Anti-Convulsants - Core Drugs Flashcards
List examples of anti-convulsants.
lamotrigine
sodium valproate
diazepam
levitiracetam
What is the mechanism of action of lamotrigine?
Blocks voltage gated Na+ channels > prevents depolarisation of glutamatergic neurones > reduces glutamate excitotoxicity
What is the drug target of lamotrigine?
voltage gated Na+ channels
What are the side effects of lamotrigine?
rash, drowsiness
Steven-Johnson’s syndrome, suicidal thoughts
What is the mechanism of action of sodium valproate?
Inhibition of GABA transaminase > prevents breakdown of GABA > ^GABA concentrations directly > indirectly prolongs GABA in the synapse due to the fact that extraneuronal metanolism of GABA is slowed > 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 and diarrhoea, drowsiness, weight gain, hair loss
hepatotoxicity, teratogenicity,
pancreatitis
What is 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 (if i.v. or at high dose)
Haemolytic anaemia, jaundice
What is the main reason that diazepam is not used for long term suppression of seizures?
development of tolerance
What is the drug target of levetiracetam?
synaptic vesicle protein SV2A
Outline the mechanism of action of levetiracetam.
Inhibition of synaptic vesicle protein SV2A > prevents vesicle exocytosis > reduces glutamate secretion
What are common side effects of levetiracetam?
dizziness, somnolence, fatigue and headache
What feature of sodium valproate makes it increase serum concentration of many co administered drugs?
broad CYP enzyme inhibitor (CYP help drug breakdown)
