Pharmacology: anti-seizure drugs

Question 1

What are seizures?
Does it often start within a small group of neurons, and then spread to other brain regions?

Answer 1

Uncontrolled/abnormal discharge in part of the brain
Yes

Question 2

What factors can lead to seizures?
Define epilepsy

Answer 2

Brain lesions, tumours, chemical imbalance, drugs, excess alcohol, alcohol withdrawal, stress, sleep deprivation, fever
Epilepsy: recurrent, periodic seizures

Question 3

TYPES OF SEIZURES
What are the two main categories of seizures?

Answer 3

Focal onset - localised
General onset - involve the whole brain

Question 4

TYPES OF SEIZURES
Two types of focal onset seizures?

Answer 4

Aware: simple partial seizure, with motor/sensory/autonomic symptoms

Impaired awareness: complex partial seizure, with various symptoms

Question 5

TYPES OF SEIZURES
Two types of generalised onset seizures?

Answer 5

Motor (tonic-clonic): initial rigidity followed by convulsions; formerly called “grand mal” seizures

Non-motor (absence): stop and stare vacantly with little motor disturbance; formerly called “petit mal”

Question 6

Drug to treat seizures?

Answer 6

Anti convulsants

Question 7

ANTI CONVULSANTS
General MOA?
3x mechanisms to enable this?

Answer 7

Slow down the nerves that overfire during epilepsy
Increased GABA ativity
Decreased sodium channel signalling
Block calcium channel signalling

Question 8

ANTI CONVULSANTS
4 general ADRs?

Answer 8

Sedation
Confusion
Skin rashes
Teratogenicity

Question 9

ANTI CONVULSANTS
2 drugs which enhance GABA activity?

Answer 9

Benzodiazepines
Valproate

Question 10

ANTI CONVULSANTS
Benzodiazepines - MOA?
Valproate: MOA, ADRs?

Answer 10

Question 11

ANTI CONVULSANTS
3 drugs which inhibit sodium channel signalling?

Answer 11

Question 12

ANTICONVULSANTS
Carbamazepine:
- What is special about how it acts?
- ADRs?

Answer 12

Question 13

ANTICONVULSANTS
Phentoin
- What is special about it?
- ADRs?

Answer 13

Question 14

ANTI CONVULSANTS
Phentoin
Absorption
- What route?
- Well absorbed?

Distribution
- Is it highly protein bound?
- Can introducing other protein binding agents (eg. valproate) result in displacement of phentoin –> increased free concentration?
- Can plasma levels vary greatly between people?

Metabolism
- Can it become saturated?

Answer 14

Oral
Yes

Yes
Yes
Yes

Yes

Question 15

ANTI CONVULSANTS
Lamotrigine
- What does it also do?

Answer 15

Question 16

ANTICONVULSANTS
What are the two drugs involved?

Answer 16

Question 17

ANTICONVULSANTS
Ethosuximide
- What effect does it have from blocking calcium channels?

Answer 17

Question 18

ANTI CONVULSANTS
Gabapentin and pregabalin
MOA?
How is it excreted?

Answer 18

Question 19

For absence seizures in children, which drug is first line? Which is second line?

Answer 19

First line: ethosuximide
Second line: valproate