Epilepsy Drugs

Question 1

Epilepsy drugs that block/inactivate sodium channels

Answer 1

Phenytoin
Carbamazepine
Valproic Acid
Topiramate
Lamotrigine

Question 2

Blocks thalamic T-type Ca2+ channels.
DOC for absence seizures.
SE: constipation, urticaria, SJS.

Answer 2

Ethosuximide

Question 3

Potentiates GABAa by inc FREQUENCY of chloride channel openings; DOC acute status epileptics, second line for eclampsia seizures

Answer 3

Benzos

Question 4

DOC eclampsia seizures

Answer 4

MgSO4 (benzos are second line)

Question 5

Inactivates sodium channels.
Zero order kinetics.
SE: gingival hyperplasia, SLE, megaloblastic anemia, fetal hydantoin syndrome,
Induces P450!

Answer 5

Phenytoin

Question 6

Inactivates sodium channels.
DOC for partial seizures.
SE: Blood dyscrasias (agranulocytosis + aplastic anemia), SIADH, SJS

Answer 6

Carbamazepine

Question 7

Inactivates sodium channels and increases GABA by inhibiting GABA transaminase.
DOC: myoclonic seizures
SE: neural tube defects in fetus, hepatotoxic

Answer 7

Valproic acid

Question 8

Inactivates high-voltage-activated Ca+ channels. Designed as a GABA analog.
Also used for peripheral neuropathy, postherpetic neuralgia, migraine prophylaxis, bipolar disorder
SE: ataxia, sedation

Answer 8

Gabapentin

Question 9

Potentiates GABA(a) by inc DURATION of chloride channel openings.
CI in porphyria.
DOC infant epilepsy
SE: induces 450, cardioresp depression

Answer 9

Phenobarbital

Question 10

Blocks sodium channels and inc GABA action.
Also used for migraine prophylaxis.
SE: kidney stones, weight loss

Answer 10

Topiramate

Question 11

Blocks voltage-gated sodium channels. Used for epilepsy and bipolar maintenance.
SE: SJS (titrate slowly)

Answer 11

Lamotrigine