Antiseizure Drugs Flashcards
Phenytoin
Fosphenytoin
Mechanism of action
Block high-frequency firing of neurons through action on voltage-gated (VG) Na+ Channels, decreases synaptic release of glutamate
Cyclic ureides
Phenytoin
Fosphenytoin
Phenobarbital
Ethosuximide
Block high-frequency firing of neurons through action on voltage-gated (VG) Na+ Channels, decreases synaptic release of glutamate
Phenytoin (Cyclic ureide)
Fosphenytoin (Cyclic ureide)
Carbamazepine (Tricyclic)
Mechanism of action
Phenytoin
Fosphenytoin
Pharmacokinetics
Absorption is formulation dependent, highly bound to plasma proteins, no active metabolites, dose-dependent elimination, t 1/2 12-36 h, fosphenytoin is for IV, IM routes
Absorption is formulation dependent, highly bound to plasma proteins, no active metabolites, dose-dependent elimination, t 1/2 12-36 h, fosphenytoin is for IV, IM routes
Phenytoin
Fosphenytoin
Pharmacokinetics
Phenytoin, Fosphenytoin
Clinical applications
Generalized tonic-clonic seizures, partial seizures
Generalized tonic-clonic seizures, partial seizures
Phenytoin, Fosphenytoin (Cyclic ureides)
Carbamazepine, Oxcarbazepine (Tricyclics)
Clinical applications
Phenytoin
Fosphenytoin
Toxicities, Interactions
TOXICITY: Diplopia, ataxia, gingival hyperplasia, hirsutism, neuropathy, INTERACTIONS: Phenobarbital, carbamazepine, isoniazid, felbamate, oxcarbazepine, topiramate, fluoxetine, fluconazole, digoxin, quinidine, cyclosporine, steroids, oral contraceptives, other
TOXICITY: Diplopia, ataxia, gingival hyperplasia, hirsutism, neuropathy, INTERACTIONS: Phenobarbital, carbamazepine, isoniazid, felbamate, oxcarbazepine, topiramate, fluoxetine, fluconazole, digoxin, quinidine, cyclosporine, steroids, oral contraceptives, other
Phenytoin
Fosphenytoin
Toxicities, Interactions
Ethosuximide
Mechanism of action
Reduces low-threshold Ca2+ currents (T-type)
Reduces low-threshold Ca2+ currents (T-type)
Ethosuximide
Mechanism of action
Ethosuximide
Pharmacokinetics
Well absorbed orally, with peak levels in 3-7 h, not protein bound, completely metabolized to inactive compounds, t 1/2 typically 40 h
Well absorbed orally, with peak levels in 3-7 h, not protein bound, completely metabolized to inactive compounds, t 1/2 typically 40 h
Ethosuximide
Pharmacokinetics
Ethosuximide
Clinical applications
Absence seizures
Absence seizures
Ethosuximide
Clinical applications
Ethosuximide
Toxicities, Interactions
TOXICITY: Nausea, headache, dizziness, hyperactivity, INTERACTIONS: Valproate, phenobarbital, phenytoin, carbamazepine, rifampicin
TOXICITY: Nausea, headache, dizziness, hyperactivity, INTERACTIONS: Valproate, phenobarbital, phenytoin, carbamazepine, rifampicin
Ethosuximide
Toxicities, Interactions
Tricyclics
Carbamazepine
Oxcarbazepine
Eslicarbazepine acetate
Carbamazepine
Oxcarbazepine
Eslicarbazepine acetate
Tricyclics
Carbamazepine
Mechanism of action
Block high-frequency firing of neurons through action on voltage-gated (VG) Na+ Channels, decreases synaptic release of glutamate
Carbamazepine
Pharmacokinetics
Well absorbed orally, with peak levels 6-8 h, no significant protein binding, metabolized in part to active 10-11-epoxide, t 1/2 of parent ranges from 8 to 12 h in treated patiens to 36 h in normal subjects
Well absorbed orally, with peak levels 6-8 h, no significant protein binding, metabolized in part to active 10-11-epoxide, t 1/2 of parent ranges from 8 to 12 h in treated patiens to 36 h in normal subjects
Carbamazepine
Pharmacokinetics
Carbamazepine
Clinical applications
Generalized tonic-clonic seizures, partial seizures
Carbamazepine
Toxicities, Interactions
TOXICITY: Nausea, diplopia, ataxia, hyponatremia, headache, INTERACTIONS: Phenytoin, carbamazepine, valproate, fluoxetine, verapamil, macrolide antibiotics, isoniazid, propoxyphene, danazol, phenobarbital, primidone, many other
