CNS: Epilepsy Flashcards
What is epilepsy?
A condition caused by a sudden surge of electrical activity of neurons, causing seizures
What is the first line treatment for all generalized seizures?
Sodium valproate
What is the most important factor to consider when choosing an appropriate antiepileptic?
The presenting epilepsy syndrome (or the seizure type if syndrome is unclear)
What influences the dosage frequency of most antiepileptics?
The plasma-drug half-life
What four antiepileptics have long half-lives, and therefore can be given once a day (at bedtime)?
Lamotrigine
Phenobarbital
Phenytoin
Perampanel
What are the two main types of seizure? How are they determined (2)?
Focal - affects one part of the brain
Generalised - affects both sides/multiple parts of the brain; symptoms affect whole body
What are four main types of generalised seizures?
Tonic-clonic
Absence
Myoclonic
Atonic and tonic
What are three main characteristics for tonic-clonic seizures?
Body stiffens
Followed by convulsions
Loss of bladder/bowel control
What can be used for tonic-clonic seizures when sodium valproate is inappropriate?
Lamotrigine
What type of seizure can lamotrigine exacerbate?
Myoclonic
What are three characteristics of an absence seizure?
Brief loss of consciousness
No convulsions
Common in children
What are the preferred drugs for monotherapy in absence seizures? (3)
Sodium valproate OR ethosuximide, alternatively lamotrigine
What are two characteristics of a myoclonic seizure?
Brief/short
Shock-like muscle jerks
What are the preferred drugs for monotherapy in myoclonic seizures? (3)
Sodium valproate
Alternatively, levetiracetam or topiramate
What are two characteristics of atonic/tonic seizures?
Brief loss of consciousness
Body sometimes falls to the ground as muscles are too weak to support it
What are the preferred drugs for monotherapy in atonic/tonic seizures? (3)
Sodium valproate (lamotrigine can be used as adjunct therapy) Alternatively, rufinamide or topiramate
What are the preferred drugs for monotherapy of focal seizures?
Remember: fo-CA-L
Carbamazepine or lamotrigine
Alternatively, levetiracetam, oxcarbazepine or sodium valproate
What did the MHRA conclude about switching between brands for antiepileptics?
Some antiepileptics need to be prescribed by brand as switching can cause loss of seizure control
What are four examples of category 1 antiepileptics?
Carbamazepine
Phenobarbital
Phenytoin
Primidone
What are four examples of category 2 antiepileptics?
Topiramate
Lamotrigine
Sodium valproate
Clonazepam
What are four examples of category 3 antiepileptics?
Levetiracetam
Gabapentin
Pregabalin
Ethosuximide
How should antiepileptics be withdrawn/switched? (3)
Slowly/gradually
One at a time
Under specialist supervision
What should a driver do if they get a seizure?
Stop driving and tell the DVLA ASAP
How long before someone who has had their first seizure can drive again?
6 months
What two criteria need to be met before patients with established epilepsy can drive?
Seizure free for a year
No history of unprovoked seizures
How long do patients who have had a seizure while asleep have to wait before driving again? What are the two exclusion criteria?
1 year, unless:
an pattern of no seizures while awake for a year after the first sleep seizure has been established;
there haven’t been any seizures while awake for three years (if they previously had seizures while awake)
How long do patients who have recently changed/withdrawn their antiepileptics wait before driving again?
6 months
When can sodium valproate be used in females? (2)
They satisfy the criteria for the Pregnancy Prevention Programme
There are no other appropriate alternatives
What two antiepileptics are safe in pregnancy?
Levetiracetam
Lamotrigine
What is a side effect of topiramate in pregnancy?
The baby may develop a cleft palate
What should be given to babies shortly after birth if their mum was on antiepileptics? Why?
Vitamin K, to reduce the likelihood of neonatal hemorrhage
What should happen if a lady on antiepileptics becomes pregnant unexpectedly?
No changes to their meds should be made (the risk of seizures > the risk of continued therapy)
If a patient on antiepileptics is planning to get pregnant, what supplement should she be offered?
Folic acid
What two antiepileptics are more likely to cause withdrawal symptoms in newborns?
Benzodiazepines and phenobarbital
What three antiepileptics are associated with risk of drowsiness in breast-fed babies?
Primidone
Phenobarbital
Benzodiazepines
What should infants be monitored for if their mother is on antiepileptics? (4)
Sedation
Weight gain
Developmental milestones
Feeding difficulties
Which antiepileptic can reduce the efficacy of hormonal contraception?
Carbamazepine
What are three common symptoms of antiepileptic hypersensitivity syndrome?
Rash
Fever
Lymphadenopathy
What drugs are associated with antiepileptic hypersensitivity syndrome? (5)
Carbamazepine Phenytoin Phenobarbital Primidone Lamotrigine
When is antiepileptic hypersensitivity syndrome most likely to occur? What should happen if it’s suspected?
Within the first 8 weeks of treatment; discontinue drug immediately
What did the MHRA concluded about all antiepileptics? What should patients do if they experience it?
There is a small risk of suicidal ideation - patients should report any changes in mood or distressing thoughts
Which antiepileptic is most likely to cause serious skin reactions (e.g. SJS, toxic epidermal necrolysis)? What can increase the risk of developing this?
Lamotrigine; concomitant use with sodium valproate
What drugs are most likely to cause blood dyscrasias?
Remember: C VET PLZ
Carbamazepine Sodium valproate Ethosuximide Topiramate Phenytoin Lamotrigine Zonisamide
Which antiepileptics are most likely to cause visual issues? (2)
Vigabatrin
Topiramate
Which antiepileptic is most likely to cause encephalopathic symptoms? What should be done if the patient experiences them?
Vigabatrin - reduce dose or withdraw
What did the MHRA conclude about gabapentin? Which groups of patients are more prone to experiencing it? (4)
Can cause severe respiratory depression - esp. if patients have existing respiratory issues; are old; have renal impairment; or are on other CNS depressants
Which antiepileptics are enzyme inducers, and can decrease the plasma conc. of other drugs? (3)
Carbamazepine
Phenytoin
Phenobarbital
Which antiepileptic is an enzyme inhibitor, and can increase the plasma conc. of other drugs?
Sodium valproate
What is status epilepticus?
A medical emergency where seizures last for more than 30 mins, or there are several seizures without regained consciousness in-between
What should be administered if a patient experiences convulsive status epilepticus?
IV lorazepam
What should be administered if a patient experiences non-convulsive status epilepticus, with signs of awareness?
Their usual antiepileptic drug
What should be administered if a patient experiences non-convulsive status epilepticus, with loss of awareness OR failure to respond to their normal antiepileptic?
IV lorazepam
What should be administered if a patient experiences febrile convulsions for less than 5 mins?
An antipyretic i.e. paracetamol
What should be administered if a patient experiences febrile convulsions for longer than 5 mins?
IV lorazepam
