Anticonvulsants Flashcards
Epilepsy
disorder of brain function characterized by periodic and unpredictable seizures
Seizure
alteration of behaviors due to excessive firing of brain neurons
Partial/ Focal Seizure
neuron firing is localized to cerebral cortex
normally just one hemisphere
Generalized Seizure
widespread neuron firing
both hemispheres
Difference between Simple and Complex Partial Seizures
simple- consciousness preserved
complex- impaired consciousness
Tonic- Clonic Seizures
tonic phase- loss of consciousness, muscle rigidity, respiratory arrest
clonic phase- muscle jerking, lip/ tongue biting, urinary/ fecal incontinence
Absence Seizures
sudden onset and abrupt ending
impaired consciousness
stop around age 20
Myoclonic Seizures
single or multiple myoclonic muscle jerks
no loss of consciousness
can happen many times in a day
Pathophysiology of Epilepsy
hyperexcitable neurons fire abnormally and inhibitory (GABAa) synaptic currents break down to cause seizures
Examples of Na Channel Modulators that enhance fast action
phenytoin
carbamazepine
valproate
MOA of Na Channel Modulators that enhance fast inactivation
decrease Na influx, prolongs inactive state of neurons
Phenytoin
IV only
1st order, 2nd at high doses
increases metabolism of other drugs- bad mix w/ contraceptives
SE of Phenytoin
gingival hyperplasia
decreased bone density from increased Vit D metabolism
coarsening facial features
Active Metabolite of Carbamazepine
10, 11 epoxide
SE of Carbamazepine
blurred vision
stupor, coma, respiratory depression