Nervous System Flashcards
Which of the acetylcholinesterases used for dementia is also licensed for mild/moderate dementia associated with Parkinsons?
Rivastigmine
This has TWICE daily dosing!
When should donepezil be given?
Once daily (unlike the other acetylcholinesterases that are BD) Give at bedtime Usual dose 5-10mg
What conditions are cholinergic drugs (acetylcholinerase inhibitors used in dementia) cautioned in?
Asthma
Epilepsy/ history of seizures
Those with a slow pulse
History of gastric ulcers
What are the common side effects of the Acetylcholinersterase inhibitors used in dementia?
Diarrhoea and vomiting Dizziness Headache Hallucinations Anorexia (weight loss)
Name the 4 drugs used in dementia?
Donepezil
Galantamine
Rivastigmine
(above 3 are Acetylcholinesterase inhibitors)
Memantine (a NMDA receptor antagonist)
Which acetylcholinesterase inhibitor comes as a patch?
Rivastigmine
24 hour patch
Short acting benzodiazepines?
Midazolam
Used for epileptic seizures and febrile convulsions due to its fast onset to action
Triazolam
Intermediate acting benzo’s?
Clonazepam
Lorazepam
Oxazepam
Temazepam
Remember CLOT
(Hence why some of these are used for agitation in our patients: not too longer acting to make them too drowsy but act for long enough)
Long acting benzo’s?
Chlordiazepoxide
Diazepam
Alprazolam
Used as sedatives (diazepam for insomnia associated with anxiety) and used or ANXIETY
What is Buspirone?
A serotonin receptor agonist used for anxiety
Name some medication used in ADHD?
CNS Stimulants:
Dexamfetamine
Lisdexamfetamine (prodrug of dexamfetamine, Elvanse, Elvanse Adult)
Atomoxetine (POM)
Methylphenidate (Ritalin, Concerta, Medikinet, Equasym)
What are the common side effects of CNS stimulants used in ADHD? Remember a patient described it as being on ‘speed’
Sleep disturbance; take in morning or will keep patient awake! Irritability, aggression Diarrhoea, vomiting Nervousness Tachycardia (with methylphenidate) Headache
When should antidepressants be avoided in bipolar?
Rapid cycling bipolar
recent history of hypomania (mild form of mania, marked by elation and hyperactivity)
rapid mood fluctuations
This is because the antidepressant will increase manic symptoms so if their bipolar is more manic based then avoid!
What mood stabilisers do we see used in Bipolar disorder?
Carbamazepine
Valproate
Lithium
When should lithium be taken?
At night- blood test needs to be 12 hours post-dose and blood test usually in the morning
Lithium toxicity is made worse by sodium depletion, therefore what drugs should be avoided?
Concurrent use of diuretics, particularly thiazides.
Signs of lithium toxicity?
Vomiting and diarrhoea Coarse tremor (progressed from fine tremor) Visual disturbance, blurred vision Muscle weakness Confusion Restlessness HYPERNATREAMIA
Can lithium be used in pregnancy?
Avoid if possible, especially in first trimester
If used in 2nd and 3rd trimester- dose may need to be increased but put back down to normal once child born.
What are the two different Lithium salts?
Lithium Carbonate
Lithium Citrate
Brands of carbonate: Camcolit, priadel tablets
Brand of citrate: priadel liquid (citrate only comes as a liquid)
Why is it important to stick to the same brand of lithium?
Different preparations have different bioavailability
Changing the preparation would require the same precautions and monitoring as initiation of treatment!
Dexamfetamine and lisdexamfetamine are cautioned in those with Tics and Tourrettes
May also cause growth restriction in children
Patients and carers should be advised to monitor for suicidal ideation when taking this ADHD drug
Atomoxetine is a POM drug used for ADHD
This is also the case for Agomelatine, a drug with a similar name, a melatonin receptor agonist used for depression, can cause suicidal behaviour
Which antipsychotic drug should be handled with care?
Chlorpromazine
Causes contact sensitisation (irritates skin)
Hyponatreamia has been linked to all antidepressants, but is more likely with which class?
SSRIs
Suicidal behaviour, especially during the first 2 weeks, has been linked to antidepressant use
Serotonin syndrome also a risk, particularly with MAOIs
MAOIs can interact with a lot of drugs and this is a particular problem as they can still interact even when discontinued
Interactions can occur for up to 2 weeks after discontinuation due to long half life.
Which antidepressant can be hepatotoxic?
Agomelatine
LFTs need to be monitored regularly throughout
Which SSRIs is the risk of withdrawal syndrome highest? Why?
