Antiepileptic drugs

Question 1

What triggers an action potential?

Answer 1

Opening of Na+ channels; depolarising the membrane

Question 2

What channel opens after the initial depolarisation of the membrane?

Answer 2

Opening of calcium channels; triggering the release of glutamate in the synaptic cleft

Question 3

What receptors will glutamate bind to on the post-synaptic cleft?

Answer 3

AMPA; permit entry of sodium

NMDA; open and permit entry of calcium ions

Question 4

What receptor will GABA bind to on excitatory neurones?

Answer 4

GABA-A

Question 5

What ion channel opens on the excitatory neuron when GABA binds?

Answer 5

Chloride (negative)

Question 6

Which antiepileptics antagonise the sodium channels of the presynaptic neurone?

Answer 6

Carbamazepine
Lamotrigine
Phenytoin
Topiramate
Sodium valproate

Question 7

Which antiepileptics antagonise the presynaptic calcium channels?

Answer 7

Lamotrigine

Topiramate

Question 8

Which antiepileptics antagonise the postsynaptic T type calcium channels?

Answer 8

Sodium valproate

Question 9

Mechanism of action of gabapentin and pregabalin?

Answer 9

Bind to alpha 2 delta 1 to block calcium entry into the presynaptic neurone

Question 10

Mode of action of levetiracetam?

Answer 10

Binds to SV2A which is a membrane protein on the vesicles that contain glutamate; and therefore prevents glutamate release into the synaptic cleft

Question 11

Which antiepileptic results in hyponatremia?

Answer 11

Carbamazepine

Question 12

Which antiepileptics can result in blurred vision?

Answer 12

Lamotrigine

Phenytoin (can also cause gingival hyperplasia and hirsutism)

Question 13

Side effects of sodium valproate?

Answer 13

Weight gain
Liver toxicity
TERATOGENIC