NERVOUS SYSTEM - EPILEPSY Flashcards
what is epilepsy?
Seizure caused by hyper-excitable neurones firing AP.
What are the 3 types of seizures?
Focal
Generalised
Absence
What is 1st line drug treatment for focal seizures? (2 options)
Lamotrigine
Levetiracetam
Who is sodium valproate used in?
Patients who cannot have children
What are the 3 types of generalised seizures?
Tonic clonic
Myoclonic
Atonic, tonic
What is 1st line drug treatment for generalised seizures?
Sodium valproate
What is an absence seizure?
Last just a few seconds, and are characterized by a blank or “absent” stare.
What is 1st line drug treatment for absence seizures?
Ethosuximide
OR sodium valproate
What is a focal seizure?
Focal onset seizures start in ONE area and can spread ACROSS the brain and cause mild or severe symptoms
What is a generalised seizure?
Generalised seizures start as focal seizures that spread to BOTH sides of the brain.
What is MHRA 2017 warning regarding anti-epileptic switching?
Potential harm arising from switching of anti-epileptic brands.
Caused worsening SE + loss of seizure control
What is category 1 epilepsy medication?
Ensure the person is maintained on a specific manufacturer’s product.
List the 4 Category 1 epileptic drugs?
Carbamazepine
Phenytoin
Primidone
Phenobarbital
Phenytoin and methotrexate interaction?
Blood disorders
What are category 2 epilepsy medications? (TLCV)
Topiramate
Lamotrigine
Clonazepam
Valproate
What should we do if we need to switch category 2 anti-epileptics?
use clinical judgement and discuss seizure frequency and treatment history with the person and/or carer
What are Category 3 epileptic drugs? (LEGP)
Levitiracetam
Ethosuximide
Gabapentin
Pregabalin
Do we need to maintain same brand of category 3 epileptic drugs?
No need unless patient anxiety, risk of confusion or dosing errors
When do we keep patient on same cat 3 epileptic drug ?
If pt has anxiety, risk of confusion or dosing errors
What is Antiepileptic hypersensitivity syndrome?
Rare- dangerous
allergic reaction to some anti-epileptic drugs.
What to do if patient has Antiepileptic hypersensitivity syndrome?
Stop treatment
When does anti-epileptic hypersensitivity syndrome symptoms start?
Symptoms usually start between 1 to 8 weeks of exposure.
What 3 symptoms are common in antiepileptic hypersensitivity syndrome?
fever, rash, and lymphadenopathy
When can a decision be made about withdrawing anti-epileptic medicines?
Decision to withdraw antiepileptic drugs from a seizure-free patient MAY be considered after the patient has been seizure-free for at least two years
What 2 anti-epileptic classes are withdrawal dangerous in as it can cause rebound seizures?
barbiturates and benzodiazepines
What can abruptly stopping anti-epileptic medications do?
Cause rebound seizures
When does a patient STOP driving after having seizure?
If driver has a seizure (of any type) they must stop driving NOW + inform the (DVLA).
What 4 requirements must patients meet in order to start driving with established epilepsy?
No unprovoked seizures for 1 year
Seizure free
Seizure pattern + no effect on consciousness.
must NOT have a history of unprovoked seizures.
Patients who have had a 1st unprovoked epileptic seizure or a single isolated seizure CANNOT DRIVE for how many months?
6 months
Can patients who have had seizure in sleep drive?
NOT permitted to drive for 1 year from the date of each seizure unless they meet 2 criteria.
How long can someone drive after established epilepsy?
may drive a motor vehicle provided they are not a danger.
Patients must be seizure-free for at least one year
What are the 2 exceptions for patients with sleep seizures being able to drive?
Pattern of sleep seizures occurring only ever while asleep 1 year from first sleep seizure.
Established pattern of purely asleep seizures can be demonstrated over the course of 3 years if the patient has previously had seizures whilst awake.
What does the dvla recommend about driving after medication changes or withdrawal of antiepileptic drugs
no driving for at least 6 months from last dose
If a seizure happens due to medication withdrawal or change in medication, how long is license revoked for?
1 year - can be given after 6 months if treatment resumed + no seizures.
What is dosing frequency for anti-epileptic drugs?
twice daily
What are 2 carbamazepine derivatives?
Oxcarbazepine
Eslicarbazepine
What is 1 MAJOR risk of using gabapentin?
Severe respiratory depression
What specific indication is gabapentin also used for aside from epilepsy?
Neuropathic pain
What side effect is specific to lamotrigine use?
