Sodium channel blockers
How does blocking sodium channels stop seizures?
Stabilize inactive sodium channels, reducing neuronal excitability and preventing repetitive firing
How do these drugs work?
Inhibit T-type calcium channels in neurons, reducing calcium influx
Is GABA an excitatory or inhibitory neurotransmitter?
Inhibitory
Carbamazepine is the most widely used anti-epileptic drug, it can be used for all types of seizures except for??
Absence (seizure in children where they become unaware of surrounds/don't respond for 10-30s)
Ethosuximide blocks calcium channels in the thalamus. What type of seizure are they used to treat?
Absence seizures
GABA transporters sit at the end of the prseynaptic neuron, transporting GABA from the cleft back to the presynaptic neuron.
Tiagabine is a GABA transporter inhibitor (GAT) - why would that reduce likelihood of seziures?
Greater concentration of GABA in synaptic cleft for extended time tobind to GABA receptors on post-synaptic cell
What enzyme do phenytoin and carbamazepine induce?
CYP450
Gabapentin and Pregabalin are not often used to treat seizures but something else??
Neuropathic pain
How do barbituates like phenobarbitol work?
Increases the amount of time that GABA (A) channels on the post-synpatic neuron are open, so more flood in --> more Cl- into the post synaptic neuron
What is the name of the sodium channel blocker that does not have an effect on CYP450 metabolism?
Lamotrigine
(so fewer drug interactions)
These two drugs bind the alpha-2-delta subunit of voltage-gated Ca²⁺ channels. What are they called?
Gabapentin and Pregabalin
Sodium valporate is often given to treat:
1. which type of seizure?
2. what age group
1. tonic-clonic
2. over 55s (teratogenic)