
-well tolerated
-no significant drug interactions
-can be loaded
What are the disadvantages of Levetiracetam?
behavioral problems can limit therapy in some patients
What are the adverse effects of Topiramate?
-word filling difficulty
-paresthesias
-psychomotor slowing
-nephrolithiasis
-oligohydrolysis
-metabolic acidosis
-weight loss
What are the drug interactions of Topiramate?
phenytoin and valproic acid
What is Topiramate place in therapy?
may be considered for comorbid conditions such as migraines (efficacy seen) or obesity (due to SE of weight loss)
What are the adverse effects of Valproic Acid?
-GI upset
-thrombocytopenia
-hepatotoxicity
-hyperammonemia
-pancreatitis
-alopecia
-PCOS
-weight gain
What are the drug interactions of Valproic Acid?
-lamotrigine
-carbapenems
-aspirin
What are the monitoring parameters of Valproic Acid?
CBC, LFT, levels 50-100
What is Valproic Acid place in therapy?
may be useful in comorbidities such as migraines and bipolar disorder
What are the adverse effects of Zonisamide?
-impaired concentration
-paresthesias
-nephrolithiasis
-oligohydrosis
-metabolic acidosis
-agitation/irritability
-skin rash (SJS)
What are the disadvantages of Zonisamide?
-cognitive impairment with rapid dose increase
-sulfa allergy cross reaction and renal stones
What is the Black Box Warning of Valproic Acid?
hepatoxicity, mitochondrial disease, fetal risk, pancreatitis
What are the adverse effects of Carbamazepine?
-diplopia
-dizziness
-unsteadiness
-lethargy
-nystagmus
-ataxia
-nausea
-leukopenia, anemia, and thrombocytopenia
-HYPOnatremia
-skin rash (SJS or TEN)
-decreased vitamin D and bone density
What are the drug interactions of Carbamazepine?
-CYP3A4 substrate
-CYP3A4 major inducer (autoinducer, induces its own metabolism)
What are the monitoring parameters of Carbamazepine?
-HLA-B *1502 allele
-renal
-CMP
-BMP
-levels (4-12)
What drug may worsen absence seizures?
carbamazepine
What is the advantage of Carbamazepine?
minimal cognitive impairment
What are the disadvantages of Carbamazepine?
-may worsen absence seizures
-may precipitate tonic clonic seizures in pt with other generalized seizures
-do not use in pregnancy, teratogenicity
-rash risk with fast titration
What is the Black Box Warning of Carbamazepine?
rash, aplastic anemia, agranulocytosis
What are the adverse effects of Oxcarbazepine?
-HYPOnatremia (SIADH)
-skin rash (SJS/TEN)
-dizziness
-diplopia
-nystagmus
-nausea
-ataxia/gait
-drowsiness
-tremor
-decreased bone density
Is hyponatremia (SIAHD) more common with Carbamazepine or Oxcarbazepine?
oxcarbazepine
What are the disadvantages of Oxcarbazepine?
-hyponatremia is more common
-can be used if no response to carbamazepine but if pt had rash with CBZ there is a 30% chance that they will experience rash with oxcarbazepine
What is the indication of Eslicarbazepine?
typically reserved for failure of other agents
What are the side effects of Eslicarbazepine?
-HYPOnatremia
-rash
What are the advantages of Eslicarbazepine?
-once daily dosing (prodrug)
-lower risk of hyponatremia (SIADH)
What are the adverse effects of Phenytoin?
-gingival hyperplasia
-hirsutism, acne
-neuropathy
-agranulocytosis
-skin thickening, coarsening of facial features (look older)
-purple glove syndrome
-CNS effects
-cognitive dysfunction
-bone health
What are the drug interactions of Phenytoin?
-CYP2C9 substrate and inducer
-CYP2C19 substrate and inducer
What is the Black Box Warning of Phenytoin?
cardiovascular risk with rapid infusion
What are the disadvantages of Phenytoin?
-narrow therapeutic window (levels 10-20)
-zero-order: increase in dose leads to increased proportional drug levels
What are the adverse effects of Phenobarbital?
-respiratory depression
-liver dysfunction
-paradoxical hyperactivity (more agitation/irritability)
-cognitive effects
What are the drug interactions of Phenobarbital?
CYP2C9 substrate and major inducer
What are the monitoring parameters of Phenobarbital?
