Pharmacology of Anticonvulsants (Epilepsy) Flashcards
Lamotrigine Sodium valproate Diazepam Levetiracetam
What is lamotrigine used for?
- Lamotrigine is a phenyltriazine antiepileptic used to treat some types of epilepsy and bipolar I disorder
What is the primary drug target of lamotrigine?
- Voltage gated Na+ channels
What is the drug target type of lamotrigine?
- Ion channel antagonist
What is the location of action of lamotrigine?
- Glutamatergic neurones
What is the mechanism of action of lamotrigine?
- Blocks voltage gated Na+ channels
- No Na+ influx
- No depolarisation of glutamatergic neurones
- Decreased glutamate excitotoxicity
What are the main adverse effects of lamotrigine (4)?
-
Common:
- Rash
- Drowsiness
-
Less common:
- Steven-Johnson’s syndrome
- Suicidal thoughts
What is sodium valproate used for?
- Valproic acid is an anticonvulsant used to control complex partial seizures and both simple and complex absence seizures
What is the primary drug target of sodium valproate?
- GABA transaminase
What is the drug target type of sodium valproate?
- Enzyme antagonist
What is the mechanism of action of sodium valproate?
- Inhibition of GABA transaminase prevents breakdown of GABA
- Increase in concentration of GABA in presynaptic synapse
- Prolongs GABA in the synapse (extraneuronal metabolism of GABA is slowed) & slows GABA removal from the synapse (opens Cl- channels)
- Increase in Cl- influx
What is the location of action of sodium valproate?
- Cells of the CNS
What are the main adverse effects of sodium valproate (8)?
-
Common:
- Stomach pain
- Diarrhoea
- Drowsiness
- Weight gain
- Hair loss
-
Less common:
- Hepatotoxicity
- Teratogenicity
- Pancreatitis
What is diazepam used for?
- Diazepam is a long-acting benzodiazepine with rapid onset commonly used to treat panic disorders, severe anxiety, alcohol withdrawal, and seizures
What is the primary drug target of diazepam?
- Benzodiazepine site on the GABA A receptor
What is the mechanism of action of diazepam?
- Binding to GABA A receptor
- Increase in Cl- influx
- Hyperpolarisation of excitatory neurones