Antiepileptics Flashcards
Voltage-gated Na blockers (stabilizers of inactive state)?
Carbamazepine, Oxcarbamazepine, Phenytoin, Lamotrigine
Carbamazepine class?
Sodium channel blocker
Carbamazepine for?
Complex partial epilepsy (versus primary generalized), bipolar affective disorder, neuropathic pain
Carbamazeipine toxicity?
Sedation, ataxia, diplopia
Carbamazepine adverse reactions?
Rash (rarely, Stevens-Johnson), mild increase in LFTs, mild myelosuppression, contraceptive failure
Toxicity of carbamazepine is due to?
Epoxide metabolite
Pharmacologic considerations of carbamazepine?
Highly protein bound; Autoinduction & heteroinduction occur (so much so that increased dose is needed 1-2 weeks into treatment); Short half-life
`Phenytoin class?
Sodium channel blocker
Phenytoin for?
Tonic-Clonic seizures of Primary Generalized Epilepsy or Partial onset and Secondary Generalized Seizures. Effective for acute seizures.
Phenytoin is less effective for what seizures?
Absence, myoclonic, atonic
Phenytoin toxicity?
Dizziness, nystagmus, ataxia, incoordination
Phenytoin adverse reactions?
Mild hepatotoxicity, myelosuppression, gingival hyperplasia, rash, hersutism, Lupus-like reaction, contraceptive failure, & (with long term use) cerebellar degeneration, peripheral neuropathy, osteoporosis
IV infusion of Phenytoin limited by?
Hypotension
IV Phenytoin for?
Status epilepticus
Phenytoin half-life?
Longer, can be used for once daily dosing
Oxcarbazepine class?
Sodium channel blocker
Oxcarbazepine has the same…
efficacy & indications as Carbamazepine
How is oxcarbazepine better than carbamazepine?
Less protein bound, less autoinduction, fewer interactions, less toxic, longer half-life
Oxcarbazepine for?
Complex partial epilepsy (versus primary generalized), bipolar affective disorder, neuropathic pain
Oxcarbazepine toxicity?
Sedation, ataxia, diplopia
Oxcarbazepine adverse reactions?
Rash (rarely, Stevens-Johnson), mild increase in LFTs, mild myelosuppression, contraceptive failure
Lamotrigine class?
Sodium channel blocker
Lamotrigine for?
Primary Generalized, Partial Complex, Secondary Generalization, Absence. Also: Bipolar Affective, Neuropathic pain
Unique about Lamotrigine?
Indication for use in children
Lamotrigine is less effective and may exacerbate?
Myoclonic seizures
Lamotrigine toxicity?
Dizziness, sedation, ataxia, diplopia, can cause contraceptive failure (more so than others)
Lamotrigine adverse reactions?
Rash (rarely, Stevens-Johnson) – rash is dose related, and slow initial titration is important.
Lamotrigine pharmacological considerations?
Less protein bound, hepatic metabolism, hepatic enzyme inducer
Lamotrigine competes with excretion with?
Valproic acid
Synergistic action with Lamotrigine?
Valproate (Depakote)