19.6 Epileptic Discharges Flashcards
What is Epilepsy?
uncontrolled, excessive synchronisation of CNS activity
Epileptic discharges caused by
- Too little inhibition (not enough GABA)
- Too much excitation (too much glutamate)
Two main mechanisms of anti-epileptic drugs
- Enhancement of GABA
- Inhibition of Na+ channels/glutamate release
Enhancement of GABA - via 3 mechanisms
- GABAa receptor potentiation
- Inhibit GABA metabolism
- Inhibit GABA uptake into neurons and glia
Drugs to manage status epilepticus (acute)
- Benzodiazepine
- Phenytoin
Drugs to manage chronic epilepsy
- Valproate
- Carbamazepine
- Lamotrigine
Phenytoin MOA
Use-dependent block of Na+ channels
Benzodiazepine MOA
Bind to modulatory site on GABA-a receptor to increase its affinity for GABA = increase chloride ion entry = reduce excitability
Valproate MOA
Increase activity of GABA by inhibiting GABA transaminase enzyme responsible for breakdown
Carbamazepine MOA
Na+ channel blocker
Lamotrigine MOA
Na+ channel blocker
T/F - Diazepam is used to treat epilepsy
True
T/F - Drugs which reduce 5-HT action are a main treatment for depression
False
T/F - Drugs which potentiate GABA action are used as anxiolytics
True
T/F - Carbamazepine can be used in the chronic treatment of epilepsy
True
