Chapter 4- Nervous System Flashcards
Name three anticholinesterase inhibitors used in dementia
Donepezil
Rivastigmine
Galantamine
Name the Glutamate receptor antagonist used in more severe dementia
Memantine
Name 4 antiepileptics that have long half lives and can be given once daily at bedtime
Lamotrigine
Perampanel
Phenobarbital
Phenytoin
Name 4 antiepileptics in category 1 that are prescribed by brand
Phenytoin
Carbamazepine
Phenobarbital
Primidone
When can antiepileptic hypersensitivity syndrome start showing symptoms
Between 1 and 8 weeks of exposure
Symptoms of antiepileptic hypersensitivity syndrome
Fever Rash Lymphadenopathy Liver dysfunction Haematological Renal Pulmonary abnormalities Vasculitis Multi-organ failure
Is there a risk of suicidal thoughts and behaviours with all antiepileptic drugs
Yes
What interactions occur with antiepileptics
Usually as a result of enzyme induction or inhibition
Which antiepileptic has the highest teratigenicity risk
Valproate
Topiramate carries with it an increase risk of what if used in the first trimester of pregnancy?
Cleft palate
Women taking antiepileptics meds are advised to take what before conception and during first trimester?
Folate supplementation
The concentration of antiepileptic drugs in the plasma can change during preganancy - doses of which 3 antiepileptics should be adjusted on the basis of plasma drug conc
Phenytoin
Carbamazepine
Lamotrigine
What should be monitored for pregnant women taking topiramate or levetiracetam
Fetal growth
What injection at birth minimises the risk of neonatal haemorrhage associated with antiepileptics
Injection of vitamin K
Name three antiepileptics with an established risk of drowsiness in breast fed babies and that should be used with caution as a result
Primidone
Phenobarbital
Benzodiazepines
Carbamazepine may exacerbate what types of seizures and therefore should not be used?
Tonic
Atonic
Myoclonic
Absence
First line treatment option for absence seizures?
Ethosuximide
True or false: lamotrigine can exacerbate myoclonic seizures
True
True or false: valproate decreases the plasma concentration of lamotrigine
False - it increases it!
What’s responsible for the antiepileptic effects of primidone
It’s converted to phenobarbital
Antiepileptic licensed for adjunctive treatment of seizures in Lennox-gastaut syndrome
Rufinamide
Sodium valproate has widespread metabolic effects and monitoring of what is therefore essential
LFT
FBC
Treatment options for seizures lasting longer than 5 minutes
IV lorazepam
IV diazepam
There is a risk of what syndrome in patients with HLA-B*1502 allele for carbamazepine
Stevens-Johnson syndrome
For carbamazepine what’s the plasma concentration for optimum response
4-12mg/litre (20-50micromol/litre)
Name three things in the rosemont brand of gabapentin oral solution that exceed the WHO recommended limits if high doses are required
Propylene glycol
Acesulfame K
Saccharin sodium
Symptoms of phenytoin toxicity
Nystagmus Diplopia Slurred speech Ataxia Confusion Hyperglycaemia
The usual total plasma phenytoin concentration for optimum response is what?
10-20 mg/litre (or 40-80micromol/litre)
If you take topiramate in the first trimester of pregnancy what is there an increased risk of?
Cleft palate
Topiramate has been associated with what?
Associated with acute myopia with secondary angle-closure glaucoma
Plasma phenobarbital concentration for optimum response is what?
15-40 mg/litre (60-180 micromol/litre)
What can be used in palliative care to reverse the effects of midazolam
Flumazenil
Should modified release preparations of methylphenidate be prescribed by brand?
Yes
Symptoms of overdose of afetamines
Wakefulness Excessive activity Paranoia Hallucinations Hypertension Followed by exhaustion Convulsions Hyperthermia Coma
Name a prodrug of dexamfetamine
Lisdexamfetamine
Long term use of lithium has been associated with what and requires what as a result
Thyroid disorders and mild cognitive and memory impairment - monitor thyroid function every 6 months
When should levels be taken for lithium and what’s the targets?
12 hours after dose
Target: 0.4-1mmol/litre
For acute episodes of mania the target is: 0.8-1mmol/litre
Drug interaction if introducing ACEI, NSAID or diuretic with lithium?
Renal impairment
Symptoms of lithium toxicity
Hypothyroidism Renal dysfunction Intracranial hypertension (headache + visual disturbances)
During the first few weeks of antidepressant treatment there is an increased risk of what?
Agitation
Anxiety
Suicidal ideation
What class of antidepressant is first line and why?
SSRIs - better tolerated and safer in overdose
What does St. John’s wort do to metabolising enzymes?
