Pharmacology of Anticonvulsants (Epilepsy) Flashcards

Lamotrigine Sodium valproate Diazepam Levetiracetam

1
Q

What is lamotrigine used for?

A
  • Lamotrigine is a phenyltriazine antiepileptic used to treat some types of epilepsy and bipolar I disorder
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2
Q

What is the primary drug target of lamotrigine?

A
  • Voltage gated Na+ channels
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3
Q

What is the drug target type of lamotrigine?

A
  • Ion channel antagonist
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4
Q

What is the location of action of lamotrigine?

A
  • Glutamatergic neurones
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5
Q

What is the mechanism of action of lamotrigine?

A
  • Blocks voltage gated Na+ channels
  • No Na+ influx
  • No depolarisation of glutamatergic neurones
  • Decreased glutamate excitotoxicity
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7
Q

What are the main adverse effects of lamotrigine (4)?

A
  • Common:
    • Rash
    • Drowsiness
  • Less common:
    • Steven-Johnson’s syndrome
    • Suicidal thoughts
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8
Q

What is sodium valproate used for?

A
  • Valproic acid is an anticonvulsant used to control complex partial seizures and both simple and complex absence seizures
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9
Q

What is the primary drug target of sodium valproate?

A
  • GABA transaminase
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10
Q

What is the drug target type of sodium valproate?

A
  • Enzyme antagonist
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11
Q

What is the mechanism of action of sodium valproate?

A
  • 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
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12
Q

What is the location of action of sodium valproate?

A
  • Cells of the CNS
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14
Q

What are the main adverse effects of sodium valproate (8)?

A
  • Common:
    • Stomach pain
    • Diarrhoea
    • Drowsiness
    • Weight gain
    • Hair loss
  • Less common:
    • Hepatotoxicity
    • Teratogenicity
    • Pancreatitis
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15
Q

What is diazepam used for?

A
  • Diazepam is a long-acting benzodiazepine with rapid onset commonly used to treat panic disorders, severe anxiety, alcohol withdrawal, and seizures
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16
Q

What is the primary drug target of diazepam?

A
  • Benzodiazepine site on the GABA A receptor
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17
Q

What is the mechanism of action of diazepam?

A
  • Binding to GABA A receptor
  • Increase in Cl- influx
  • Hyperpolarisation of excitatory neurones
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18
Q

What is the drug target type of diazepam?

A
  • Receptor agonist
19
Q

What is the location of action of diazepam?

A
  • Cells of the CNS
21
Q

What are the main adverse effects of diazepam (4)?

A
  • Common:
    • Drowsiness
    • Respiratory depression
  • Less common:
    • Haemolytic anaemia
    • Jaundice
22
Q

What are the 2 problems associated with diazepam?

A
  • Tolerance: Main reason that diazepam is not used for long term treatment is due to development of tolerance
  • Dependency: Diazepam is a schedule 4 controlled drug - addiction prone individuals are more likely to become dependent on diazepam
23
Q

What is levetiracetam used for?

A
  • Levetiracetam is a novel anticonvulsant agent used as an adjunct medication to manage partial onset, myoclonic, and generalized tonic-clonic seizures in patients with epilepsy
24
Q

What is the mechanism of action of levetiracetam?

A
  • Inhibition of SV2A
  • Prevents vesicle exocytosis
  • Decreased glutamate secretion
  • Decrease glutamate excitotoxicity
  • Decreased Na+ channels
  • Decreased Na+ deflux
25
Q

What is the primary drug target of levetiracetam?

A
  • Synaptic vesicle protein (SV2A)
26
Q

What is the drug target type of levetiracetam?

A
  • Enzyme antagonist
27
Q

What is the location of action of levetiracetam?

A
  • Neurones
29
Q

What are the main adverse effects of levetiracetam (4)?

A
  • Dizziness
  • Somnolence
  • Fatigue
  • Headache
30
Q

Why is levetiracetam preferable to other medication?

A
  • The metabolism of levetiracetam has no effect on the cytochrome P450 enzyme system, so it is favourable in terms of no drug-drug interactions