Anticonvulsants Flashcards
What are the different types of seizures
General
Partial/focal
What is a general seizure
A seizure that begins simultaneously in both hemispheres
What are different types of general seizure
Tonic clonic
absent
myoclonic
What are types of partial/focal seizure
Simple/complex partial seizure
Temporal lobe epilepsy
What is a partial/focal seizure
A seizure that begins in a specific area and may spread
What happens to brain activity in seizures
Wave patterns become irregular or asynchronous due to neuronal overactivity
What happens in glutamate mediated neurotransmission leading to glutamate inhibition
- VGSC opens leading to membrane depolarisation
- VGKC opens leading to membrane repolarisation
- VGCC mediated Ca2+ influx, leading to glutamate vesicle exocytosis and the synapse vesicle associated protein allows vesicle attachment to the presynaptic membrane
- glutamate binds to post synaptic receptors eg NMDA
What does cabamazine do? What does this treat? how long is the half life?
It induces hepatic enzymes and is a VGSC antagonist that treats partial seizures and tonic clonic seizures.
It has a half life of 16-30 hours so it’s LONG
What does phenytoin do? What does this treat? How long is the half life
It is a VGSC antagonist and a class 1b channel blocker that treats most forms of epilepsy apart from absent seizures
It has a LONG halflife
What is a VGKC enhancer do and what is an example of one? How long is it’s half life
hyperpolarises cells by K+ channel opining eg retigabine - SHORT HALF LIFE
What does a VGCC blocker do and what is an example? How long are the half lives?
prevents exocytosis of glutamate vesicles eg ethosiximide that is a t type ca2+ channel antagonist (LONG HALF LIFE)
What drug treatment is given for absent seizures?
ethosiximide
t type ca2+ channel antagonist therefore preventing exocytosis of glutamate vesicles
What does gabapentin treat
Partial seizures as an alpha 2 delta subunit inhibitor that is used as a VGCC blocker therefore preventing exocytosis of glutamate vesicles
What are examples of drugs that are exocytosis and receptor modifiers of glutamate? How long are their half lives
Levetiracetam (HL SHORT)
Topiramate (HL LONG)
Perampanel (HL LONG)
What does levetiracetam do and what does this treat
SV2A inhibitor (of vesicle exocytosis) that treats focal seizures
What does topiramate treat and what does it do
It is a kainate R gluk5 subunit inhibitor that affects VGSCs and GABA receptors, treating most types of epilepsy
What does peramanel do? What does this treat
AMPA selective inhibitor that treats partial seizures as an adjuvant
What happens in GABa mediated neurotransmission that leads to GABA enhancement
- GABA released tonically (basally) and/or via neuronal stimulation
- GABA activates post synaptically inhibitory GABA A receptors
- GABA A receptors are Cl- channels that lead to membrane hyperpolarisation
- GABA taken up by GAT (GABA transporter)
- GABA is metabolised by GABA-T (GABA transaminase)
What is clonazepam and what does it treat, is half life long or short
A benzodiazepine that is a GABA receptor agonist that binds to the DBZ receptor protein of GABA R
Treats all forms of epilepsy
With a LONG half life
What is phenobarbital and what does it treat? Is the half life long or short
A barbituate that is a GABA receptor agonist that binds to BARB receptor protein of GABA R therefore treating most forms of epilepsy (bar absent) and acts as a sedative in adults. It has a LONG half life (60hrs!! usual long is 30hrs)
What drug is a GAT 1 inhibitor? What does this treat? HL?
Tiagabine
Treat partial seizures as adjuvant
SHORT 6hr HL
what drug is a GABA T inhibitor and what does this treat? HL?
Sodium valproate
Treat all forms of epilepsy
Half life is meh at 12 hrs
What drug is a GABA T irreversible inhibitor? What does this treat
Vigabatrin that treats infantile spasms and adjuvant for partial seizures
