Anticonvulsants Flashcards
What are the four mechanisms of Anticonvulsants?
- Enhance sodium channel inhibition
- Inhibit calcium channels
- Enhance GABA inhibition
- Inhibit glutamate receptors
Which drugs inhibit sodium channels?
Phenytoin, carbamazepine and lamotrigine
Which drugs inhibit calcium channels?
Ethosuximide, valproic acid, gabapentin, pregabalin
Which drugs enhance GABA ?
Benzodiazepines, barbiturates
What is the MOA of Phenytoin?
Prolongs the inactivation state of voltage gated sodium channels.
What are 2 pharmacokinectic properties of phenytoin?
- Induces CYP3A4
2. 90% bound to albumin
What are the side effects of phenytoin?
- Fatigue
- Dizziness
- Diplopia
- Cognitive impairment
What is the MOA for Carbamazepine?
- Blocks reactivation of voltage gated sodium channels.
2. Blocks NE reuptake
What are the side effects of carbamazepine?
- Dizziness
- Ataxia
- Nystagmus
Which drugs side effect can cause Steven-Johnson syndrome?
Lamotrigine
What are the MOAs of Valproate?
- Inhibits voltage gated sodium channels
- Inhibits T-type calcium channels
- May increase GABA synthesis and decrease degradation.
What are the side effects of Valproate?
- Tremor
- Hair loss
- Thrombocytopenia
What is the MOA of Ethosuximide?
Inhibits T-type calcium channels in thalamic neurons.
What population is Ethosuximide used for?
Absence seizures in children
What is the MOA of Zonisamide?
Inhibits T-type Calcium channels and prolongs the inactivation of sodium channels.