Epilepsy Drugs

Question 1

What is the first line drug for absence seizures?

Answer 1

Ethosuximide

Blocks thalamic t type calcium channels

Side effects -EFGHIJ (ethosux causes … fatigue, gi, headache, itching, sJs

Question 2

What are the two first line treatments for tonic-clinic seizures?

Answer 2

Phenytoin - blocks Na channels (zero order kinetics, many side effects)

Valproic Acid - inc Na Chanel inactivation and inc GABA concentration by inhibiting GABA transaminase (neural tube defects)

Question 3

What is the first line treatment for focal seizures?

Answer 3

Carbamazepine

Blocks Na channels

Also used for trigeminal neuralgia

SJS , SIADH, blood dyscrasias, teratogenic

Question 4

Benzos v Barbiturates

Answer 4

Benzos - inc frequency of Cl channel opening at GABA A receptor

Those with short half life have higher chance addiction (ATOM - alprazolam, triazolam, oxazepam, midazolam)

Barbiturates- inc duration of Cl- channel opening at GABA A receptors

Barbiturates have inc risk respiratory, cardio and CBS depression

Question 5

Vigabatrin

Answer 5

Inc GABA by irreversible inhibition of transaminase

Focal seizures

Black box warning for permanent vision loss

Question 6

Gabapentin

Answer 6

Inhibits high voltage activated Ca channels - designed as GABA analog

Question 7

Topiramate

Answer 7

Blocks Na channels and inc GABA action

Question 8

Lamotrigine

Answer 8

Blocks voltage gated Na channels, inhibits release of glutamate

SJS

Question 9

Levetiracetam

Answer 9

Unknown mechanism

Question 10

Tiagabine

Answer 10

Inc GABA by inhibiting reuptake