Neuro: Antiepileptic Drugs

Question 1

What neuronal imbalance causes seizures?

Answer 1

Glutamate/Aspartate overload= over-excitation

Need more GABA!

Question 2

What state do Na-channel blockers work in? Open or closed?

Answer 2

Only in the open and inactivation; so it is state and use dependence

Question 3

MOA of Lamotrigine

Answer 3

Prolong fast inactivation state of Na(v) ion channels

Question 4

MOA of carbamazepine

Answer 4

Prolong fast inactivation state of Na(v) ion channels

Question 5

MOA of penytoin

Answer 5

Prolong fast inactivation state of Na(v) ion channels

Question 6

MOA of topiramate***

Answer 6

1. Prolong fast inactivation state of Na(v) ion channels
2. AMPA antagonist
3. Activates GABAa receptor Cl channels on post-synaptic

Question 7

MOA of Valproic acid***

Answer 7

1. Prolong fast inactivation state of Na(v) ion channels
2. Activates glutamic acid decarboxylase
3. inhibits GABA transaminase and SSD

Question 8

MOA of lacosamide**

Answer 8

1. Prolong fast AND 2. slow inactivation state of Na(v) ion channels

different than other Na channel blockers

Question 9

MOA of PerAMPAnel

Answer 9

Blocks the AMPA receptor

so Glutamate cannot excite the post-synaptic neuron

Question 10

MOA of felbamate

Answer 10

NMDA receptor antagonist

so Glutamate cannot excite the post-synaptic neuron

Question 11

What channels cause absence seizures?

Answer 11

T-type Ca+ channels in the thalamus

Question 12

What wave types characterize absence seizures?

Answer 12

3-Hz spike and wave

-from T-type Ca channels

Question 13

MOA of Ethosuximide

Answer 13

Blocks T-type Ca+ channels in Thalamus in Absence!

Question 14

MOA of Zonisamide**

Answer 14

1. Blocks T-type Ca+ channels in Thalamus

2. prolongs slow inactivation state of Na(v) ion channels

Question 15

MOA of levetiracetam

Answer 15

inhibits synaptic vesicle 2A protein

-less Glutamate release

Question 16

MOA of Brivaracetam

Answer 16

inhibits synaptic vesicle 2A protein

-less Glutamate release

Question 17

MOA of Gabapentin**

Answer 17

1. Blocks α2δ subunit of T-type Ca channels

2. Activates glutamic acid decarboxylase

Question 18

MOA of Pregabalin**

Answer 18

1. Blocks α2δ subunit of T-type Ca channels

2. Activates glutamic acid decarboxylase

Question 19

MOA of ezogabine**

Answer 19

1. KCNQ K+ Channel blocker on both pre- and post-synaptic

2. Activates GABAa receptor Cl channels on post-synaptic neurons

Question 20

MOA of viGABATrin

Answer 20

Inhibits GABA transaminase

Question 21

MOA of tiagabine

Answer 21

Inhibits GAT-1 reuptake channel

Question 22

MOA of Benzodiazepines

Answer 22

Activates GABAa receptor Cl channels on post-synaptic neurons

Question 23

MOA of Barbiturates (phenobarbitol)

Answer 23

Activates GABAa receptor Cl channels on post-synaptic

Question 24

Suffix of all benzodiazapines

Answer 24

-azepam

Question 25

Which GABAa receptor agonists are GABA independent?

Answer 25

Barbiturates | -simply bind and increase duration of Cl channel opening

Question 26

Which Which GABAa receptor agonists are GABA dependent?

Answer 26

Benzodiazepine | -requires GABA in channel already and allows Cl to open more readily

Question 27

What is a broad risk of all AEDs?

Answer 27

Abrupt withdrawl can cause status epilepticus Suicidal behavior and ideation

Question 28

Which drug is removed via Zero-order pharmacokinetics

Answer 28

Phenytoin | -saturable!

Question 29

Which drugs are CYP450 and UGT conjugation inducers?

Answer 29

Phenytoin, carbamazepine, and phenobarbital

Question 30

What two seizure syndromes may cannabidiol treat?

Answer 30

Lennox-Gastaut syndrome and Dravet syndrome

Question 31

Adverse effects of Phenytoin (2)

Answer 31

Gingival hyperplasia Hypocalcemia/osteoporosis

Question 32

Adverse effects of carbamazepine

Answer 32

Agranulocytosis and aplastic anemia | -get CBC

Question 33

What is unique about cabamazepines metabolism?

Answer 33

It induces auto-induction of Cyp450=self metabolism after 14 days

Question 34

Why would you use oxcarbazepine instead of carbamazepine?

Answer 34

Does not generate the toxic epoxide that causes the aplastic anemia of carbamazepine

Question 35

Adverse effects of Phenobarbitol

Answer 35

CNS depressant

Question 36

Adverse effect of vigabatrin

Answer 36

Perminent concentric vision loss

Question 37

What drugs inhibit conjugation by UGT?

Answer 37

Valproate and lamotrigine | =build up of drugs

Question 38

What drugs are most affected use of CYP450 inducers (phenytoin, carbamazepine, and phenobarbital)?

Answer 38

Oral contraceptives Anticoagulants (warfarin) HIV Medications

Question 39

How are the newer drugs cleared from the body?

Answer 39

Renal clearance

Question 40

How do you initially treat status epilepticus? both first and second

Answer 40

1st IV: Lorazepam* -oral midzaolam if no IV 2nd: Levetiracetam*, fosphenytoin, or valproate