Anti Convulsant Pharm Flashcards
Excitatory and Inhibitory Neurotransmitter
Excitatory: Glutamate
Inhibitory: GABA
Effects Na+ / K+ movement across the cell
Na+ entering the cell is excitatory (depolarization)
K+ leaving is inhibitory, hyperpolarization
Location of the Cortex
Periphery of the brain
Absent Seizures are a subcategory of? Hemisphere affected? Areas of brain involved?
Primary Generalized Seizure
Both hemispheres affected
Abnormal synchronization of the thalamus and cortex
Absent Seizure SX
pt looks normal but, they are unresponsive, difficult to detect
Absent Seizure EEG Pattern
spike and wave
Drugs that inhibit Na channels affect ___ seizures
focal and secondary generalized seizures NOT absent seizures
Drugs that Inhibit Na+ Channels
Valproic Acid Lamotrigine Lacosamide Phenytoin Carbamazepine
Phenytoin used for ___ seizures? MOA?
Focal and tonic clonic seizures, NOT absent seizures
Slows the rate of recovery of the Na+ channels back to resting state
Carbamazepine MOA? Drug interactions?
Induces the P450. Decreases the rate of recovery of Na+ channels like Phenytoin
Decreases phenytoin bioavailability
Alters plasma levels of oral contraceptives, antibiotics (cyclosporins)
Methadone and L-Dopa
Na Channel Resting Position
Closed, the linker molecule is off to the side
Cell is hyperpolarized
Na Channel Activated Position
Open, Na can enter cell
Cell depolarizes
Na Channel
Cell is depolarized, K+ channels are opening to hyperpolarize cell
Linker molecule blocks the channel
Role of T-type Ca++ channel blockers in Absent Seizures
Normal state: depolarized + inactive in awake state
Absent Seizure: the Ca++ channel gets hyperpolarized activates the channel, causing the spike and wave pattern
What category of seizures do T-type Ca++ Channel blockers work on?
Absent seizures
Three specific benzodiazepines used for focal and tonic-clonic seizures?
Diazepam, Lorazepam, Midazolam
How do drugs that block High voltage Ca++ channels work? Can not be used for?
Inhibit entry of Ca ions into the presynaptic neuron which prevents the release of neurotransmitter
Absent seizures
Vigabatrin MOA? 2 Indications?
GABA analog, irreversibly minds to GABA transaminase, thereby increasing GABA levels
Infantile spasms and refractory focal epilepsy
What population is pregabalin for? Why?
Hepatic impaired patients because the drug is metabolized by the kidneys
The type of seizure that Na+ channel inhibitors are not used for?
Absent Seizures
3 Indications for Valproic Acid
generalized
focal
absence seizures
Effect of phenytoin and carbamazepine on P450 enzymes
Both can induce the enzyme and alter the metabolism of various drugs: oral contraceptive, antibiotics, and levodopa
Carbamazepine Treats..
focal seizures
Drugs that inhibit Na+ channels are most effect on ___seizures?
Focal and secondary generalized NOT absent seizures