Severe skin reactions
What 2 skin reactions have developed due to use of lamotrigine?
Stevens-Johnson syndrome (SJS)
toxic epidermal necrolysis (TEN)
When is it better to take lamotrigine and why?
Night as can make you tired
What is the prodrug of phenytoin called?
Fosphenytoin
What anti-epileptic drug is most teratogenic?
Sodium valproate
What is 1 specific side effect of topiramate?
Eye disorders/ cleft palate
What is 2 specific rare SEs of vigabatrin?
Encephalopathy
eye disorders/ Visual field defect
What is the name of a carbonic anhydrase inhibitor which is also used for epilepsy?
acetazolamide
What is an example of a barbituate?
Phenobarbital
What is primidone metabolised into?
partially metabolised to phenobarbital
List 5 benzodiazepines used in epilepsy?
Cabazam
Clonazepman
Diazepam
Lorazepam
Midazolam
What is a key MHRA warning about anti-epileptic drugs?
Teratogenic
What 4 anti-epileptic drugs have increasing teratogenicity?
Carbamazepine
Phenytoin
Phenobarbital
Pregabalin
What do patients need when taking teratogenic drugs?
Highly effective contraception
What do do is patient planning to be pregnant and on epileptic drug?
Do not stop drug.
Urgent referral to specialist + give folic acid.
Join Uk epilepsy/ pregnancy register
What 3 drugs is teratogenicity dose dependent? (CPT)
carbamazepine, phenobarbital, and topiramate
What injection minimises the risk of neonatal haemorrhage at birth?
Vitamin K
Who should be encouraged to join the UK Epilepsy and Pregnancy Register?
Any pregnant female with epilepsy who are and are not taking meds
What is given to reduce the risk of neural tube defects in pregnancy?
Folate supplements given especially in 1st trimester
Can women breastfeed if on epileptic drugs?
If females taking monotherapy, they can.
If a female is on combination therapy or other risk factors= close monitoring is recommended
What 4 anti-epileptic drugs present in breastmilk? (ZELP)
zonisamide
Ethosuximide
Lamotrigine
Primidone
What 2 anti-epileptic drugs if slow metabolism in infant can cause drug buildup?
phenobarbital + lamotrigine
When is breastfeeding encouraged in epileptic patients?
When patient on monotherapy
What is 1 particular side effect of Zonisamide?
Over heating - makes you sweat less
What 4 things should breast-fed infants be monitored for if mum taking anti-epileptic?
drowsiness + feeding difficulties, adequate weight gain, and developmental milestones
What 3 drugs/classes cause drowsiness in breast fed babies?
Primidone
Phenobarbital
Benzodiazepines
What are 3 2nd line monotherapy drug treatment options for focal seizures?
Carbamazepine
Oxcarbazepine,
Zonisamide
what are 2 unlicensed drug alternatives for generalised tonic-clonic seizures?
Lamotrigine or levetiracetam
What are 4 side effects of anti-epileptic drugs?
Sedations + dizziness
Anti-epileptic hypersensitivity syndrome
Suicidal behaviour
Blood dyscrasias
vit D deficiency
What is Blood dyscrasias?
blood disorder- imbalance of four body fluids: blood, bile, lymph, and phlegm.
What counselling can be given for patients with Anti-epileptic hypersensitivity syndrome?
report any fever, rash of swollen lymph nodes
What is there an increased risk of with anti-epileptic drugs?
Suicidal behaviour- report mood change/ suicidal thoughts
What patient counselling to give for blood dyscrasias?
Report signs of infection or blood disorders.
e.g. fever, sore throat, mouth ulcer
What are 3 high risk examples of respiratory depression + should be aware of before giving gabapentin?
pts on CNS depressants (e.g. opioids, Benzos, barbiturate)
Pt with respiratory disease
Elderly/ Neurological disease + Renal impairment
What class of anti-epileptic drugs can cause severe respiratory depression?
Barbiturate
What are 3 MHRA warnings about gabapentin?
- severe respiratory depression
- Abuse + dependence
- suicidal thoughts
What drug class interacts with gabapentin to be fatal?
CNS depressants e.g. alcohol
What class drug is gabapentin + does it require safe custody requirements?
Class C controlled substance and is now a Schedule 3 drug,
is EXEMPT from safe custody requirements.
What is a risk of gabapentin use + what should healthcare professionals do before giving it?
risk of abuse + dependence
Do history of drug abuse before giving + observe for signs
What is a new MHRA warning of topiramate + counselling?
