Anticonvulsants Flashcards
Phenobarbital MOA
GABA-A agonist
Phenobarbital Therapeutic Uses
most widely used anticonvulsant - acute and maintenance
Phenobarbital Adverse Effects
sedation
polyphagia
PU/PD
panting
hepatoxicity
blood dyscrasia
alter thyroxine levels
Phenobarbital Metabolism
hepatic metabolism via CYP450 enzymes
Pentobarbital MOA
GABA-A agonist
Pentobarbital Therapeutic Uses
emergency treatment of acute seizures = short acting
Primidone MOA
GABA-A agonist
Primidone Therapeutic Use
refractory anticonvulsant if phenobarbital is not working
Primidone Adverse Effects
hepatic toxicity
Primidone Contraindications
DO NOT USE IN CATS
Diazepam MOA
GABA-A agonist
Diazepam Therapetuic Use
appetite stimulant for cats
anticonvulsant
(different dosages)
Diazepam Adverse Effects
hepatic toxicosis in cats
Is diazepam used for maintence of seizure disorders?
NO - tolerance and cross tolerance can develop
Clonazepam MOA
GABA-A agonist
Clonazepam Therapeutic Uses
anticonvulsant in cats - no hepatic damage
refractory treatment for dogs that do not respond to phenobarbital
Clonazepam Adverse Effects
withdrawal syndrome - taper off the dose
Clorazepate MOA
GABA-A agonist
Clorazepate Therapeutic Uses
refractory condition
safe for cats
WHat is Clorazepate metabolized into?
desmethyldiazepam - active metabolite of diazepam
Midazolam MOA
GABA-A agonist
Midazolam Therapeutic Use
acute anticonvulsant action
Potassium Bromide MOA
compete with Cl- transport at GABA receptors = hyperpolarization
stabilizes neuronal CMs
Potassium Bromide elimination/metabolism/half-life
glomerular filtration
tubular reabsorption
long elimination half-life
Potassium Bromide Therapeutic Use
add onto phenobarbital therapy (refractory seizures)
can be used alone if hepatic damage
Potassium Bromide adverse effects
weakness
depression
ataxia
bromism: coughing in cats
Potassium Bromide special considerations
diets high with Cl- influence bromide secretion
Zonisamide MOA
block Na and T-type Ca2+ channels - inhibits depolarization
stabilizes neuronal membrane
Zonisamide Adverse Effects
ataxia
vomiting
sedating
Zonisamide ADME
rapid and complete abdorption
wide distribution
partly excreted unchanged
partly undergoes glucuronidation
Levetiracetam MOA
modulates Ca2+ dependent NT release
binds SNARE protein 2A - prevents exocytosis
Levetiracetam Therapeutic Uses
preferred for patients with liver dx
more potent - used in refractory epilepsy
Drug combinations for Levetiracetam
phenobarbital/potassium bromide
Gabapentin MOA
binds a2-delta subunit of Ca2+v
reduces Ca2+ influx - inhibits exocytosis of NT
Gabapentin Therapeutic Uses
anticonvulsant
neuropathic path
Can Gabapentin cross the BBB?
requires amino acid transporter
Gabapentin half-life
short
Felbamate MOA
NMDA antagonist
potentiates GABA mediated neuronal inhibition
Felbamate therapeutic uses
local and generalized seizures
refractory seizures (last option bc expensive)
Carbamazepine MOA
inhibition of Navs
Carbamazepine therapeutic uses
treat neuropathic pain and manic-depressive illness
Carbamazepine ADME
slow absorption
long elimination half-life
hepatic metabolism