AntiEpileptic Drugs- Pharm Flashcards
Neurotransmitter’s that cause excitation
glutamate, aspartate
Neurotransmitter’s that cause inhibition
GABA
Block voltage-gated Na+ channels MOA
the drug will only work when the activation gate of the Na channels are open
What states are the voltage-gated Na+ channels’ activation gate open
“open state” and “fast-inactivated state”
What are the names of the 6 drugs that are Voltage-gated Na+ channel blockers
Carbamazepine (Oxcarbazepine/Eslicarbazepine), Lamotrigine, Phenytoin (Fosphenytoin; IV form), Topiramate, Valproic acid/Divalproex (Valproate; IV form), Lacosamide (Zonisamide/Rufinamide)
Name of drug that enhances slow inactivation of Na channels
Lacosamide
Name of drugs that inhibits post-synaptic AMPA receptor
Topiramate & Perampanel
What ions come through either the AMPA receptor/NMDA receptor
Na+ and Ca+2
Name of drug that inhibits NMDA receptor
Felbamate
What NT binds to the AMPA/NMDA receptor to open it
glutamate
What type of channel is active and is the hallmark of petit-mal seizures
T-type Ca2+ channels
Name of drugs that blocks T-type Ca2+ channels (pre-synaptic)
Ethosuximide and Zonisamide
Name of Drugs that inhibit synaptic vesicle 2A (SV2A) protein
Levetiracetam and Brivaracetam
Name of drugs that block the a2d subunit of T-type Ca2+ channels
Gabapentin and Pregabalin
Name of drug that opens (stimulates) K+ channels (pre-/post-synaptic)
Ezogabine
Name of drug that inhibits the reuptake of GABA by GAT-1
Tiagabine
Name of drugs that inhibit the metabolization of GABA via GABA-T (GABA Transaminase)
Valproic acid and Vigabatrin
Name of drug that inhibits the metabolization of GABA via SSD (Succinic Semialdehyde Dehydrogenase)
Valproic acid
Drugs that stimulate the enzyme GAD (Glutamic acid decarboxylase) that converts glutamate to GABA
Valproic acid, Gabapentin, Pregabalin
How do post-synaptic GABAergic receptors work
GABA binds to the GABA receptor, this causes the Cl- channels to open; Cl- rushes into post-synaptic cell
List the names of the drugs that enhance post-synaptic GABA-ergic neuronal transmission
Barbiturates, Benzodiazapines, Topiramate
Which drug binds to an allosteric site, this potentiates GABA binding, and then causes the Cl- channels open with greater frequency
Benzodiazepines (BZD) (Clonazepam, Clobazam, Lorazepam, Diazepam)
Which drug binds to a distinct allosteric site and increases the duration of Cl- channel opening
Barbiturates (PB) (phenobarbital, primidone)
Which drug is GABA INdependent and therefore is extremely lethal in high doses
Barbiturates
Which drug has multiple MOAs? Look it up in the slides, slide 58
Topiramate
What is the main side-effect of Cannabidiol (Epidiolex)
Hepatocellular injury
obtain AST/ALT & Albumin levels, ESPECIALLY if given with Valproic acid
General Warnings of AEDs
Stopping drug leads to increased epilespsy
Suicidal behaviors and ideations
General facts about Phenytoin
Zero order
Inducer of CYP-450
Toxicity causes Gingival hyperplasia
General facts about Carbamazepine
Inducer of CYP-450 and autoinduction (self-metabolism)
Toxicities: Leukopenia/Neutropenia/Thrombocytopenia
Baseline CBC (WBC) to compare
Oxcarbazepine & S-Licarbazone is a less toxic analog
Less hematological AE’s and less potent inducer of CYP
General facts about Phenobarbital
Requires serum drug monitoring
Risk of coma/resp. Depression & fatality
Inducer of CYP
Toxicities: CNS depressant and hypocalcemia/Vit D deficit/Osteoporosis
General facts about Vigabatrin
Toxicities: Permanent, progressive, bilateral, concentric vision loss
D/C after 3 months if no effective response
REMS program req
Drugs that induce CYP-450
Carbamazepine
Phenytoin
Phenobarbital
AED’s can cause Drug Rxns, what are they?
Increase oral contraceptive clearance → risk of pregnancy
Increases clearance of anticoags (Warfarin) → arterial/venous thrombosis
Increase clearance of HIV meds → HIV replication
Which AEDs block UGT, preventing metabolism of other drugs
Valproic acid & Lamotrigine
Which AEDs induce UGT, which helps with drug metabolism of other drugs
Phenytoin, Carbamazepine & Phenobarbital
Newer AEDs are cleared by?
the kidneys, adjust medication dose if there is injury to the kidneys
What is the treatment algorithm if an adult comes into the hospital with a seizure?
Convulsive Status Epilepticus in Adults - Tx Algorithim
Initial therapy: Lorazepam IV
Alt. Initial therapy: Diazepam
If no IV access: Midazolam
Second IV: Fosphenytoin or Valproic acid or Levetiracetam or Phenytoin
