Epilepsy

Question 1

Which antiepileptics can be taken OD?

Answer 1

Lamotrigine
Phenobarbital
Phenytoin
Perampanel

Question 2

What are the stages of management for epilepsy?

Answer 2

Monotherapy with first line antiepileptic drug
If fails, monotherapy with second antiepileptic drug
If fails, combination therapy
If fails, revert to therapy (monotherapy/combo) which had best efficacy/tolerability balance

Question 3

What are the risks of using combo therapy?

Answer 3

Increased risk of interactions and adverse effects

Question 4

What are the three MHRA warnings for antiepileptics?

Answer 4

1. Risk of suicidal thoughts and behaviour
2. Switching brands of antiepileptics
3. Antiepileptic drugs in pregnancy

Question 5

Which antiepileptics are category one and what does this mean?

Answer 5

Carbamazepine, phenytoin, primidone, phenobarbital

Should be maintained on the same product

Question 6

What is antiepileptic hypersensitivity syndrome?

Answer 6

Rare but potentially fatal syndrome associated with some antiepileptics

Question 7

What are the symptoms and the onset for symptoms of antiepileptic hypersensitivity syndrome?

Answer 7

Usual onset 1-8 weeks after exposure
Symptoms: rash, fever, lymphadenopathy
Other systemic signs: liver dysfunction, haematological, renal, pulmonary abnormalities, vasculitis, multi-organ failure.

Question 8

How would you manage the antiepileptic if someone experiences antiepileptic hypersensitivity syndrome?

Answer 8

Withdraw drug immediately, must not be re-exposed to drug

Question 9

Which drugs can cause antiepileptic hypersensitivity syndrome?

Answer 9

Carbamazepine
Lacosamide
Lamotrigine
Oxcarbazepine 
Phenobarbital
Phenytoin
Primidone
Rufinamide 
Theoretical risk with eslicarbazepine, steripentol, zonisamide

Question 10

Which antiepileptics are relatively safer in pregnancy?

Answer 10

Lamotrigine and levetiracetam

Question 11

Which antiepileptics are teratogenic?

Answer 11

VALPROATE
Carbamazepine
Phenytoin
Phenobarbital 
Topiramate

Question 12

What dose of folic acid should women planning pregnancy whilst on antiepileptics take?

Answer 12

5mg OD from before conception until 12 weeks

Question 13

Which antiepileptics readily transfer into breast milk?

Answer 13

ZELP
Zonisimide
Ethosuximide
Lamotrigine
Primidone

Question 14

Which antiepileptics accumulate in infant during breastfeeding due to slower metabolism?

Answer 14

Phenobarbital

Lamotrigine

Question 15

Treatment for focal seizures with or without secondary generalisation

Answer 15

First line: carbamazepine, lamotrigine

Other: oxcarbazepine, sodium valproate, levetiracetam

Question 16

Treatment for tonic-clonic seizures

Answer 16

Sodium valproate first line, can use lamotrigine if not suitable, carbamazepine

Question 17

Treatment for absence seizures

Answer 17

Ethosuximide or sodium valproate

Question 18

Treatment for myoclonic seizures?

Answer 18

Sodium valproate

Question 19

Treatment for atonic or tonic seizures?

Answer 19

Sodium valproate

Question 20

Which antiepileptics inhibit sucking reflex in infant?

Answer 20

Phenobarbital and primidone

Question 21

Which antiepileptics can cause blood dyscrasias?

Answer 21

C Vet Plz
Carbamazepine
Valproate
Ethosuximide
Topiramate 
Phenytoin
Topiramate
Zonisamide

Question 22

What is the MHRA warning for gabapentin?

Answer 22

Risk of severe respiratory depression

Question 23

Is sodium valproate an enzyme inducer or inhibitor?

Answer 23

Inhibitor

Question 24

Which antiepileptics are enzyme inhibitors?

Which important medicines do they interact with?

Answer 24

Carbamazepine, phenytoin, phenobarbital

Interacts with warfarin and oral contraceptives

Question 25

What is the therapeutic range for phenytoin?

Answer 25

10-20mg/L

Question 26

What types of seizures does phenytoin exacerbate?

Answer 26

Absence and myoclonic

Question 27

Why is is important to monitor plasma phenytoin concentration?

Answer 27

Non-linear relationship so small changes in dose/missed doses/changes in drug absorption cause a large change in plasma concentration

Question 28

What are the signs of phenytoin toxicity?

Answer 28

``` SNAtCHeD Slurred speech Nystagmus Ataxia Confusion Hyperglycaemia Diplopia, blurred vision ```

Question 29

Dose conversion between pheytoin sodium and phenytoin base?

Answer 29

100mg phenytoin sodium = 92mg phenytoin base

Question 30

What are the side effects of phenytoin?

Answer 30

1. Changes in appearance - coarsening of facial features, acne, hirsutism, gingival hypertrophy 2. Blood dyscrasias (antifolate) so monitor FBC and for signs of infection 3. Antiepileptic hypersensitivity syndrome 4. Rashes - reintroduce cautiously but discontinue if recurs, steven johnson syndrome 5. Low vitamin D (osteomalacia and rickets) - consider vit D supplements and monitor levels 6. Hepatotoxicity - discontinue immediately if occurs, monitor LFTs 7. Suicidal ideation

Question 31

What are the risks with IV phenytoin?

Answer 31

MHRA alert - error prone Side effects: arrythmias, cardiovascular collapse, respiratory arrest and with fosphenytoin (prodrug - severe cardiovascular reactions)

Question 32

Which drug classes interact with phenytoin?

Answer 32

Question 33

Is phenytoin an enzyme inducer or inhibitor?

Answer 33

Inducer - will decrease concentrations of other drugs

Question 34

Is phenytoin an enzyme inducer or inhibitor?

Answer 34

Inducer - will decrease concentrations of other drugs

Question 35

What types of seizures is carbamazepine used in?

Answer 35

First line in focal seizures and tonic-clonic seizures

Question 36

What types of seizures does carbamazepine exacerbate?

Answer 36

Atonic, clonic and myoclonic

Question 37

What is the therapeutic range for carbamazepine? When do you measure it?

Answer 37

4-12mg/L | After 1 to 2 weeks

Question 38

What are the signs and symptoms of toxicity of carbamazepine?

Answer 38

``` I HANDBAG Incoordination Hyponatremia Ataxia Nystagmus Drowsiness Blurred vision and diplopia Arrythmias Gastrointestinal disturbance (nausea, vomiting, diarrhoea) ```

Question 39

What are the side effects of carbamazepine?

Answer 39

1. Blood dyscrasias e.g. leucopenia, thrombocytopenia 2. Hepatotoxicity 3. Antiepileptic hypersensitivity syndrome 4. Rashes - Steven Johnson syndrome 5. Hyponatremia 6. Dose related and dose limiting: headache, ataxia, drowsiness, n+v, blurred vision, unsteadiness, allergic skin reactions

Question 40

What interactions does carbamazepine have?

Answer 40

Question 41

Is carbamazepine an enzyme inducer or inhibitor?

Answer 41

Inducer - reduces concentration of other medicines

Question 42

What are the side effects of sodium valproate?

Answer 42

1. Hepatotoxicity (potentially fatal) - discontinue if prolonged PTT 2. Pancreatitis 3. Blood dyscrasias