Lecture 5: Antiepileptic Drugs Flashcards
Most anti-epileptic drugs block which types of channels?
Voltage-gated sodium channels and voltage-gated calcium channels.
How do some anti-epileptic drugs affect certain neurotransmitters?
Some enhance GABA-mediated inhibition and some inhibit glutamate-mediated excitation.
Where in a neuron are voltage-gated sodium channels expressed?
Throughout the neuronal membrane.
Do classical sodium channel blockers show preferential binding to open, closed or inactivated states of the channel?
Inactivated!
Do these classical sodium channel blockers affect high or low frequency firing?
High frequency firing - hence stopping seizures. The block is enabled by use (activation) and enhanced by frequency of use, meaning that high frequency action potential firing is reduced and low frequency firing is largely unaffected.
Which GABA receptor is responsible for fast inhibition, GABAa or GABAb?
GABAa.
Do anti-epileptic drugs that modulate GABA receptors bind competitively or allosterically?
Allosterically.
Which glutamate receptors are involved in fast excitatory synaptic transmission?
AMPA receptors.
How do anti-epileptic drugs that work on AMPA receptors work?
They are selective non-competitive antagonists which bind at the boundary between the extracellular and transmembrane domains, affecting conformation.
State some common adverse side effects of anti-epileptic drugs.
Somnolence, dizziness, fatigue, ataxia (unsteadiness) and headaches.