Paroxetine
Venlafaxine
Due to their shorter half lives
Bromocriptine, Cabergoline and Pergolide are all stimulants of dopamine receptors in the brain, used in Parkinson’s. There are some specific safety warnings associated with these
Fibrotic reactions
Impulse control disorders
Sudden onset of sleepiness: avoid driving
Hypotensive reactions during first few days of treatment
The latter 3 also apply to pramiprexole
Which antiemetic is associated with a small increased risk of cardiac effects?
Domperidone
Also Associated with QTc prolongation
Treatment should not exceed 1 week
What antiemetic is associated with an increased risk of neurological effects, such as tardive dyskinesia and EPSEs?
Metoclopramide
particularly in young adults (females aged 15-19)
Should not be routinely given to patients under 20/ 18 years old
Only for short term use (5 days)
Drug of choice for nausea associated with myocardial infarction. Avoid use in Parkinson’s
When used for migraine: treatment should not exceed 3 months due to risk of tardive dyskinesia
Fentanyl transdermal patches
Manufacturer advises use only in opioid tolerant patients due to risk of respiratory depression
What schedule is tramadol?
Schedule 3 CD No Reg Exempt from safe custody
Prescription requirements and 28 day validity still stand
Which anti epileptic should patients be warned to look out for signs of fever, rash, mouth ulcers, bruising, bleeding?
Carbamazepine
Signs of blood, hepatic or skin disorders
What has IV infusion of Fosphenytoin been associated with?
Severe cardiovascular reactions
What severe skin reaction has Lamotrigine been associated with?
Stevens Johnson syndrome
This is where cell death/ necrosis occurs causing the epidermis to separate from the dermis. Usually begins with fever, ulcers, sore throat
Which antieplieptic do we need to be careful with in liver impairment?
Sodium valproate
Monitor LFTs
Which antieplieptic is a TDM drug? What are the signs of toxicity?
Phenytoin
Signs: Nystagmus (involuntary eye movement) one of the first signs Slurred speech Uncontrolled movement (ataxia) Confusion Diplopia (double vision) HYPERGLYCAEMIA
Which antieplieptic could be a problem in patients with glaucoma?
Topiramate
Associated with acute myopia (short sightedness with secondary angle closure glaucoma
Which antieplieptic drug is associated with visual field defects?
Vigabatrin
Simple: visual = Vi
Which drug used to aid smoking cessation should be discontinued if the person becomes agitated, depressed or suicidal?
Varenicline
This is a selective nicotine receptor partial agonist
Which is stronger, methadone oral solution or linctus?
Oral solution (1mg/1ml) is 2.5 x stronger than the linctus!
Which antidepressants are safest in overdose?
SSRI’s
These should be considered FIRST LINE in treatment of depression.
Which antidepressant is safest to use in a patient with unstable angina/ had a recent Myocardial Infarction?
Sertraline (SSRI)
Why is St Johns Wort such a problematic drug?
Its an enzyme inducer so lots of interactions: decreasing concentrations of drugs metabolised by these
Also the amount of active ingredient changes between preparations so patient could suddenly show signs of toxicity if concentrations of an interacting drug increase.
Antidepressants can cause hyponatreamia. What are the symptoms of this?
Confusion
Drowsiness
Convulsions
What does management of anxiety usually involve?
A benzodiazepine or Buspirone
Chronic anxiety - antidepressant- usually an SSRI- usually escitalopram, paroxetine or sertraline
How do TCA’s work?
Block the reuptake of both noradrenaline and serotonin, although each to different extents.
Which TCA is frequently associated with hepatotoxicity?
Lofepramine
Which TCA should be initiated by a specialist?
Dosulepin
MAOI’s= PIT of despair
Phenelzine Isocarboxazid Tranylcypromine (all irreversible inhibition) MAOIs inhibit monoamineoxidase, therefore causing accumulation of amine neurotransmitters
Moclobemide= reversible inhibition of monoamine oxidase
For use on an emergency basis, the dose of an IM antipsychotic should be Lower or Higher than the corresponding oral dose?
Lower, due to absence of first pass metabolism with IM route
Are antipsychotics better at treating positive or negative symptoms?
Positive
Which antipsychotic can cause contact sensitisation so should be handled with care?
Chlorpromazine
Tablets should NOT BE CRUSHED
Which antipsychotics may need their dose adjusting according to smoking status during therapy?
Clozapine Haloperidol Chlorpromazine Olanzapine Remember CHOC - choc and smoking r bad 4 u Most marked with clozapine?