CPTP 3.22 Antiepileptics

Question 1

Describe Grand Mal epilepsy

Answer 1

• tonic clonic
• random frequency
• loss of consciousness, bladder control
• post ictal coma

Question 2

Describe Petit Mal epilepsy

Answer 2

• absence seizure
• regular frequency (3Hz)
• no motor symptoms
• no post ictal coma

Question 3

Describe partial epilepsy

Answer 3

• localised
• hallucinations if temporal lobe affected
• bizarre movements if motor cortex affected

Question 4

Describe Status Epilepticus

Answer 4

• continuous tonic clonc seizures, unconsciousness
• fever sweating, hypertension
• anoxia/hypoxia

Question 5

Drugs for grand mal

Answer 5

Carbamazepine, phenytoin, valproate, lamotrigine, barbiturates

Question 6

Drugs for petit mal

Answer 6

Ethosuxamide

Question 7

Drugs for status epilepticus

Answer 7

Phenytoin, BZDs

Question 8

Adjunct anti-epileptic drugs

Answer 8

Gabapentin, Vigabatrin, Tigabide

Question 9

Phenobarbitone, pentabarbitone

Pharmacodynamics + clinical use

Answer 9

Positively modulate GABA-A receptor, increases postsynaptic GABAergic transmission

Clinical use:
Grand mal

Question 10

BZDs: Clonazepam, clobazam, diazepam

Pharmacodynamics + clinical use

Answer 10

• Positively modulate GABA-A receptor, increases postsynaptic GABAergic transmission
• increases frequency of Cl channel opening

Clinical use:
status epilepticus

Question 11

Valproate

Pharmacodynamics + clinical use

Answer 11

-Blocks repetitive firing from voltage gated Na channels

Clinical use:
Grand mal, partial

Question 12

Carbamazepine

Pharmacodynamics + clinical use + significant side effects

Answer 12

-Blocks repetitive firing from voltage gated Na channels

Clinical use:
Grand mal, partial epilepsy, trigeminal neuralgia

Significant side effects:
Agranulocytosis, aplastic anaemia

Question 13

Lamotrigine

Pharmacodynamics + clinical use

Answer 13

-Blocks repetitive firing from voltage gated Na channels

Clinical use:
Grand mal, partial

Question 14

Phenytoin (hydantoin)

Pharmacodynamics + clinical use + significant side effects

Answer 14

-Blocks repetitive firing from voltage gated Na channels

Clinical use:
status epilepticus

Significant side effects:
nystagmus

Question 15

Ethosuximide (succinimide)

Pharmacodynamics + clinical use

Answer 15

-Blocks T type calcium channels (involved in generation of 3Hz activity in thalamic neurons)

Clinical use:
Petit mal (ineffective against Grand Mal cos doesn't enhance GABA)

Question 16

Vigabatrin

Pharmacodynamics + clinical use

Answer 16

-Blocks GABA metabolism (GABA transaminase inhibitor)

Clinical use:
adjunct therapy

Question 17

Tigabide

Pharmacodynamics + clinical use

Answer 17

-Blocks GABA reuptake (blocks GABA transporter-1)

Clinical use:
adjunct therapy

Question 18

Gabapentin

Pharmacodynamics + clinical use

Answer 18

-GABA agonist

Clinical use:
adjunct therapy

Question 19

Major side effects of anti-epileptic drugs:

GI, CNS, psych, others

Answer 19

GI: N&V, anorexia

CNS: drowsiness, dizziness, ataxia, cognitive defects

Psych: depression, euphoria, psychosis, agitation, restlessness, night tremor

Others: blood disorders, rashes, gingivial hyperplasia, hair loss, hirsuitism