Anticonvuslants 1.4 Flashcards
Topiramate (Topamax)*: Mechanisms of action
• 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)
Topiramate (Topamax)*: Uses
• 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
Topiramate (Topamax)*: Side Effects
• 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
Tiagabin *: Mechanism of Action
• GABA reuptake inhibitor
Tiagabin)*: Uses
• Adjunctive therapy in partial seizures
– >12 years of age
Tiagabin )*: Side Effects
• CNS depression-fatigue, dizziness, ataxia, decreased
cognition
• GI (abdominal pain, nausea, vomiting, diarrhea)
• Stevens Johnson rash
Levetiracetam (Keppra)**: Mechanism of Action
• Unknown, No appreciable metabolism
Levetiracetam (Keppra)**: Uses
• 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
Levetiracetam (Keppra)**: Side Effects
• CNS: somnolence, dizziness, headache
Oxcarbazepine (Trileptal)*: Mechanism of Action
• Blocks voltage dependent Na+ channels resulting in
stabilization of hyperexcited neural membranes
Oxcarbazepine (Trileptal)*: Uses
- Monotherapy or adjunct therapy for partial seizures
* Effective for medication resistant epilepsy
Oxcarbazepine (Trileptal)*: Pharmacokinetics/Chemistry
• Metabolized to active 10-hydroxycarbamazepine
metabolite
• Does not undergo autoinduction
Oxcarbazepine (Trileptal)*: Side Effects
• CNS: Headache, dizziness, somnolence, ataxia,
nystagmus
• GI: nausea, vomiting, abdominal pain
• Hyponatremia common in first 3 months
Pregabalin (Lyrica): Mechanism of Action
- Modulates calcium and glutamate flux
* Structural similarity to gabapentin
Pregabalin (Lyrica): Uses
- Adjunctive treatment of partial onset seizures
- Neuropathic pain
- Diabetic peripheral neuropathy
Zonisamide (Zonegran): Mechanism of Action
• May block Na+ channels and reduce T-type Ca2+
currents resulting in stabilization of neuronal
membranes
Zonisamide (Zonegran): Uses
• Adjunct therapy for partial seizures (patients 16
y.o. and older)
Zonisamide (Zonegran): Side Effects
• 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
Vigabatrin (Sabril): Mechanism of Action
• increase GABA by inhibition of GABA
Transaminase
Vigabatrin (Sabril): Uses
- Partial Seizures
* Refractory patients
Vigabatrin (Sabril): Side Effects
• Drowsiness, dizziness, weight gain, confusion
Antiepileptic medication and seizure types
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
