Anticonvulsants Core Drugs

Question 1

What is the primary mechanism of action of lamotrigine?

Answer 1

1. Blocks voltage gated Na+ channels preventing Na+ influx

2. Prevents depolarisation of glutamatergic neurones and reduces glutamate excitotoxicity

Question 2

What is the drug target for lamotrigine?

Answer 2

Voltage gated Na+ channels

Question 3

What are the common side effects of lamotrigine?

Answer 3

• Rash

- drowsiness

Question 4

What are the less common but serious side effects of lamotrigine?

Answer 4

• Steven-Johnson’s syndrome

- suicidal thoughts

Question 5

How do you reduce the frequency and severity of allergic skin reactions?

Answer 5

Introducing lamotrigine gradually

Question 6

How commonly were these drugs prescribed in 2020 in West London?

Answer 6

• Lamotrigine: 94th
• Sodium valproate: 78th
• Diazepam: 61st
• Levetiracetam: 74th

Question 7

What is the primary mechanism of. action for sodium valproate?

Answer 7

1. Inhibition of GABA transaminase prevents the breakdown of GABA
2. Increases GABA concentrations directly in the synapse presynaptically
3. Also indirectly prolongs GABA in the synapse due to the fact that extraneuronal metanolism of GABA is slowed which also slows GABA removal from the synapse

Question 8

What is the drug target of sodium valproate?

Answer 8

GABA transaminase

Question 9

What are the common side effects of sodium valproate?

Answer 9

• Stomach pain
• diarrhoea
• drowsiness
• weight gain
• hair loss

Question 10

What are the serious side effects of sodium valproate?

Answer 10

• hepatotoxicity
• teratogenicity
• pancreatitis

Question 11

What does a broad CYP enzyme inhibitor cause?

Answer 11

increases serum concentration of many co-administered drugs

Question 12

What is the primary mechanism of action for diazepam?

Answer 12

1. Increases choride ion influx in response to GABA binding at the GABA A receptor
2. Increased chloride ion influx associated with hyperpolarisation of excitatory neurones

Question 13

What is the drug target for diazepam?

Answer 13

Benzodiazepine site on the GABA A receptor

Question 14

What are the common side effects of diazepam?

Answer 14

• Drowsiness

- Respiratory depression (if i.v. or at high dose)

Question 15

What are the uncommon but serious side effects of diazepam?

Answer 15

1. Haemolytic anaemia

2. jaundice

Question 16

What. is the main reason that diazepam is not sued for long term?

Answer 16

not used for long term suppression of seizures is due to the development of tolerance

Question 17

What type of schedule is diazepam and what does this mean?

Answer 17

Diazepam is a Schedule 4 controlled drug - addiction prone individuals more likely to become dependent on diazepam

Question 18

What is the primary mechanism of action of levetiracetam?

Answer 18

1. Inhibition of the synaptic vesicle protein SV2A
2. Inhibits this protein and prevents vesicle exocytosis
3. A reduction in glutamate secretion is reduces glutamate excitotoxicity

Question 19

What is the drug target of levetiracetam?

Answer 19

Synaptic vesicle protein SV2A

Question 20

What are the common side effects of levetiracetam?

Answer 20

• dizziness
• somnolence
• fatigue
• headache

Question 21

Does levetiracetam have drug interactions?

Answer 21

The metabolism of levetiracetam has no effect on the cytochrome P450 enzyme system so it is favorable in terms of no drug–drug interactions