CNS Flashcards
What type of seizures are Carbamazepine, Oxcarbazepine, Zonisamide indicated for
Focal 2nd line
What are the first line anti seizure medicines if you are a woman of childbearing age?
Lamotrigine / Levetiracetam
What is the most effective and 1st line anti seizure medicine
Sodium valproate
Absence seizure 1st line
Ethosuximide
What are the treatment options for non-self-terminating status epilepticus
IV Lorazepam 1st
Buccal Midazolam
Rectal Diazepam
A patient taking carbamazepine 200mg tablets 2BD is nil by mouth what options do you have
Rectal carbamazepine
Increase dose by 25% to 1000mg rectally so 1x 250mg suppository QDS
Not ideal
NG tube crush and disperse
IV Levetiracetam conversion
What anti seizure medicines must a patient be maintained on the same brand?
Carbamazepine, Phenytoin, Phenobarbital, Primidone
Medicines that Lower the seizure threshold
Tramadol, Theophylline, Quinolones, Bupropion, beta Lactams, Metronidazole, Isoniazid, SSRIs, TCAs, MAOis
Lamotrigine side effect
Steven Johnson’s Syndrome
Which antiepileptics cause respiratory depression
Gabapentinoids
Which antiepileptic can cause hyponatraemia and oedema
Carbamazepine
Which anti seizure medicines induce hepatic enzymes?
Phenytoin, Phenobarbital, Carbamazepine
Which anti seizure medicines inhibit hepatic enzymes
Sodium Valproate
Carbamazepine target level
4-12mg/L
Carbamazepine toxicity signs
Hyponatraemia
Ataxia (slow movements)
Nystagmus (eye drift)
Drowsiness
Blurred vision
Arrhythmias
Gastro disturbances
Phenytoin target level
10-20mg/L
Which drug has the same target level as phenytoin and what is the level range?
Theophylline
10-20mg/L
Phenytoin toxicity
Slurred speech
Nystagmus (eye drift)
Ataxia (slow movements)
Confusion
Hyperglycaemia
Double vision
How does epilepsy affect driving
Once seizing must stop driving and inform DVLA
If 1st unprovoked or a single isolated seizure can drive after 6 months of no seizures
In established epilepsy 1 year seizure free warrants driving
If medication stopped no driving for 6months
What injection is given to children of epileptics at birth and why?
Vitamin K
Reduce risk of neonatal haemorrhage
What supplement is given during the first trimester and why
Folic acid
Prevent neural tube defects
Which antiepileptics are teratogenic
Valproate (PPP), Topiramate (PPP), Carbamazepine, Phenobarbital, Zonisamide, Phenytoin
Which antiepileptics are most present in breastmilk
Primidone, Ethosuximide, Lamotrigine, Zonisamide
What are the MHRA warnings shared between all antiepileptics
Suicidal ideation and behaviour
Only specialists should switch between agents/ brands
All are potentially teratogenic
Which anti seizure medicines require a pregnancy prevention plan
Valproate, Topiramate
Valproate MHRA alerts
PPP required
2 specialists must independently agree this is the only option to initiate
Annual consent of teratogenic risk form for female patients
Could affect male offspring
Must issue an alert card
Must prescribe and dispense full boxes only
Sodium valproate target level
50-100
Phenobarbital target level
15-40
When should levels be taken for antiepileptics
Pre dose trough
What is sodium valproate licensed to treat?
