Antiepileptics (PD Week 2)

Question 1

What is an epileptic seizure

Answer 1

a sudden synchronous discharge of cerebral neurons causing signs or symptoms that may be apparent to either the patient or observer

Question 2

what are the 3 mechanisms of action of antiepileptics

Answer 2

1. enhance GABA action (inhibitory)
2. inhibit Na+ channels (reduce AP firing)
3. inhibit Ca2+ channels

Question 3

What do Benzodiazepines do to GABA transmission as antiepileptics

Answer 3

they potentiate GABA effects at GABAa receptor via positive allosteric modulation

Question 4

What does Vigabatin do to GABA transmission as an anti-epileptic

Answer 4

it irreversible inhibits GABA-T which prevents the inactivation of GABA

Question 5

What does Tiagabine do in terms of GABA transmission as an anti-epileptic

Answer 5

it inhibits GABA reuptake into the presynaptic neuron by blocking GAT-1

Question 6

What channel does Pregabalin and gabapentin inhibit

Answer 6

voltage gated Ca2+ channels - it inhibits the ability of glutamate release

Question 7

What channel does phenytoin, carbamazepine and lamotrigine inhibit

Answer 7

Na+ channels preventing excitatory action potential firing

Question 8

What channel does Retigabine act on

Answer 8

K+ channels - it causes hyperpolarization to inhibit glutamate release

Question 9

What does Perampanel do as an antiepileptic

Answer 9

it blocks AMPA receptors to prevent glutamate effects post-synaptically

Question 10

What does Levetiracetam do as an antiepileptic

Answer 10

it binds to SV2A to inhibit the release of glutamate and neuronal firing patterns associated with seizures