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?
What class of antipsychotics are hepatotoxic and can therefore precipitate coma?
Phenothiazines
Chlorpromazine, Promazine, Pipotiazine, Fluphenazine, Trifluoperazine, flupentixol
What is the difference between haloperidol and haloperidol decanoate? Same with zuclopenthixol and zuclopentixol decanoate?
Decanoate is used for maintenance in schizophrenia only
Should NOT be used for short term management of an acute episode e.g. zuclopentixol acetate used for this (rapid tranq.)
What side effect can antiparkinsons drugs cause in the elderly?
Confusion
Which antimuscarinic, used for drug-induced parkinsons, should be taken with or after food?
Trihexyphenidyl hydrochloride
Which drug, used in parkinsons, can colour urine reddish-brown?
Entacapone
Which drug, used in parkinsons, should you avoid taking iron-containing products at the same time of day??
Entacapone, as it may form CHELATES WITH IRON, affecting its absorption
Which drug, used in parkinsons, should patients look out for signs of Hepatotoxicity (anorexia, nausea, vomiting, abdo pain, dark urine, pruritis)?
Tolcapone
A catechol-o-methyltransferase inhibitor
What is the anti-emetic of choice in parkinsons?
DOMPERIDONE
It does not cross the BBB
Which anti-emetics are of value in the treatment of nausea and vomiting associated with cytotoxic use in cancers?
ONDANSETRON
GRANISETRON
Also used in prevention of post-op nausea and vomiting
What is the most effective drug used in motion sickness?
Hyoscine Hydrobromide
Promethazine also used if sedative effect needed
Domperidone, metoclopramide are ineffective!
What condition are a lot of antihistamines cautioned in?
Epilepsy, glaucoma
How should vomiting in pregnancy be managed?
Morning sickness- anti-emetic not routinely recommended- home remedies such as ginger.
If severe: short term antihistamine e.g. promethazine
(metoclopramide alternative)
How is the pain from Mild Sickle-cell crisis managed? What if it is severe?
Just follow the pain ladder:
Mild= paracetamol, NSAID, codeine
Severe= Morphine, dihydromorphine
A patient on warfarin requests a pack of aspirin 300mg OTC to treat a headache. What do you do?
Increased risk of bleeds when aspiring given with coumarins due to its antiplatelet effect.
Also: Aspirin enhances anticoagulant effects of heparins
What is the max strength of codeine that you can buy OTC?
12.8mg
Present in Solpadeine Max and Panadol Ultra
What are the side effects of Morphine?
Nausea & Vomiting (most common) Drowsiness, Dizziness Constipation Headache Mild itching
Morphine is the opioid of choice for severe pain in palliative care. How often is it given?
Given every 4 hours
or 12 or 24 hours if its MR
How often should fentanyl transdermal patches be changed?
every 72 hours
Which analgesics have been associated with psychiatric reactions/ hallucinations?
Tramadol Pentazocine (avoid this after a myocardial infarction)
Opioids are cautioned in respiratory disease such as COPD and acute attacks of asthma
This is because of their potential to produce respiratory depression
Long term use of opioids can result in
Hypogonadism and adrenal insufficiency
Hyperalgesia: abnormal pain sensitivity
What is the dose of codeine in adults per day?
30-60mg every 4 hours PRN
MAX DOSE: 240mg per day (8 tablets- same as paracetamol!)
In children 12-17yrs: 30-60mg every 6 hours PRN, max 240mg
Codeine Max dose- adults
240mg per day (8 tablets- same as paracetamol!)
How old do you have to be to purchase codeine OTC? What age must children be to have codeine prescribed?
18 or over to purchase
Only for use in children over 12. 12-18 years: max dose 240mg daily (same as adults) at intervals no less than 6 hours.
Treatment should be limited to 3 days
The ability to metabolise codeine into morphine can vary greatly between individuals. Ultra rapid metabolisers are more susceptible to toxicity. What enzyme is involved?
CYP2D6
Why should codeine be avoided in breast feeding mothers?
Mothers vary in their capacity to metabolise codeine to morphine, risk of morphine overdose in the infant.
This does not apply to dihydrocodeine
Why aren’t fentanyl transdermal patches suitable for patients requiring rapid titration of dose/ changing doses all the time?
Due to the long time to steady state
What may increase absorption of fentanyl patches?
Fever (hot skin)
Exposure to external heat
Sevredol
MST continus
Oramorph
Are all brands of what?
Morphine
What legal category is Morphine sulphate solution 2mg/ml?
CD Schedule 5 Inv POM
It is only when the level of morphine exceeds 13mg/ 5ml (2.6mg/ml) that the solution becomes CD Schedule 2!!