Increased risk of neurodevelopmental disabilities
Pts need contraception
What happens to sodium valproate during interaction?
Increased toxicity
Alcohol + sodium valproate interaction?
Increased risk of hepatotoxicity
Sodium valproate + azetazalomide interaction?
Increases the risk of toxicity when given with Valproate.
Monitor
Cannabidiol + sodium valproate interaction?
Cannabidiol increases the risk of increased ALT concentrations when given with Valproate.
Manufacturer advises avoid or adjust dose.
Sodium valproate + LMWH interaction?
Increases hepatoxicity
Lamotrigine + valproate interaction?
valproate increases lamotrigine exposure.
Adjust lamotrigine dose , monitor rash
Meropenem + sodium valproate interaction?
Meropenem decreases the concentration of Valproate. Manufacturer advises avoid.
What 2 drugs reduce drug levels of carbamazepine, phenytoin + phernobarbital?
Oestrogren/ progesterogen
Warfarin
What is phenytoin moa?
Reduces cortical neuronal excitability
Blocks Voltage gated Na+ channels
Prevent seizures
What is indication of phenytoin?
Focal + tonic clonic seizures
What is phenytoin therapeutic index?
10-20mg/L (40-80micromoles/L)
What is the relationship between phenytoin dose and plasma-drug concentration?
Non linear
What does non-linear plasma-drug concentration mean?
Small changes in dose = large changes in plasma concentration causing toxicity
what happens to phenytoin protein binding?
Reduced protein binding so more drug in blood
Why is plasma- phenytoin concentrations reduced in first 3 months of life
Reduced protein binding.
What is optimum trough plasma concentration of phenytoin in neonate to 3 months old?
6–15 mg/litre (25–60 micromol/ litre)
What should be monitored in IV phenytoin use?
Monitor ECG + blood pressure.
In what 3 instances is there higher phenytoin levels in blood due to less protein binding?
Pregnancy
If <3Months old
Elderly
What are 5 signs of phenytoin toxicity? (HANDS)
HypERglycaemia
Ataxia
Nystagmus
Diplopia
Slurred speech + confusion
What is ataxia?
Co-ordination, balance + speech
What is nystagmus?
eye rolling
What is diplopia?
Double vision
What deficiency can cause diplopia?
Low vitamin D
100mg phenytoin sodium is equivalent to —- phenytoin base?
92mg
What are 3 SEs of phenytoin that affects appearance?
couse facial hair, acne, gingival hyperplasia
What are 3 other SE of phenytoin?
Skin rashes
Blood dycrasias - monitor FBC
Bone disorders - caution if immobile, no sun exposure + low calcium
What 2 drug classes increase phenytoin levels + cause toxicity?
NSAIDs + Warfarin
What other 9 enzyme inhibitors cause increased toxicity of phenytoin?
Amiodarone
Azoles
Cimetidine
Erythromycin
Isoniazid
Metronidazole
CCB rate limiting
SSRIs
Valproate
What 2 anti-epileptic drugs reduce phenytoin levels?
Carbamazepine
Phenobarbital
What 2 drugs (enzyme inducers) reduce phenytoin levels?
Rifampicin
St john’s wort
Phenytoin is an enzyme ——?
Inducer = increases breakdown of the drug + lowers drug
What happens to oestrogen + progestogen with phenytoin?
Reduced efficacy
What schedule 3 drug lowers seizure threshold with phenytoin?
Tramadol
What 5 drug classes reduce anti-convulsant effect with phenytoin?
Anti-psychotics
Quinolone
SSRI
TCA
tramadol
What is MOA of carbamazepine?
Reduces cortical neuronal excitability
Blocks Voltage gated Na+ channels
Prevent seizures
What is indication of carbamazepine?
Focal + tonic- clonic seizures
What is therapeutic index of carbamazepine?
4-12mg/L
How do we monitor therapeutic drug monitoring?
measure plasma conc. after 1-2 weeks
What are 7 signs of carbamazepine toxicity? (HANDBAG)
HypOnatraemia - hallucination
Ataxia + anuria
Nystagmus
Drowsy, dizzy , slurred speech
Blurred vision
Arrhythmia
Gastro effect - N + V
what is a SE of carbamazepine in patient with RI?
Anuria - kidney cannot produce urine
What are 2 specific side effects of carbamazepine?
hepatotoxicity
HypOnatraemia
What to monitor if patient is hepatotoxic?
Monitor LFT
Symptoms such as vomiting, abdominal pain, dark urine, jaundice
What are some of the dose- related SE linked to carbamazepine?
