Anti-convulsants

Question 1

Haematological SE of Carbamazepine?

Answer 1

General BM depression with agranulocytosis in the first months of treatment

Question 2

A trial of what medication is recommended in Infantile spasms (or West syndrome)

Answer 2

High dose steroids (or ACTH in UK)

Question 3

What particular anticonvulsant would you trial in infantile spasms known to be secondary to tuberous sclerosis?

Answer 3

Vigabatrin

Question 4

What is an irreversible SE of Vigabatrin?

Answer 4

Loss of peripheral vision

Question 5

First line management for childhood absence epilepsy?

Answer 5

Ethosuximide

Then Sodium Valproate

Question 6

1st line anticonvulsant for temporal lobe epilepsy?

Answer 6

Carbamazepine

2nd line phenytoin

Question 7

Which anticonvulsants act on GABA?

Answer 7

Benzodiazepines
Vigabatrin
Topiramate (?)

Question 8

Which anticonvulsants act by inhibiting voltage gated sodium channels?

Answer 8

CBZ
Phenytoin/Phenobarbitone
Valproate
Topiramate
lamotrigine (?)
Oxcarbazepine 
Zonisamide

Question 9

What should Carbamazepine NOT be used for?

Answer 9

Generalised epilepsies

Question 10

Does Carbamazepine inhibit or induce liver enzyme system CYP-450?

Answer 10

Induction

Question 11

What should one take care with Carbamazepine in Asian populations?

Answer 11

SJS (HLA-B* 1502 in Asian population)

Question 12

Does phenytoin induce or inhibit liver enzymes?

Answer 12

Phenytoin induces CYP-450 liver enzymes

Question 13

Side effects of phenytoin?

Answer 13

Rash/SJS/Serum sickness
hirsutism/gum hypertrophy
Osteoporosis
Severe idiosyncratic reactions

Question 14

Side effects of phenobarbitone?

Answer 14

Rash
Megaloblastic anaemia
Osteomalacia (increased Vit D breakdown)

Question 15

Contra-indications for Sodium Valproate?

Answer 15

Liver disease
Mitochondrial disease
<2yrs
Undiagnosed intellectual disability

Question 16

Side effects of Sodium Valproate?

Answer 16

Dose related tremor/irritability/confusion
Hepatotoxicity
Weight gain
Alopecia
Pancreatitis
Thrombocytopenia

Question 17

Action of benzodiazepines?

Answer 17

Bind to GABA site (increase Cl influx)

Question 18

Why should Valproate and Lamotrigine be used very carefully together?

Answer 18

Valproate INHIBITS metabolism of lamotrigine and increases the half-life

Question 19

Most common side effect of Lamotrigine?

Answer 19

Rash (increase the dose very slowly to minimise the risk of rash development)

Question 20

Action of Vigabatrin?

Answer 20

Irreversible inhibitor of GABA transaminase

produces dose dependent increase in CSF GABA concentration

Question 21

Irreversible side effect of Vigabatrin?

Answer 21

Visual field constriction (retinal toxicity) and retinopathy (20% of patients have changes on review)

Question 22

Topiramate SE?

Answer 22

Weight Loss
Nephrolithiasis
Dose dependent cognitive side effects (10% have word finding difficulties)

Question 23

SE of Keppra?

Answer 23

Behavioural disorders
Psychosis
Sleep disturbance

Question 24

Cross reaction to Oxcarbazepine if allergy to Carbamazepine?

Answer 24

30% cross-reaction

Question 25

MOA of Ethosuximide (Zorontin)

Answer 25

Enhancement of non-GABA mediated inhibition | Blocks T-type Ca channels

Question 26

Which anti-convulsant medications induce hepatic enzymes?

Answer 26

Phenobarbitone Phenytoin Carbamazepine

Question 27

Which commonly used AED causes hepatic enzyme inhibition?

Answer 27

Sodium Valproate

Question 28

Which AEDs are considered effective for primary generalised epilepsies? (5)

Answer 28

``` Sodium valproate Topiramate Lamotrigine Keppra Zonisamide ```

Question 29

What are the typical dose related side effects of AEDs?

Answer 29

``` Sedation Headache GI irritation Unsteadiness (ataxia) Dysarthria Behavioural disturbance ```

Question 30

Define idiosyncratic

Answer 30

Unpredictable, potentially fatal drug reactions not related to dose

Question 31

What idiosyncratic reactions have been documented with phenytoin? (4)

Answer 31

hepatic dysfunction movement disorder SJS fulminant hepatic failure

Question 32

What idiosyncratic reactions: carbamazepine (5)

Answer 32

``` Leukopenia Aplastic anaemia Thrombocytopenia Hepatic dysfunction Rashes ```

Question 33

Idiosyncratic reactions: ethosuxamide (3)

Answer 33

Leukopenia Pancytopenia Rashes

Question 34

Idiosyncratic reactions: valproate (6)

Answer 34

``` Fulminant hepatic failure Hyperammonemia Pancreatitis Thrombocytopenia Rash Stupor ```