The above solution would be 10mg/5ml
What can accumulation of pethidine metabolites (norpethidine) result in?
neurotoxicity
can lead to convulsions in overdose
Tramadol and alcohol?
Alcohol can increase the nervous system side effects of tramadol such as dizziness, drowsiness, and difficulty concentrating.
What migraine medication is not licensed for use in the elderly??
The triptans!
Remember Sumitriptan only licensed for 18y-65y OTC.
What are the triptans (used for migraines) contraindicated in?
Heart problems, previous MI or TIA, moderate severe Hypertension or mild uncontrolled Hypertension.
This is because one of the side effects is an increase in blood pressure
What can cause sensations of tingling, heat, pressure, tightness in the body?
Triptans!
Discontinue if intense
What is the max daily dose of sumitriptan bought OTC doe previously diagnosed migraine?
comes as 50mg tabs OTC: Max 2 daily (100mg)
What can we use to treat cluster headache?
Sumitriptan (given by SC injection!) or Zolmitriptan
How many migraines must someone be having per month to qualify for prophylactic migraine treatment?
2
Prophylaxis of migraines consists of beta blockers- usually Propranolol
Can patients with epilepsy drive a large goods or passenger carrying vehicle?
No
Only motor vehicles
However they can if they haven’t had a seizure for 5 years
What criteria must an epileptic meet if they want to drive their car?
-Seizure free for 1 year (those that have had their first seizure must not drive for 6 months after the event)
-If they only have seizures in their sleep:
3 year past of sleep attacks with no awake attacks
-No recent medication changes or withdrawal: if so 6 months must have elapsed
What risk does Topiramate carry in terms of harm to foetus?
Risk of Cleft palate (cleft lip)
Mrs M has epilepsy but she is not any medication for it at the moment as she hasn’t had a seizure for two years and is now pregnant. Does she need to sign up to the Epilepsy Register?
Yes, whether on medication or not, she still needs to
What drug should be used to manage febrile convulsions?
Brief febrile convulsions (resulting from high temp/ fever) require no specific treatment, just anti-pyretic medication- paracetamol!!
What do patients and carers need to look out for in those taking carbamazepine and phenytoin?
Signs of blood, hepatic or skin disorders: Fever Rash Ulcers Bruising and bleeding
Known as Leucopenia (low white cell count, but this is NOT the same as agranulocytosis)
Which anti epileptics could cause agranulocytosis?
Ethosuximide
Look out for fever, mouth ulcers, bruising, bleeding
Phenobarbital possibly?
Which antieplieptic has been associated with the serious skin rash, Steven Johnsons syndrome?
Lamotrigine
Usually in first 8 weeks of treatment
Which antieplieptic do you need to look out for symptoms of anaemia, bruising and infection?
Lamotrigine
Suggestive of BONE MARROW failure/ blood disorder
Which anti-epileptic requires monitoring of ECG and BLOOD PRESSURE with intravenous use?
Phenytoin
What is the target plasma concentration of the TDM drug phenytoin?
10-20mg/L
What are the signs of phenytoin toxicity?
Nystagmus (uncontrolled eye movement) Diplopia (double vision) Slurred speech Ataxia (uncontrolled body movement) Confusion HYPERglyceamia
In what 3 circumstances should phenytoin treatment be discontinued?
Signs of toxicity
Rash
Hepatoxicity
Coarsened facial appearance, acne, weight loss, constipation, dizziness, mouth tenderness, headache, nausea
All side effects of?
Phenytoin
What antieplieptic requires opthalmological monitoring/ discolouration of ocular tissue/ blue- grey discolouration of nails lips and skin?
Retigabine
Which anti-epileptic is particularly associated with hepatic dysfunction and what are the symptoms?
Sodium valproate
Persistent vomiting, abdominal pain
Anorexia, jaundice, oedema, malaise
Monitor liver function before therapy and during first 6 months of treatment!
Which antieplieptic has been associated with pancreatitis?
Sodium valproate
Should we routinely monitor plasma valproate levels?
No
Not a useful index of efficacy
Should monitor liver function, before and first 6 months
Also measure FBC as blood disorders noted with valproate
Which anti-epileptics can cause problems with vision??
Vigabatrin
Topiramate
In terms of anxiety, what are benzodiazepines indicated for?
Short term relief of severe anxiety (2-4 weeks)
Not for mild anxiety!
Hypnotics should not be used for more than _____ for short term insomnia?
3 weeks
What hypnotics should be avoided in the elderly?
Benzodiazepines and Z drugs
The elderly are more at risk of becoming confused and falling
Which parkinsons medication may exacerbate oedema and therefore should be avoided in those with HEART FAILURE?
