Antiepileptics/CNS stimulants/Antiparkisonian Flashcards
Term used to designate a group of chronic central nervous system (CNS) disordered characterized by the onset of sudden disturbances of sensory, motor, autonomic, or psychic origin
Epilepsy
Goal of epilepsy treatment
control seizures with minimal medication related adverse effects
Antiepileptics are dosed based on _____ function
renal
Antiepileptics that rely on renal excretion:
Gabapentin Pregabalin Levitiracetam Vigabatrin Zonisamide
Principle binding protein for anti epileptic drugs
Albumin
Highly protein bound antiepileptics
Phenylbutazone
Thyroxine
Salicylates
Antiepileptics that compete for protein binding sites of highly bound antiepileptic drugs, can displace the bound drug and lead to increase in the plasma concentration:
Phenytoin
Valproate
Carbamazepine
Enzyme-inducing anti epileptic drugs (7)
PPPCLOT Phenobarbital Phenytoin Primidone Carbamazepine Lamotrigine Oxycarbazepine Topiramate
Enzyme-inducing anti epileptics affect which cytochrome?
p450
Enzyme-inducing anti epileptics and oral contraceptives
anti epileptics render oral contraceptives ineffective, higher dose required
Enzyme-inducing anti-epileptics and induction drugs
Increased dose requirements of: thiopental propofol midazolam ipioids non-depolarizing neuromuscular blocking drug
Phenytoin is ___% protein bound
90%
Phenytoin goal plasma concentration and its metabolism is unique:
Control of seizures is usually obtained when plasma concentrations are 10-20 ug/ml
When plasma concentration <10, first order kinetics
When plasma concentrations >10, zero order kinetics (saturated and dose dependent)
PLASMA CONCENTRATION MONITORING
Only agent for which plasma concentration monitoring is recommended due to nonlinear saturation dose kinetics
Phenytoin
Na, Ca, Na+Ca, or GABA?
Phenytoin
Na+ Ca
Na, Ca, Na+Ca, or GABA?
Carbamazepine
Na+ Ca
Na, Ca, Na+Ca, or GABA?
Phenobarbital
Ca and GABA
Na, Ca, Na+Ca, or GABA?
Benzodiazepines
GABA
Na, Ca, Na+Ca, or GABA?
Ethosuximide
Ca Channel
Na, Ca, Na+Ca, or GABA?
Primidone
Na
Na, Ca, Na+Ca, or GABA?
Valproate
Na + Ca
Na, Ca, Na+Ca, or GABA?
Lamotrigine
Na + Ca
Na, Ca, Na+Ca, or GABA?
Zonisamide
Na + Ca
Gabapentin acts on what?
GABA
Phenobarbital class
barbiturates
Phenobarbital is a second line anti epileptic due to _____
cognitive and behavioral SE
Phenobarbital SE in adult
sedation
Phenobarbital SE in peds
hyperactivity
Phenobarbital drug interaction:
accelerates interactions with lipid soluble drugs
Phenobarbital prolongs ___ channel opening and limits the spread of seizure activity and increases seizure threshold
Cl
Drug of choice for Digitalis arrhythmias
Phenytoin
Goal plasma concentration of phenytoin
10 to 20 ug/ml
Adverse side effects phenytoin
nystagmus, diplopia, vertigo, ataxia, neurotoxic effects
Phenytoin induces lipid soluble drugs…
carbamazepine, valproid acid, ethosuximide, anticoagulants, corticosteroids
Phenytoin and NMB
need higher doses of non-depolarizers
Valproic acid (inhibits/induces) metabolism
inhibits
valproic acid and phenytoin
Valproic acid slows metabolism of phenytoin
valproic acid and phenobarbital
valproic acid causes phenobarbital plasma concentration to increase by 50%
first line treatment for status epilepticus
Diazepam