Nervous System Flashcards
How are cognitive symptoms (memory impairment, confusion) in dementia caused by Alzheimer’s disease managed?
Give the classes of drugs and examples.
Acetylcholinesterase inhibitors- donepezil, galantamine, rivastigmine.
MDMA receptor antagonist - memantine- max 20mg OD (note this is first line in severe Alzheimers)
How are non-cognitive symptoms (delusions, anxiety, aggression) managed?
Antipsychotics
Acetylcholinesterase inhibitors or memantine
What is a specific MHRA advice in elderly patients with dementia?
Increased risk of stroke, TIA and death when antipsychotics are used in elderly patients with dementia.
What is a specific side effect of galantamine?
Serious skin reactions including Stevens - Johnsons syndrome. STOP if rash occurs.
Which anti-epileptics are Category 1 meaning patients should be maintained on a specific brand?
CPPP
carbamazepine
phenytoin
phenobarbital
primidone
Which anti-epileptics are Category 2 meaning patients may be need to be maintained on a specific brand?
valproate, lamotrigine, clobazam clonazepam, topiramate, oxcarbazepine,
Which anti-epileptics do not need to be prescribed by brand?
levetiracetam, gabapentin, pregabalin, ethosuximide.
Which drugs lower seizure threshold?
tramadol quinolone- e.g ciprofloxacin carbapenems SSRIs TCAs clozapine
What is antiepileptic hypersensitivity syndrome and which anti-epileptics can cause it?
Rare but fatal reaction to an antiepileptic- rash, fever, organ failure.
Can be caused by: CPPP (carbamazepine, phenytoin, phenobarbital, primidone) lacosamine, lamotrigine, oxcarbazepine
How long must you wait to drive after a single isolated seizure (or after a dose change) ?
6 months
5 years if bus/ lorry driver
How long must you wait to drive after a diagnosis of established epilepsy?
1 year seizure free
10 years if bus/lorry driver
How long must you wait to drive if you get sleep seizures?
1 year seizure free
1 year if seizures only ever occur at night
3 years if seizures now occur at night only but have previously had awake seizures.
What should a woman who is taking anti-epileptic medication do if she becomes pregnant?
Do not stop taking meds as seizure harmful to foetus- see specialist.
Reassure them there is still 90% chance of a child with no malformations.
They should notify the UK epilepsy and pregnancy register.
Routine vitamin K injections at birth reduce risk of neonatal bleeding.
Which antiepileptics most readily transfer into breastmilk?
ZELP
zonasimide
ethosuximide
lamotrigine
primidone
Which anti-epileptics cause established drowsiness to a breast-fed infant and are also most likely to accumulate and cause withdrawal in the infant?
LPP
lamotrigine
phenobarbital
primidone
benzodiazepines.
What anti-epileptic is first line for all seizure types except focal where its second line?
What is first line in focal seizures?
What is a common second line option for most seizures?
Sodium valproate
First line for focal seizures- Carbamazepine/ lamotrigine.
Lamotrigine. Carbamazepine (if focal/tonic clonic)
In what type of seizures are CPPGTV (carbamazepine, phenytoin, pregabalin, gabapentin, tiagabine, vigabatrin) not recommended?
Absence, myoclonic, atonic and tonic seizures.
They can only be used for focal and tonic- clonic.
What is important before starting carbamazepine and related anti-epileptics and phenytoin therapy?
Screen Hans Chinese or Thai patients for HLA-B1502 allele. If the patient dose have this allele, avoid the drug as these patients are at a higher risk of Stevens- Johnsons syndrome.
What are some important side effects of carbamazepine?
What supplementation may patients on this drug need?
Blood disorders -requires withdrawal
Hepatic disorders
Skin disorders
Vitamin D if immobile or inadequate sun time or if low dietary calcium.
What is the MHRA alert associated with gabapentin?
Rare risk of severe respiratory depression
What can occur in patients with low body weight (<50kg) receiving high doses of gabapentin liquid (Rosemont)?
Levels of propylene glycol and saccharin (excipients in the liquid) that exceed WHO RDI.
What drug can increase plasma levels of lamotrigine and requires use of reduced lamotrigine doses?
Valproate
What is the target plasma concentration of phenytoin?
10-20mg/L
What are some side effects of phenytoin?
Are there any specific cautions?
Rash - STOP drug serious skin reactions blood disorders With IV use: hypotension and bradycardia Vitamin D deficiency- may need supplementation.
Enteral feeding- interrupt feeding 2 hours before and after dose.
Whats is a notable side effect of topiramate that requires treatment cessation?
Occular issues- myopia (near-sighted), glaucoma, raised intraoccular pressure.
What is a potential side effect of zonasimide?
Overheating and dehydration in children.
AVOID things that will cause overheating such as exercise.
Which anti-epileptic is contraindicated in visual field defects?