Amantadine
Which parkinsons medication may cause hair loss as a side effect?
Selegiline
What is the deal with migraine medication and hypertension?
Ergotamine and triptans: contraindicated in severe/ uncontrolled hypertension
When should SSRI’s be taken?
What about TCA’s?
What about Mirtazepine?
SSRI’s- take in the morning as they are mildly stimulating
TCA’s- take at night as can cause drowsiness
Mirtazepine (tetracyclic)- take at night as can cause drowsiness
At what strength does Oramorph solution turn from a Schedule 5 CD to a schedule 2?
Strengths exceeding 13mg/ 5ml
Zonisamide is an anti-epileptic drug. What should patients be told to avoid when on this medication?
Avoid OVERHEATING (hyperthermia) and ensure they are adequately hydrated during exercise, especially in children, as fatal cases of HEAT STROKE have been reported in children on this medication.
Which anti-epileptic is cautioned in patients with a LOW BODY WEIGHT?
Zonisamide
Monitor weight throughout treatment as fatal cases of weight loss reported in children.
Which anti-epileptic do we need to monitor plasma bicarbonate levels due to risk of metabolic acidosis?
Zonisamide
Metabolic acidosis is an increase in plasma acidity
What should patients on Bromocriptine for parkinsons be advised with regards to OTC drugs?
Important to warn patients not to take OTC sympathomimetics when taking bromocriptine, such as pseudoephedrine, as this could lead to severe peripheral vasoconstriction, ventricular tachycardia and seizures and therefore may be fatal.
Why do parkinsons drugs come as combination preparations e.g. Co-careldopa, Co-benedlopa
PD= decrease in dopamine in the brain so brain cannot control movements.
Dopamine itself is not lipophillic enough to cross the BBB. So we give a dopamine pre-cursor: Levodopa. This is very lipophillic to crosses BBB. But problem is it also gets everywhere in the periphery and causes EPSE’s. So we give it in combo with a periphery-specific dopamine decarboxylase inhibitor in these combo preps, so that it doesn’t get converted to its active form in the periphery.
What are the common SEs of pregabalin (used for neuropathic pain)?
Appetite changes
Blurred vision
Disturbance in muscle control/ movement
Early treatment with____ can delay the need for levodopa therapy in Parkinsons
Selegiline
Which parkinsons drug is used at a dose of 1mg daily?
Rasagaline
Prochlorperazine belongs to the phenothiazine class of antipsychotic agents that are used for the antiemetic treatment of nausea and vertigo. What is their M of A?
Act centrally by blocking the chemoreceptor trigger zone
phenothiazine are a class of antipsychotic agents that are used for the antiemetic treatment of nausea and vertigo and also migraines. Can you name any drugs in this class?
Piperazines:
Prochlorpromazine
Fluphenazine
Trifluoperazine
Also chlorpromazine, promazine, triflupromazine
Which antidepressant drug is associated with weight gain?!
MIRTAZEPINE
Tetracyclic
Which opioid can cause convulsions in overdose?
Pethidine
due to accumulation of its metabolite norpethidine
What is methylphenidates mechanism of action?
N-Methyl-D-Aspartate (NMDA) antagonist (hence the methyl!) it has a neuro-protective effect
Which Benzo is indicated before dental surgery?
Temazepam
Take 30-60 mins before
Also indicated for insomnia- take 30-60 mins before bed time
Has a medium duration of action so good for these two things
Which antidepressant class do we need to do LFT’s before starting?
TCAs
This is because you need to avoid them in severe liver disease as they can cause increased sedative effects (they cause drowsiness as it is)
Surely CNS stimulants Indicated for ADHD would make it worse?
Stimulants increase dopamine and norepinephrine in the brain, and increase blood flow to the brain. This stimulates the child… A child with ADHD has something called “self-stimulation” where they are constantly stimulated and never switch off. Giving drugs that cause stimulation kind of distracts them from this self-stimulation, so it actually calms them down and they just have a normal level of stimulation, as soon as their mind focuses on something else their self-stimulation goes away
What conditions are stimulants (methylphenidate, lisdexamfetamine, atomoxetine etc) used in ADHD cautioned in?
Heart conditions
This is because they can cause tachycardia (fast heart beat)
Which CNS stimulant is licensed for use in Narcolepsy?
Dexamfetamine
Can also use methylphenidate but this is unlicensed use
When starting carbamazepine, what ethnicity of people require testing for the HLA-B*1502 allele and therefore may be more at risk of Stevens Johnson Syndrome?
Thai
and
Han Chinese
people of chinese ethnicity are most at risk of genetic polymorphisms of the CYP2D6 enzyme
