Antiepileptics Flashcards
What are the types of partial and generalized seizures?
Partial:
- Simple Partial: no loss of consciousness w/ abnomral activity of single limb/muscle group
- Complex Partial: loss of consciousness with motor dysfunction such as chewing movement, diarrhea, urination
- Partial with secondarily generalized tonic-clonic: a partial seizure that evolved into a tonic-clonic seizure with LOC
Generalized:
- Tonic-clonic: immediate loss of consciousness with or without convulsions
- Absence (petit mal): self limited LOC pts stares and has rapid eye blinking; EEG with 3Hz spike and wave appears abruptly
What are the other generalized seizures?
- Atonic
- Tonic
- Clonic
- Myoclonic
- Febrile
- Status Epilepticus
Drugs that block volatage-gated Na+ channels?
Principla MOA
- Phenytoin
- Carbamazepine
- Oxcarbazepine
- Lamotrigine
- Zonisamide
May also contribute to effects of:
- Phenobarbital
- Valproate
- Topiramate
Drugs that block T-type Ca2+ channels?
- Ethosuximide
- Valproate
Drugs that enhance GABAergic neurotransmission postynaptically and presynaptically?
Postsynaptically:
- Benzodiazepine, Barbiturates, Topiramate
Presynaptically:
- Tiagabine (inhibit reuptake), Vigabatrin (irreversible inhibition of GABA aminotransferase)
Drugs that reduce glutamatergic neurotransmission postsynaptically and presynaptically?
Postsynaptically:
- Phenobarbital and Topiramate
Presynaptically:
- Gabapentin and Pregabalin (voltage gated Ca2+ channels)
- Levetiracetam (binds synaptic vesicles glycoprotein 2A - SV2A)
What are the drugs used for partial and secondarily generalized tonic-clonic seizures?
- Carbamazepine
- Oxcarbazepine
- Levetiracetam
- Zonisamide
- Phenytoin
- Valproate
- Lamotrigine
- Topiramate
- Phenobarbital
Drugs used for tonic-clonic seziures?
- Carbamazepine
- Oxcarbazepine
- Valproate
- Lamtrogine
- Phenytoin
- Topiramate
Drugs used for absence seizures?
- Ethosuximide
- Valproate which is DOC if presence of tonic-clonic seizures emerge during therapy
Drugs used for myoclonic seizures?
- Valproate DOC
- Topiramate
- Levetiracetam (adjunctive therapy)
Drugs used for atonic seizures?
- often refractory to all available medication
- Valproate and Lamotrigine may be beneficial
Tx for febrile convulsions?
- Diazepam given IV or rectally
Tx of Status epilepticus?
- Initial therapy phase: Benzodiazepine (midazolam, lorazepam, or diazepam)
- Second therapy phase: IV Fosphenytoin, Valproic acid, or Levetiracetam
- Third therapy phase: retry phase 2 or can try anesthetic doses of thiopental, midazolam, pentobarbital or propofol
What is used for drug induced seizures in nonepileptic pts?
- Diazepam, Lorazepam, Phenobarbital
Which antiepileptic drugs induce and inhibit cytohrome P450?
Inducers:
- Carbamazepine
- Oxacarbazepine
- Phenobarbital
- Phenytoin
Inhibitors:
- Valproate
