Anticonvuslants 1.4

Question 1

Topiramate (Topamax)*: Mechanisms of action

Answer 1

• Inhibits voltage-dependent sodium channels of
presynaptic membrane
• Potentiates the action of GABA by binding to a novel
modulatory site on the GABAA receptor
• Blocks excitatory amino acid receptors (kainate/AMPA)

Question 2

Topiramate (Topamax)*: Uses

Answer 2

• Adjunctive therapy in partial seizures
• Adjunctive therapy in primary generalized seizures
• Lennox-Gastaut syndrome in patients > 2 years of age
• Good monotherapy in patients with refractory Partial and
Tonic / Clonic generalized
• Migraine

Question 3

Topiramate (Topamax)*: Side Effects

Answer 3

• Somnolence and fatigue, dizziness, ataxia, decreased
cognition, nystagmus
• Renal stone formation in 1.5% of patients: Very important for boards
– Don’t use if history of kidney stones
• Hypersensitivity
• Weight loss
• Paresthesias (carbonic anhydrase inhibitor)
• GI (dyspepsia, constipation, nausea, vomiting,
abdominal pain)
Dr. Ferguson indicated very
important for various boards
Can be used in treatment of IICH

Question 4

Tiagabin *: Mechanism of Action

Answer 4

• GABA reuptake inhibitor

Question 5

Tiagabin)*: Uses

Answer 5

• Adjunctive therapy in partial seizures

– >12 years of age

Question 6

Tiagabin )*: Side Effects

Answer 6

• CNS depression-fatigue, dizziness, ataxia, decreased
cognition
• GI (abdominal pain, nausea, vomiting, diarrhea)
• Stevens Johnson rash

Question 7

Levetiracetam (Keppra)**: Mechanism of Action

Answer 7

• Unknown, No appreciable metabolism

Question 8

Levetiracetam (Keppra)**: Uses

Answer 8

• Adjunct therapy for partial seizures
• Becoming more popular in other seizures
• Useful in patients with medical illnesses involving the liver
and on hepatically metabolized drugs with potentially
serious side effects (e.g., coumarin, cyclophosphamide)
• Migraine

Question 9

Levetiracetam (Keppra)**: Side Effects

Answer 9

• CNS: somnolence, dizziness, headache

Question 10

Oxcarbazepine (Trileptal)*: Mechanism of Action

Answer 10

• Blocks voltage dependent Na+ channels resulting in

stabilization of hyperexcited neural membranes

Question 11

Oxcarbazepine (Trileptal)*: Uses

Answer 11

• Monotherapy or adjunct therapy for partial seizures

* Effective for medication resistant epilepsy

Question 12

Oxcarbazepine (Trileptal)*: Pharmacokinetics/Chemistry

Answer 12

• Metabolized to active 10-hydroxycarbamazepine
metabolite
• Does not undergo autoinduction

Question 13

Oxcarbazepine (Trileptal)*: Side Effects

Answer 13

• CNS: Headache, dizziness, somnolence, ataxia,
nystagmus
• GI: nausea, vomiting, abdominal pain
• Hyponatremia common in first 3 months

Question 14

Pregabalin (Lyrica): Mechanism of Action

Answer 14

• Modulates calcium and glutamate flux

* Structural similarity to gabapentin

Question 15

Pregabalin (Lyrica): Uses

Answer 15

• Adjunctive treatment of partial onset seizures
• Neuropathic pain
• Diabetic peripheral neuropathy

Question 16

Zonisamide (Zonegran): Mechanism of Action

Answer 16

• May block Na+ channels and reduce T-type Ca2+
currents resulting in stabilization of neuronal
membranes

Question 17

Zonisamide (Zonegran): Uses

Answer 17

• Adjunct therapy for partial seizures (patients 16

y.o. and older)

Question 18

Zonisamide (Zonegran): Side Effects

Answer 18

• CNS: dizziness, somnolence, headache, ataxia
• Anorexia; appetite loss
• Skin reactions – Stevens Johnson syndrome
• Fulminant hepatic necrosis
• Kidney stones
• Agranulocytosis, aplastic anemia
• cognitive side effects: psychomotor slowing,
difficulty with concentration, psychosis, mania,
depression

Question 19

Vigabatrin (Sabril): Mechanism of Action

Answer 19

• increase GABA by inhibition of GABA

Transaminase

Question 20

Vigabatrin (Sabril): Uses

Answer 20

• Partial Seizures

* Refractory patients

Question 21

Vigabatrin (Sabril): Side Effects

Answer 21

• Drowsiness, dizziness, weight gain, confusion

Question 22

Antiepileptic medication and seizure types

Answer 22

Broad spectrum: All seizure types (generalized from onset and partial onset seizures): Lamotrigine, levetiracetam, valproate, topiramate

Narrow spectrum: (SImple partial, complex partial, and secondarily generalized seizers: Carbamazepine, oxcarbazepine, phenobarbital, phenytoin

Absence seizure: Ethosuximide

Also the use of Benzodiazepines