CHAPTER 4: CNS: Epilepsy Flashcards
Most anti-epileptics are given twice daily. Which can be given once daily at bedtime due to long half life? (4)
- Lamotrigine
- Perampanel
- Phenobarbital
- Phenytoin
The recommended management for epilepsy is monotherapy with a first-line anti-epileptic. What is the next option and the one after that?
- Monotherapy - alternative anti-epileptic
3. Combination therapy - 2 or more drugs
When switching from one drug to the other, how is the old drug withdrawn?
Start the new drug THEN begin withdrawing the old drug
What is the MHRA warning associated with anti-epileptic drugs in general?
Potential harm can result from switching between brands, including loss of seizure control
What are the category 1 anti-epileptics that should never be brand-switched? (4)
- Phenytoin
- Phenobarbital
- Primidone
- Carbamazepine
What are the category 3 anti-epileptics where it is unnecessary to maintain the same brand? (7)
- Levetiracetam
- Lacosamide
- Tigabine
- Ethosuximide
- Vigabatrin
- Gabapentin
- Pregabalin
What are the initial symptoms of anti-epileptic hypersensitivity syndrome? (3)
- Fever
- Rash
- Lymphadenopathy
As well as fever, rash and lymphadenopathy, what are the other systemic signs of anti-epileptic hypersensitivity syndrome? (6)
- Liver dysfunction
- Renal
- Haematological
- Pulmonary
- Vasculitis
- Multi-organ failure
Give 4 examples of anti-epileptics that have been associated with anti-epileptic hypersensitivity syndrome
- Carbamazepine
- Lamotrigine
- Phenytoin
- Phenobarbital
If a patient experiences anti-epileptic hypersensitivity syndrome, can they be re-exposed to that drug at a later time?
No
As well as brand, what is another MHRA alert for all anti-epileptics?
Suicidal thoughts and behaviour
Which symptoms, related to suicidal thoughts and behaviour, should patients seek medical advice if they experience?(4)
- Mood changes
- Distressing thoughts
- Feelings about suicide
- Self-harm
Anti-epileptics have many drug interactions which can be complex, variable and unpredictable. They can lead to both toxicity or treatment failure. What are interactions usually caused by?
Enzyme induction or inhibition
Give 3 anti-epileptics with an enzyme INDUCING effect
- Carbapmazepine
- Phenytoin
- Phenobarbital
Give 1 anti-epileptic with an enzyme INHIBITING effect
Sodium Valproate
Should anti-epileptics be stopped suddenly?
No, gradual withdrawal
How long can withdrawal of anti-epileptic drugs take?
Months
Which agency must all people with epilepsy alert?
The DVLA
If a patient has their first, single/isolated unprovoked seizure, how long are they unable to drive?
6 months
If a patient has established epilepsy, is compliant with follow-ups and treatment, how long must they remain seizure-free for them to be able to drive?
1 year
If a patient only gets seizures while they are asleep, how long after this is diagnosed are they able to drive? Must be able to prove that seizures only happen at night
1 year
What is the DVLA’s recommendation regarding driving while changes to anti-epileptic medications are being made?
Not to drive during that period
If a patient is withdrawn on anti-epileptic medicines, how long after their last dose are they unable to drive?
6 months
Which anti-epileptic has the highest risk of teratogenicity?
Sodium Valproate
Which congenital malformation is sodium valproate most associated with?
Neural tube defects
At which point in the pregnancy is teratogenicity of highest risk?
First trimester
Which anti-epileptic is associated with a risk of cleft palate in the first trimester?
Topiramate
As well as Valproate, all anti-epileptics carry a risk of teratogenicity including phenytoin, primidone, phenobarbital, lamotrigine and carbamazepine. What is the advice for all women of child-bearing age?
Effective contraception to avoid unplanned pregnancy
Related to pregnancy, which class of drugs do anti-epileptics interact with?
Hormonal contraception, decreases the efficacy
If pregnancy is discovered in a woman taking anti-epileptics, what is the chance that the baby will have no malformations at all?
90%
If pregnancy is discovered in a woman taking anti-epileptics, should she be advised to stop taking treatment?
NO
Which supplement should a pregnant woman taking anti-epileptics take?
Folate
If a woman taking anti-epileptics wishes to become pregnant, who do we refer them to?
Specialist
If an epileptic woman experiences seizures during pregnancy, what else could be the cause?
Eclampsia
Routine injection of which drug minimises the risk of neonatal haemorrhage associated with anti-epileptics?
Vitamin K
Which register should all pregnant women with epilepsy be encouraged to notify?
The UK epilepsy and pregnancy register
What should a breastfed infant be monitored for? (4)
- Sedation
2, Feeding difficulties - Weight gain
- Developmental milestones
What is an option for breastfed infants unable to tolerate mother taking anti-epileptics?
Formula - breastmilk must be weaned off to avoid withdrawal
What are the first line options for focal seizures? (2)
- Carbamazepine
2. Lamotrigine
What is the first line treatment option for generalised tonic-clonic seizures?
- Sodium Valproate
In which population is sodium valproate contra-indicated?
Women of childbearing age
What is an alternative to sodium valproate in generalised tonic-clonic seizures?
