Anti-Convulsants Flashcards
What drug used to treat epilepsy blocks voltage gated Na+ channels?
Lamotrigine
How does Lamotrigine work as an anti-convulsant drug
Blocks voltage gates Na+ channels which prevents Na+ influx and the depolarisation of glutamatergic neurones, and therefore reduces glutamate excitotoxicity
What is the drug target of lamotrigine?
Voltage gated Na+ Channels
What are the side effects of lamotrigine?
rash, drowsiness, suicidal thoughts (Steven-Johnson’s syndrome)
How are the skin reactions to lamotrigine mitigated?
Introducing it gradually
What are the four drugs used to treat Epilepsy?
Sodium Valproate
Levetiracetam
Diazepam
Lamotrigine
Describe the mechanism of action of sodium valproate?
Inhibition of GABA transaminase prevents the breakdown of GABA.
This increases GABA concentrations directly in the synapse presynaptically and also indirectly prolongs GABA in the synapse due to the fact that extraneuronal metabolism of GABA is slowed which also slows GABA removal from the synapse.
What is the drug target of Sodium Valproate?
GABA Transaminase
What are the side effects of sodium valproate?
Stomach pain, diarrhoea, drowsiness, hair loss, weight gain
describe the mechanism of action of diazepam?
Increases choride ion influx in response to GABA binding at the GABA A receptor. Increased chloride ion influx associated with hyperpolarisation of excitatory neurones.
What is the drug target of diazepam?
benzodiazepine site on the GABA A receptor
What are the side effects of diazepam?
Drowsiness, respiratory depression,
Why is diazepam not used long term for the suppression of seizures
due to the development of tolerance
What are some uncommon but serious side effects of diazepam?
Haemolytic anaemia and jaundice
Describe the mechanism of action of Levetirecam?
Inhibition of the synaptic vesicle protein SV2A. It inhibits this protein and prevents vesicle exocytosis. A reduction in glutamate secretion is reduces glutamate excitotoxicity - therefore less seizures
