Pharmacology of Epilepsy

Question 1

What is generalized tonic-clonic epilepsy?

Answer 1

Seizures characterized by a tonic stage (loss of consciousness, body stiffens) shortly followed by a second clonic stage (contraction and relaxation of muscles)

Question 2

What is an absence seizure?

Answer 2

Seizure characterised by loss of awareness of surroundings, the patient may have a blank stare and will not respond

Question 3

What is a myoclonic seizure?

Answer 3

brief, shock-like jerks of a muscle or a group of muscles

Question 3

What is the drug target for Lamotrigine?

Answer 3

Voltage gated sodium channels

Question 4

What is the primary mechanism of action of Lamotrigine?

Answer 4

Blocks voltage gated sodium channels preventing sodium influx. Prevents depolarisation of glutamatergic neurones and reduces glutamate excitotoxicity

Question 5

What are the main side effects of Lamotrigine?

Answer 5

Rash and drowsiness. Suicidal thoughts

Question 6

What is the best way to use Lamotrigine to prevent side effects?

Answer 6

Gradual introduction

Question 7

What is the drug target for Sodium Valproate?

Answer 7

GABA transaminase

Question 8

What is the primary mechanism of action of Sodium Valproate?

Answer 8

Inhibition of GABA transaminase prevents the breakdown of GABA, increasing GABA concentrations in the synapse.

Question 9

What are the main side effects of the use of Sodium Valproate?

Answer 9

Stomach pain and diarrhoea, drowsiness, weight gain, hair loss. Hepatotoxicity, Teratogenicity and pancreatitis

Question 10

What is the drug target for diazepam?

Answer 10

Benzodiazepine site on the GABA A receptor

Question 11

What is the mechanism of action of diazepam?

Answer 11

Increases chloride ion influx in response to GABA binding to GABA A receptor causing hyperpolarisation of excitatory neurones

Question 12

What side effects are associated with diazepam?

Answer 12

Drowsiness, respiratory depression, haemolytic anaemia, jaundice

Question 13

Why is diazepam not used for long term supression of seizures?

Answer 13

Development of tolerance

Question 14

What is the drug target for Levetiracetam?

Answer 14

synaptic vesicle protein SV2A

Question 15

what are the therapeutic objectives of antiepileptic drug therapy?

Answer 15

to eliminate seizures or reduce their frequency, to avoid adverse effects associated with long term treatment

Question 16

what is the primary mechanism of action of levetiracetam?

Answer 16

inhibition of synpatic vesicle SV2A preventing exocytosis, reducing glutamate excitability

Question 17

what are the common side effects associated with levetiracem use?

Answer 17

dizziness, somnolence, fatigue and headache

Question 18

what makes levetiracetam a favourable drug?

Answer 18

the metabolism of levetiracetam has no effect on cytochrome P450 enzyme so there is no drug-drug interactions

Question 19

why is there a difference in the epileptic treatment between men and women?

Answer 19

Valproate causes neural tube defects, decreased IQ and autism after in utero exposure

Question 20

What affect does taking the combined oral contraceptive pill (COC) have on lamotrigine?

Answer 20

coadministration of COC leads to reduced lamotrigine levels in the blood