-LFT
-CBC
-behavior
-renal
-levels (10-40)
Primidone is a prodrug that is activated to be ________.
phenobarbital
What are the adverse effects of Lacosamide?
-CNS/GI effects
-ECG PR prolongation
-liver enzyme elevation
What are the drug interactions of Lacosamide?
very minimal
What are the monitoring parameters of Lacosamide?
-ECG
-renal
-hepatic
What are the disadvantages of Lacosamide?
AV conduction abnormalities so contraindicated in pt with heart block
What are the adverse effects of Gabapentin?
-dizziness
-drowsiness
-GI effects
-peripheral edema
-weight gain
What are the drug interactions of Gabapentin?
very minimal
What are the disadvantages of Gabapentin?
-frequent dosing
-risk of withdrawal
What are the indications of Gabapentin?
considered second line for focal onset seizures but consider if comorbid neuropathic pain
What are the adverse effects of Pregabalin?
-peripheral edema
-weight gain
-CNS effects
What are the advantages of Pregabalin?
-longer acting than gabapentin
-multiple other uses
What is the Black Box Warning of Perampanel?
serious psychiatric and behavioral reactions
What are the adverse effects of Perampanel?
-paranoia
-euphoria
-aggression
What are the adverse effects of Tiagabine?
-impaired concentration
-weakness
-CNS effects
-GI effects
What are the disadvantages of Tiagabine?
-caution in absence seizures
-can worsen some seizures if refractory
What is the Black Box Warning of Vigabatrin?
permanent vision loss
What are the adverse effects of Vigabatrin?
-blindness
-weight gain/edema
-GI effects
-CNS effects
What is the use of Vigabatrin?
infantile spasms
What is the monitoring parameters of Vigabatrin?
eyes, has a REM program (SHARE)
What is the Black Box Warning of Clobazam?
risk of concomitant benzo + opioid use, abuse/misuse/addiction, dependance, withdrawal
What are the adverse effects of Clobazam?
-behavioral changes
-amnesia
-CNS effects
What are the drug interactions of Clobazam?
LOTS OF INTERACTIONS
-CYP2C19 substrate
-CYP3A4 substrate
-CYP2D6 substrate
-CYP3A4 inducer
What is the Black Box Warning of Clonazepam?
risk of concomitant benzo + opioid use, abuse/misuse/addiction, dependance, withdrawal
What are the contraindications of Clonazepam?
severe hepatic impairment
What is the Black Box Warning of Felbamate?
aplastic anemia, hepatic failure
What are the adverse effects of Felbamate?
-GI upset
-anorexia/weight loss
-CNS effects
What are the drug interactions of Felbamate?
CYP3A4 substrate/inducer/inhibitor
What are the monitoring parameters of Felbamate?
-LFT
-CBC
-hepatic
What drug is ONLY indicated for absence seizures?
ethosuximide
What drugs should be avoided in absence seizures?
-carbamazepine
-phenytoin
-vigabatrin
What drugs are frequently used for Atonic seizures?
these are not the only ones used
-clobazam
-felbamate
-rufinamide
What are the adverse effects of Rufinamide?
-shortens QTc
-rash
-CNS effects
-GI effects
What are the drug interactions of Rufinamide?
prone to interactions
-CYP2E1 inhibitor
-CYP3A4 inducer
What are the advantages of Rufinamide?
minimal effect on cognition
What anticonvulsants are highly protein bound?
carbamazepine, phenytoin, valproic acid
What are some considerations when prescribing the elderly anticonvulsants?
-reduced organ function (reduced clearance, metabolism, and hypoalbuminemia= caution using highly protein bound medications, phenytoin, valproate)
-sensitive to neurocognitive effects
-additional medications (interactions)
What drugs may cause sperm abnormalities in males?
carbamazepine, oxcarbazepine, and valproic acid
What anticonvulsant may cause testosterone levels to increase?
levetiracetam
What anticonvulsant may cause testosterone levels to decrease?
valproic acid
How does estrogen effect seizures?
proconvulsant effects
How does progesterone effect seizures?
anticonvulsant effect
What are Catamenial Seizures?
seizures before/during menses or during ovulation
How can Catamenial Seizures be treated?
-intermittent dose increase of benzos
-consider acetazolamide or cyclic natural progesterone
What anticonvulsants are NOT safe for pregnancy?
-valproic acid
-topiramate
-carbamazepine
-phenytoin
-phenobarbital