All forms of epilepsy, Mania,
Migraine prophylaxis unlicensed
Valproate toxicity
N&V, Abdo pain, Anorexia, Jaundice, Oedema (<Na+), Drowsiness, Seizures, Suicidal
Which antiepileptics affect the eyes
Vigabatrin reduces visual field
Topiramate causes glaucoma
How to treat an acute episode of mania
Stop antidepressant
Start Olanzapine or quetiapine or haloperidol or risperidone
If ineffective try another from above
If ineffective add lithium
If lithium not suitable use valproate
How are manic episodes prevented
1st Lithium
2nd valproate or carbamazepine
Lithium target levels
0.4-1
Lithium toxicity
They act drunk
N&V, blurred vision, tremor, drowsiness, polyuria, confusion, arrhythmia, thirst, reflexes, coordination and speech loss,
When should lithium levels be measured
12h post dose weekly in week 1
Then 3 monthly for year 1
Then 6 monthly
Apart from toxicity what else can lithium cause
+/-Thyroid, nephrotoxic, Rhabdomyolysis, QT prolongation, intracranial HTN, teratogenic in 1st trimester
When in combination with which drugs will lithium cause hyponatraemia
SSRIs, Diuretics, Carbamazepine
What electrolytes does lithium disturb
Sodium and potassium both lowered
What should you counsel Parkinson’s patients on regarding their treatment
Impulse control disorders
sudden onset sleep
Levodopa red urine
No tyramine foods if MAOBi
What antipsychotic is most associated with weight gain
Olanzapine and clozapine
Benefits of aripiprazole
Less extrapyramidal SEs
Reduces prolactin in hyperprolactinaemia
Less QT-prolongation
Least hyperglycaemic and weight gaining
When is clozapine licensed
When 2 other antipsychotics fail
Clozapine MHRA warnings
Fatal faecal impaction/intestinal obstruction/paralytic ileus must be on laxatives aiming 2-3 soft stools a day.
Level monitoring for agranulocytosis and toxicity especially if smoking is changed
When to take clozapine levels
Immediately pre-dose trough
If OD dosing 10-12h post dose
Weekly 1st 18w, q2w until 1st year done
Monthly thereafter and 1m after cessation
When must clozapine be retitrated
After 2 missed doses/ coming to 3rd dose
Clozapine target levels
0.35-5
Which antiepileptic causes gingivinal hyperplasia
Phenytoin
High risk drugs that cause serotonin syndrome
Lithium, methadone, linezolid, Tramadol, fentanyl, Triptans, prams, SNRIs, MAOi, St. John’s wort, amphetamines
What drugs should be avoided in sciatica
paracetamol monotherapy ineffective must be combined.
SSRI, SNRI, TCA, GABA, Antiepileptics
How is spasticity treated in multiple sclerosis?
Baclofen
How is fatigue managed in multiple sclerosis?
Amantadine
Drugs contraindicated in Myasthenia Gravis
Quinolones
Beta blockers
Aminoglycosides
Tetracyclines
Macrolides
Antimilarials
Neuro claps
Clozapine
Lithium
Antipsychotics
Phenytoin
Which antiemetics cause parkinsonisms
Metoclopramide
Prochlorperazine
Sedating antihistamines
Hydroxyzine, Promethazine, Cinnarizine, Diphenhydramine, Cyclizine, Buclizine, Chlorphenamine
Non-sedating antihistamines
Acrivastine, Cetirizine, Desloratadine, Loratadine, Fexofenadine
How can hypersensitivity reactions and Steven Johnson Syndrome be avoided in Lamotrigine?
Slowly uptitrate to an effective dose
What analgesic option is least appropriate for a patient taking lithium
NSAIDs
Triptans Contraindications
Elderly
HTN
prev stroke/ MI/ TIA
Vascular disease
Cautioned if seizure history
If an epileptic patient has compliance issues which AEP is a good option
Phenytoin has a long half life
Thiazide like diuretics in renal impairment
Ineffective below 30mL/min
Loop diuretics in renal impairment
High doses cause tinnitus and deafness but can be used
Potassium sparing diuretics in renal impairment
Avoid in AKI and SEV impairment <30mL/min
Which medicine is best for sedation in Parkinson’s
Risperidone least associated with hallucinations but still sedating
Which antipsychotic is least associated with hallucinations
Risperidone
Methylphenidate review
Appetite
HR
BP
Weight
Management of changing a gabapentinoid to another medicine compared to another gabapentinoid
Between no weaning required
Addictive creating dependence
How do Carbamazepine and Bendeoflumethiazide interact
Hyponatraemia
