Anticonvulsants

Question 1

Causes of Seizures

Answer 1

CNS injury, Birth trauma, genetic ion channel defects.

Question 2

Types of Epilepsy

Answer 2

Primary idiopathic, secondary

Question 3

Simple Partial Seizure

Answer 3

Minimal spread, no loss of consciousness, limited motor or sensory involvement.

Question 4

Complex Partial Seizure

Answer 4

Starts small and spreads, altered level of consciousness, strong emotional feelings, recover after 30-120 seconds.

Question 5

Absence Seizure

Answer 5

Sudden, short, most often in children, brief loss of consciousness.

Question 6

Tonic-Clonic

Answer 6

Loss of consciousness, 4 phases: aura, tonic, clonic, postictal.

Question 7

3 main MoAs for treating seizures

Answer 7

Block voltage gated Na+ channels, increase GABA effects, and inhibit T type voltage gated Ca2+

Question 8

General Side Effects

Answer 8

Sedation, Diplopia, Nystagmus, Ataxia, GI upset, Decreased effectiveness of oral contraceptives, teratogen (except phenobarbital)

Question 9

Phenytoin

Answer 9

Dose dependent elimination, Blocks and prolongs Na activation, enhances release of GABA, prevents seizure propagation.

Question 10

Phenytoin Clinical Uses

Answer 10

Tonic clonic, partial, and status epilepticus

Question 11

Phenytoin Side Effects

Answer 11

General side effects plus Hirsutism, gingival hyperplasia, osteomalacia, megaloblastic anemia, fetal hydantoin syndrome.

Question 12

Fosphenytoin

Answer 12

More suited for IV use.

Question 13

Carbamazepine

Answer 13

TCA like compound, Inhibits Na+ channels, well absorbed orally. Used for tonic-clinic, partial, trigeminal neuralgia, bipolar.

Question 14

Oxacarbazepine

Answer 14

Newer version with shorter half life but active metabolite has a longer half life and fewer drug interactions

Question 15

Carbamazepine Side Effects

Answer 15

CNS depression, osteomalacia, aplastic anemia, megaloblastic anemia, SIADH, teratogen.

Question 16

Phenobarbital

Answer 16

Enhances GABA-A receptor by prolonging its opening, Used for a lot of different seizure types but specifically neonatal seizures, status epilepticus, and pregnant women.

Question 17

Primidone

Answer 17

Metabolized to phenbarbital by the liver.

Question 18

Ethosuximide

Answer 18

Blocks T type calcium channels. Drug of choice for absence seizures.

Question 19

Valproic Acid

Answer 19

Inhibits Na, T type Ca channels and GABA transaminase. Can be used for several seizure types but commonly used for absence seizures. Teratogen and can cause hepatotoxicity syndrome.

Question 20

Diazepam and Lorazepam

Answer 20

Initial agents for status epilepticus. Diazepam has shorter duration. Can develop tolerance. Also used as a muscle relaxant.

Question 21

Gabapentin

Answer 21

GABA analog, blocks T type Calcium channels, used for tonic-clonic, parial, and neuropathic pain.

Question 22

Lamotrigine

Answer 22

Blocks Na and Ca channels, used for tonic-clonic, partial, and absence seizures. Can cause Stevens-Johnson Syndrome.

Question 23

Felbamate

Answer 23

Blocks Na channels and glutamate receptors. Adjunct for seizure state.

Question 24

Topiramate

Answer 24

Sedation, confusion, paresthesias, anorexia. AE with zonisamide..

Question 25

Tiagabine

Answer 25

Inhibits GABA reuptake, used in partial seizures. Causes sedation, dizziness, headache, and tremor.

Question 26

Baclofen

Answer 26

GABA-B receptor agonist, used as a muscle relaxant. Causes less sedation than Diazepam.