Vigabatrin
What is the MHRA alert regarding sodium valproate?
Contraindicated in women of childbearing age. Only to be used if conditions of PPP (pregnancy prevention programme) are met and ONLY for EPILEPSY when there are no other options
PPP
- Given patient guide, review by specialist with last year, on highly effective contraception.
- Annual review with specialist- complete and sign risk acknowledgement form
- Pharmacists must dispense whole packs where possible, warning label (or sticker) on all containers, discuss risks each time a prescription is collected.
How is status epileptics managed?
Seizures > 5minutes
IV lorazepam. can be repeated after 10 minutes
IV diazepam ( VTE risk if given IV- less with emulsion)
Midazolam (buccal) or diazepam rectal solution (NOT - IM/ suppositories absorption too slow!)
If alcohol excesss suspected give pabrinex
Seizures lasting > 25 minutes
(fos) phenytoin or phenobarbital (NOT IM)
Seizures lasting >45 minutes
anaesthesia with thiopental, midazolam, propofol.
Patient will need full ITU support.
How are febrile convulsions managed
Paracetamol but if it lasts > 5 mins, treat as status epilepticus.
How is ADHD managed?
First line- methylphenidate
Second line- dexamphetamine or atomoxetine
Third line- lisdexamphetamine guanfacine
Beware: risk of suicidal thoughts with these meds
How long should treatment for bipolar continue?
2 years from last manic episode.
5 years if at risk of relapse.
How is mania managed? Acutely and long term.
Benzodiazepines in initial stages
Antipsychotics: olanzapine/ quetiapine/risperidone
Long term management: lithium/ valproate/olanzapine.
Carbamazepine is useful in rapid cycling bipolar.
What do you know about lithium?
Cover levels, pre/post dose levels, monitoring, side effects, toxicity.
Levels- 0.4-1mmol/L (narrow therapeutic index)
Samples 12 hours post dose
Levels weekly at first then every 3 months
Every 6 months- TFTs, FBC, U+Es, BMI
Withdraw drug over at least 4 weeks- 3 months ideal
Long term use- thyroid disorders, nephropathy, weight gain, abdominal issues.
Toxicity- N+V, diarrhoea, coma, confusion, tremor
What do you know about SSRIs?
Include side effects and max doses.
First choice in patients with UA or recent MI is sertraline.
contraindicated in poorly controlled epilepsy
Initiate doses slowly and withdraw slowly (4 weeks)
Side effects- BADSSRI
body weight increase, anxiety, dizziness, sedation, suicidal thoughts, reproductive dysfunction, insomnia, bleeding disorders, cardiac disease (arrhythmias), QT prolongation,
Hyponatraemia- especially in the elderly
Max doses- citalopram 40mg, fluoxetine 60mg, sertraline 200mg OD
How long should antidepressants be continued after remission?
6 months
12 months if elderly or if using for generalised anxiety disorder.
2 years if recurrent depression.
What is a common side effect of all antidepressants
Suicidal thoughts especially with those with a history of these thoughts and children + young adults.
How is anxiety disorder managed?
Acutely: a benzo or buspirone
Chronic anxiety (> 4 weeks): antidepressants GAD : SSSRI, SNRI or pregabalin
How are panic disorder, OCD, PTSD and social anxiety disorder managed?
SSRI first line for all of them
Clomipramine is second line for panic disorder and OCD
Moclobemide is licensed for social anxiety disorder
Which are the sedating and which are the less sedating tricyclic antidepressants?
when would each be preferred?
Sedating- amitriptyline and dosulepin
Preferred in agitated patients
Less sedating- nortriptyline, lofepramine.
Preferred in withdrawn (flat) patients
What do you know about TCAs?
Overdose is dangerous- high fatality- cardiotoxicity especially with amitriptyline + dosulepin.
Signs of overdose- mydriasis (dilated pupils, coma etc)
Cause antimuscarinic side effects, arrhythmia, hyponatraemia.
Can cause withdrawal- start and taper gradually
What do you know about monoamine oxidase inhibitors?
Include examples, Interactions, side effects
- examples- isocarboxazid, phenelzine, moclobemide.
- Many dangerous food and drug interactions.
- Risk of interaction persists for 2 weeks after stopping.
- Hypertensive crisis can occur if given with tyramine rich foods (fermented foods- cheese, beer, salami) and alcohol.
- They can cause postural hypo/hypertension (tranylcypromine is the worst)
- They cause hepatotoxicity
- Can cause withdrawal- start and taper gradually
What should be done when starting/ stopping a MAOI?
Other antidepressants should only be stated after 2 WEEKS (3 weeks if starting clomipramine/ imipramine)
An MAOI should not be started until:
2 WEEKS after a previous MAOI is stopped
1 WEEK after stopping SSRI (5 weeks for fluoxetine)
1-2 WEEKs after TCA (3 weeks if clomip /imipramine)