Epilepsy 1: Control, management, categories, Driving

Question 1

When choosing an antiepileptic drug, what should be considered first in order to determine the choice of treatment?

Answer 1

1) presenting epilepsy syndrome

2) if syndrome is not clear, the seizure type should determine the choice of treatment

Question 2

The dosage frequency is often determined by what characteristic of antiepileptic drugs?

Answer 2

plasma-drug half-life

Question 3

Most antiepileptics, when used in the usual dosage, can be given twice daily. Which antiepileptics can be given once daily because of their long half-lives? (4)

Answer 3

1) Lamotrigine
2) Perampanel
3) Phenobarbital
4) Phenytoin
↳ given once daily at bedtime

Question 4

With large doses, some antiepileptics may need to be given more frequently. Explain why

Answer 4

To avoid adverse effects associated with high peak plasma-drug concentration

Question 5

Discuss if monotherapy or combination therapy is preferred in epilepsy

Answer 5

1) single antiepileptic drug should be prescribed wherever possible. When monotherapy with a first-line antiepileptic drug has failed, monotherapy with a second drug should be tried
2) the diagnosis should be checked before starting an alternative drug if the first drug showed lack of efficacy.

Question 6

1) Explain how you would go about changing a patient from one antiepileptic drug to another.
2) What are the problems with combination therapy?

Answer 6

1) slowly withdraw the first drug only when the new regimen has been established.
2) Combination therapy may be necessary, but increases the risk of adverse effects and drug interactions. If combination therapy is not beneficial revert back to previous regimen that provided best results

Question 7

Antiepileptic drugs have been divided into three risk-based categories. For Category 1 drugs- doctors are advised to ensure that their patient is maintained on a specific manufacturer’s product. list the drugs that fall within this category (4)

Answer 7

1) Carbamazepine
2) Phenobarbital
3) Phenytoin
4) Primidone

Question 8

Category 2 drugs - the need for continued supply of a particular manufacturer’s product should be based on clinical judgement and consultation with the patient and/or carer. List the drugs that fall within this category (10)

Answer 8

1) Clobazam, Clonazepam
2) Lamotrigine, Oxcarbazepine, Eslicarbazepine
3) Valproate, Topiramate
4) Zonisamide, Rufinamide
5) Perampanel

Question 9

Category 3 drugs - unnecessary to ensure that patients are maintained on a specific manufacturer’s product as therapeutic equivalence can be assumed. List the drugs that fall within this category (8)

Answer 9

1) Levetiracetam, Brivaracetam
2) Gabapentin, Pregabalin
3) Lacosamide, Ethosuximide
4) Tiagabine, Vigabatrin

Question 10

Antiepileptic hypersensitivity syndrome is a rare but potentially fatal syndrome associated with some antiepileptic drugs. What are the symptoms of this condition?

Answer 10

1) usually start between 1 and 8 weeks of exposure
2) fever, rash, and lymphadenopathy are common
3) Other systemic signs include liver dysfunction, haematological, renal, and pulmonary abnormalities, vasculitis, and multi-organ failure

Question 11

What should be done if signs or symptoms of hypersensitivity syndrome occur?

Answer 11

Drug should be withdrawn immediately, the patient must not be re-exposed, and expert advice should be sought

Question 12

which drugs are commonly associated with antiepileptic hypersensitivity syndrome?

Answer 12

1) carbamazepine, lamotrigine, oxcarbazepine
2) lacosamide
3) phenobarbital, phenytoin, primidone
4) rufinamide

Question 13

MHRA has advised that all antiepileptic drugs are associated with a small increased risk of suicidal thoughts and behaviour. state how quickly these symptoms occur and what advice should be given to patients.

Answer 13

1) early as one week after starting treatment

2) seek medical advice if you develop any mood changes, distressing thoughts, or feelings about suicide

Question 14

Interactions between antiepileptics may increase toxicity without a corresponding increase in antiepileptic effect. What are interactions commonly caused by?

Answer 14

1) Interactions are usually caused by hepatic enzyme induction or inhibition
2) displacement from protein binding sites is not usually a problem

Question 15

Antiepileptic drugs should be withdrawn under specialist supervision, discuss how this is managed

Answer 15

1) Avoid abrupt withdrawal, reduction in dosage should be gradual and, in the case of barbiturates, withdrawal of the drug may take months
2) In patients receiving several antiepileptic drugs, only one drug should be withdrawn at a time.

Question 16

What can abrupt withdrawal of barbiturates and benzodiazepines cause?

Answer 16

precipitate severe rebound seizures

Question 17

If a patient has a seizure they must stop driving and inform the DVLA immediately. How long must a patient who has had their first unprovoked epileptic seizure or a single isolated seizure stop driving for?

Answer 17

1) Not drive for 6 months
2) Driving may then be resumed, if specialist declares patient is fit to drive and investigations do not suggest a risk of further seizures

Question 18

Patients with established epilepsy may drive if they are not a danger to the public and are compliant with treatment. What other criteria must they meet?

Answer 18

1) must be seizure-free for at least one year

2) They must not have a history of unprovoked seizures

Question 19

Patients who have had a seizure while asleep are not permitted to drive for one year from the date of each seizure, unless what criteria is met?

Answer 19

1) seizures occurring only ever while asleep over the course of at least one year or;
2) an established pattern of purely asleep seizures over three years if the patient has previously had seizures whilst awake

Question 20

What are the DVLA recommendations regarding driving during medication changes or withdrawal ?

Answer 20

1) Avoid during medication changes or withdrawal for 6 months after last dose
2) If a seizure occurs license will be revoked for 1 year; relicensing may be considered earlier if treatment has been reinstated for 6 months and no further seizures have occurred.