Headache,
ataxia
drowsiness
N +V
Blurred vision
Dizziness
Allergic skin reactions
What preparations can be used to reduce dose-limiting SE of carbamazepine?
MR prep.
What 7 enzyme inhibitors increase carbamazepine levels?
Azole anti-fungals
Cimetidine
Macrolides
Rate limiting CCB
SSRIs- fluoxetine + Fluvoxamine
Grapefruit juice
Isoniazid
What 3 drugs reduce carbamazepine levels?
Phenobarbital + phenytoin
St john’s wort
Carbamazepine is an enzyme ——?
inducer
What 4 drugs increase hypOnatremia with carbamazepine?
Antidepressants (SSRI, TCA + MAOI)
Desmopressin
Diuretics
NSAID
What 8 drugs increase hepatoxicity with carbamazepine?
Co-amoxiclav
Flucloaxcillin
Tetracycline
Fluconazole
Isoniazid
MTX
Statin
Sulfasalazine
What drug increases blood dyscrasias with carbamazepine?
Clozapine
Carbamazepine + MTX interaction?
increased hepatotoxicity
What is MOA of Sodium valproate?
reduces cortical neuronal excitability, blocks Na+ channels
Increases GABA levels
What is indication for Sodium valproate?
Epilepsy (generalised)
Mania + migraine prophylaxis
What to do if planning pregnancy + taking sodium valproate?
Contact GP/ specialist
What is interaction between ertapenem + sodium valproate?
Ertapenem decreases the concentration of Valproate.
Manufacturer advises avoid.
What 3 things are needed to be given when giving patient sodium valproate?
Patient guide
Patient care
ARAF
What forms of contraception needed for females when taking sodium valproate?
1 user independent = IUD, implant
2 x user dependent - pill + barrier
What 3 criteria must women meet to on pregnancy prevention programme?
For females of child-bearing potential
No other treatment for them
Specialist initiation
What are 4 SE of sodium valproate?
Blood dyscrasias
Bone disorders
Hepatotoxicity
Pancreatitis
What 2 things should pharmacists do when supplying sodium valproate?
Patient card
Give whole pack - warning label + PIL
(remind of risk + review)
What counselling to give patients suspecting pancreatitis on valproate?
Report signs- abdo pain , N +V
Sodium valproate is an enzyme —-?
Inhibitor - increases drug levels
What 5 drugs decrease anticoagulant effect to cause more bleeding?
Anti-psychotic
Quinolone
SSRI
TCA
Tramadol
What is status epilepticus?
dangerous condition
Fits follow one another without recovery of consciousness between them.
Convulsive for > 5 mins
What to give for status epilepticus if resus facilities are available?
IV lorazepam
Who to call after 1st dose of benzo for status epilepticus?
emergency services
For status epilepticus, if there is NO response to 2 doses of a benzodiazepine, what to give?
Levetiracetam, phenytoin or valproate
If fails:
Phenobarbital or general anaesthesia
What is 1st line tx for status epilepticus in community?
diazepam (rectal)
Midazolam (oromucosal)
Repeat once after 5-10 mins if needed
What to give if alcohol abuse causing status epilepticus?
Also give Parenteral thiamine
Lennox-Gastaut syndrome 1st line tx?
Sodium valproate
Atonic or tonic seizures 1st line tx in males or females unable to have children?
Sodium valproate
Atonic or tonic seizures 1st line tx in females who can have children?
Lamotrigine
What are Myoclonic seizures?
sharp, uncontrollable muscle movements.
What to give for cluster seizures?
clobazam or midazolam
Which 8 antiepileptics are more prone to Antiepileptic hypersensitivity syndrome?
carbamazepine, lacosamide, lamotrigine, oxcarbazepine, phenobarbital, phenytoin, primidone, and rufinamide
When can withdrawal of epilepsy meds be considered?
patient has been seizure-free for at least two years
What to give patients if sodium valproate not successful in myoclonic seizures?
levetiracetam
What 7 epilepsy drugs are known for causing blood disorders? (C.VET.PLZ)
Carbamazepine
valproate
ethuximide
topiramate
Phenytoin
Lamotrigine
Zonasamide
What to do if patient on phenytoin has rash?
STOP
What does MHRA recommend giving with valproate if immobile for long time or inadequate calcium?
vitamin D supplementation
Which 4 anti epileptics are long acting so can be given OD at bedtime?
Lamotrigine
Perampanel
Phenobarbital
Phenytoin
How long to continue contraceptives after finishing sodium valproate?
At least 3 months after stopping