Anticonvulsants

Question 1

What is the prevalence of epilepsy in the UK?

Answer 1

7-9% of the population

Question 2

Recall the 5 types of generalised seizure

Answer 2

1. Tonic/clonic
2. Absence
3. Tonic/atonic
4. Myoclonic
5. Status epilepticus

Question 3

Describe the presentation of a tonic/clonic seizure

Answer 3

Loss of consciousness, muscle stiffening, twitching + jerking –> deep sleep –> wake

Question 4

What is the most common type of generalised seizure?

Answer 4

Tonic/clonic

Question 5

Describe the presentation of an absence seizure

Answer 5

Brief staring episodes with behavioural arrest

Question 6

Describe the presentation of a tonic/atonic seizure

Answer 6

"Tonic" = sudden stiffening of muscles 
"Atonic" = loss of muscle control

Question 7

Describe the presentation of a myoclonic seizure

Answer 7

Sudden, brief muscle contractions

Question 8

How can tonic/atonic seizures and myoclonic seizures be differentiated

Answer 8

Presentations similar therefore use EEG

Question 9

Describe the presentation of a status epilepticus

Answer 9

More than 5 mins of chronic seizure activity

Question 10

What is a partial/ focal seizure?

Answer 10

Seizure that begins within a particular area of brain and may spread out

Question 11

Recall the types of partial/ focal seizure

Answer 11

Retained awareness = simple

Impaired awareness = complex

Question 12

Briefly summarise the transmission events at glutametergic synapses

Answer 12

VGSC and VGKC action –> AP
Glu stored in vesicle which is bound to presynaptic membrane via SV2A
Upon release, acts on excitatory receptors

Question 13

Recall 3 approaches to inhibiting the excitatory effect of glutamate

Answer 13

Inhibit VGSCs
Inhibit VGCCs
inhibit SV2A docking protein

Question 14

Give 2 examples of drugs that inihibit VGSCs in glutamatergic neurons

Answer 14

Carbamazepine

Lamotrigine

Question 15

Recall the MOA of carbamazepine

Answer 15

Stabilises inactive state of VGSC

Question 16

Recall 2 advantages and 2 disadvantages of carbamazepine use

Answer 16

Advantages:
1. Fast onset
2. Long DOA
Disadvantages:
1. Low selectivity
2. Enzyme inducer --> many DDIs

Question 17

Recall the indications for carbamazepine

Answer 17

Tonic/clonic seizures and partial/focal seizures

Question 18

What are the side effects associated with carbamazepine in individuals with a certain HLA haplotype, and what is this HLA allele?

Answer 18

HLA-B*1502
Severe skin conditions
Stephen Johnson syndrome
Toxic epidermal necrolysis

Question 19

Recall the MOA of lamotrigine

Answer 19

Pushes VGSCs into the inactive state

Question 20

Suggest an advantage of lamotrigine over carbamazepine as an anticonvulsant

Answer 20

Lamotrigine has higher specificity for Glu neurons

Question 21

Recall the indications for lamotrigine

Answer 21

Tonic/clonic seizures and absence seizures

Question 22

Recall an anticonvulsant that acts by inhibiting Glu vesicle docking

Answer 22

Levetiracetam

Question 23

Recall the MOA of levetirecetam

Answer 23

Binds SV2A to prevent Glu release

Question 24

Recall the MOA of topiramate

Answer 24

Inhibits NMDA and kainate Glu receptors

Question 25

Recall the indications for topiramate

Answer 25

Myoclonic seizures

Question 26

Recall the general PK of anticonvulsant drugs

Answer 26

Fast onset and long t1/2

Question 27

Recall 2 anticonvulsant drugs that work by interacting with GABA transmission

Answer 27

Diazepam | Sodium valproate

Question 28

What is the MOA of valproate?

Answer 28

Inhibits GABA-T to increase synaptic GABA levels

Question 29

How is diazepam usually administered in a seizure?

Answer 29

Rectal gel

Question 30

Recall the indications for diazepam

Answer 30

Status epilepticus

Question 31

Recall the indications for valproate

Answer 31

All forms of epilepsy apart from SE

Question 32

Recall the drugs that are indicated for tonic/clonic seizure treatment

Answer 32

Carbamazepine Lamotrigine valproate

Question 33

Recall the drugs that are indicated for absence seizure treatment

Answer 33

Ethosuximide Lamotrigine valproate

Question 34

Recall an anticonvulsant that acts via VGCC interference

Answer 34

Ethosuximide

Question 35

What type of VGCC are found in the CNS?

Answer 35

T-type (transient)

Question 36

Recall the indications for ethosuximide

Answer 36

ONLY absence seizures

Question 37

Recall the drugs that are indicated for tonic/atonic seizure treatment

Answer 37

valproate

Question 38

Recall the drugs that are indicated for myoclonic seizure treatment

Answer 38

Levetiracetam Topiramate valproate

Question 39

Recall the drugs that are indicated for simple partial seizure treatment

Answer 39

valproate Carbamazepine Lamotrigine Levetiracetam