Lamotrigine
As well a sodium valproate and lamotrgine, which other drugs can also be considered in generalised tonic-clonic seizures? (2)
- Carbamazepine
2. Oxacrbazepine
What are the first line options for absence seizures? (2)
- Ethosuximide
2. Sodium Valproate
As well as ethosuximide and sodium valproate, which other drug is a suitable alternative for absence seizures?
Lamotrigine
What is the drug of choice for newly diagnosed myoclonic seizures?
Sodium valproate
What are the other options for newly diagnosed myoclonic seizures? (2)
- Topiramate
2. Levetiracetam
Usually seen in childhood, specific epilepsy syndromes, cerebral damage and mental retardation, what is the first line treatment option for atonic and tonic attacks?
Sodium Valproate
Which side effect is ethosuximide associated with?
Blood disorders
Due to its narrow therapeutic window, which anti-epileptic is started at a low dose and gradually titrated up?
Carbamazepine
As well as being used in focal seizures, which 2 anti-epileptics are now more associated with neuropathic pain?
1, Pregabalin
2. Gabapentin
As well as foal seizures and neuropathic pain, what else is pregabalin licensed for?
Generalised anxiety disorder
Which anti-epileptic is effective in migraine prophylaxis but is not licensed?
Gabapenint
Which anti-epileptic is a CD3?
Phenobarbital
What is special about the pharmacokinetics of phenytoin?
They are non-linear, a small increase in dose could result in a large increase in plasma concentration
What are the 3 main side effects of phenytoin?
- Liver toxicity
- Rash - discontinue if it occurs more than once
- Adolescents - coarsening face, acne, swelling gums
Which seizure type can pheytoin exacerbate? (2)
- Myoclonic
2. Absence
Phenytoin cannot be given via the intramuscular route. Which drug related to it can?
Fosphenytoin
Which side effect of Topiramate must be reported to a specialist?
Raised intra-occular pressure: glaucoma reported
What must be monitored if a patient is taking sodium valproate?
- LFTs
2. FBC
During the first 6 months of use, toxicity to which organ can occur with sodium valproate?
Liver
Sodium valproate should be withdrawn immediately if the patient experiences which side effects associated with hepatotoxicity?
- Persistent vomiting
- Abdominal pain
- Anorexia
- Jaundice
- Oedema
- Malaise
- Drowsiness
What is the risk of serious developmental disorders if infants are exposed to sodium valproate?
30-40%
What is the risk of congential malformations if infants are exposed to sodium valproate?
11%
Sodium valproate must not be used in females of child-bearing potential. If one has to take sodium valproate, what measures must she take?
Effective contraception, Pregnancy Prevention Programme
Before starting sodium valproate in a female of child-bearing age, what must be excluded?
Pregnancy
What are the precautions that must be taken if sodium valproate is to be used during pregnancy? (3)
- Lowest possible dose
- Divided doses
- Modified-release tablets
In status epilepticus, what is administered if seizures last longer than 5 minutes?
IV lorazepam, repeated once after 10mins if does not repond
In status epilepticus, what is the alternative to IV lorazapem if seizures last longer than 5 minutes? It is more unfavourable due to the risk of thrombophlebitis
IV diazepam
In status epilepticus, what is administered if seizures last longer than 25 minutes? (3)
- Phenytoin
- Fosphenytoin
3, Phenobarbital
In status epilepticus, what is administered if seizures last longer than 45 minutes?
Anaesthesia with midazolam or propofol
Why is intramuscular administration or using suppositories not recommended in status epilepticus?
Absorption from them is too slow
If alcohol abuse is suspected in a person having seizures, what must be considered?
Parenteral thiamine (B1)
As well as thiamine, deficiency of which vitamin B can also cause seizures?
Pyridoxine (B6)
If a patient experiences brief, febrile convulsions, what is the recommended treatment?
Anti-pyretic (e.g. Paracetamol)
Supplementation with which vitamin should be considered in patients taking certain anti-epileptics including Carbamazepine and Phenytoin
Vitamin D
Which disorders can carbamazepine cause, calling for its discontinuation?
- Blood
- Liver
- Skin
Which anti-epileptic can cause leucopenia?
Carbamazepine
Patients experiencing which side effects with carbamazepine should be offered modified release preparations? (5)
- Headache
- Ataxia
- Blurred vision
- Drowsiness
- Allergic skin reactions
What is the pre-treatment screening for carbamazepine due to the risk of Steven-Johnson Syndrom?
Test for HLA-B* allele in Chinese or Thai people -
What should the plasma concentration of carbamazepine be?
4-12 mg/L measured after 1-2 weeks
What is the NHS improvement patient safety alert associated with phenytoin?
Risk of death and severe harm resulting from error with injectible phenytoin
Is the use of intramuscular phenytoin recommended?
No, absorption is slow and erratic
As well as hepatoxicity, rash and effects on adolescents, what is a cardiac side effect of phenytoin?
Bradycardia and hypotension
What should the plasma concentration of phenytoin be?
10-20mg/L
What are the symptoms of phenytoin overdose? (6)
- Ataxia
- Slurred speeh
- Confusion
- Hyperglycaemia
- Nystagmus
- Diplopia