Induces drug metabolising enzymes
What’s the active ingredient in St. John’s wort
Hypericum perforatum
True or false: elderly patients may take longer to respond to antidepressants
True
Antidepressant therapy (particularly SSRIs) have been associated with hyponatraemia and can make what symptoms develop?
Drowsiness
Confusion
Convulsions
Characteristics of serotonin syndrome fall into what three categories
Neuromuscular hyperactivity
Autonomic dysfunction
Altered mental state
Symptoms associated with neuromuscular hyperactivity in serotonin syndrome
Tremor Hyperreflexia Clonus Myoclonus Rigidity
Symptoms associated with autonomic dysfunction in serotonin syndrome
Tachycardia BP changes Hyperthermia Diaphoresis Shivering Diarrhoea
Symptoms associated with altered mental state in serotonin syndrome
Agitation
Confusion
Mania
Name the three less sedating TCAs & related antidepressants
Imipramine
Lofepramine
Nortriptyline
True or false: escitalopram is the prodrug of citalopram
False! It’s actually the active enantiomer of citalopram
True or false: low gastric pH causes reduced absorption of the paroxetine oral suspension
False - a high gastric pH does
First generation antipsychotic act predominantly by blocking what?
Dopamine D2 receptors in the rain (not not selective) therefore side effects
First generation phenothiazine antipsychotic derivatives can be split into how many groups
THREE
Name the group 1 phenothiazine derivative antipsychotics and what are their side effects
Chlorpromazine
Levomepromazine
Promazine
Pronounced sedative
Moderate antimuscarinic
Moderate extrapyramidal
Name the group 2 phenothiazine antipsychotic derivatives and what are the side effects
Pericyazine
Moderate sedative
Fewer extrapyramidal than group 1 & 3
Drugs in group 3 phenothiazine antipsychotic derivatives and side effects
Fluphenazine
Perphenazine
Prochlorperazine
Trifluoperazine
Fewer sedative and antimuscarinic effects but more pronounced extrapyramidal effects than group 1&2
Name two butyrophenones and which class of the phenothiazine derivatives do they resemble?
Benperidol
Haloperidol
Group 3!
Name a diphenylbutylpiperidine
Pimozide
Name a substituted benzamide
Sulpiride
Extrapyramidal symptoms of antipsychotics include what
Parkinsonism
Dystonia + dyskinesia
Akathisia
Tardive dyskinesia
If dopamine inhibits prolactin release - what do first and second generation antipsychotics cause?
Hyperprolactinaemia because they block dopamine therefore no inhibition of the prolactin
Aripiprazole reduces prolactin - why?
It’s only a dopamine receptor partial agonist
Which antipsychotics are most likely to cause symptomatic hyperprolactinaemia
Risperidone
Amisulpride
First generations
Symptoms of hyperprolactinaemia
Sexual dysfunction
Reduced bone mineral density
Breast enlargement
Galactorrhoea
Antipsychotics have been associated with what cardiovascular side effects
Tachycardia
Arrhythmias
Hypotension
Prolong QT
All antipsychotics can cause weight gain and hyperglycaemia- which ones are of particular concern with causing diabetes?
Clozapine
Olanzapine
Quetiapine
Risperidone
Name a rare but potentially fatal side effect of all antipsychotic drugs and how long can it last for after discontinuation of the drug
Neuroleptic malignant syndrome
5-7 days
True or false: first generation antipsychotics are better at treating the negative symptoms of schizophrenia
False! Second generation are better
True or false: first generation antipsychotics are less likely to cause diabetes than the second generation
TRUE DAT
Haloperidol dose adjustments when?
If smoking started or stopped during treatment
Monitoring requirements for pimozide (1st generation antipsychotic)
ECG- there’s been reports of unexplained sudden death - caution QT prolongation
What’s the name given to the phenothiazines that explains the facial and skeletal muscle spasms and ocugyric crises
Acute dystonic reactions
True or false: phenothiazines are hepatotoxic
True dat
Is BP monitoring mandatory for sulpiride?
No- does not affect blood pressure as much as other antipsychotics
Name four first generation antipsychotic depot injections
Flupentixol decanoate
Fluphenazine decanoate
Haloperidol decanoate
Zuclopenthixol decanoate
How can you treat hypersalivation side effect of clozapine
Hyoscine hydrobromide- aslong as patient not at risk of addictive antimuscarinic side effects of hyoscine and clozapine combined
Treatment options for muscle cramps in motor neurone diseases
Quinine Baclofen Tizanidine Dantrolene Gabapentin
Name three non ergot derived dopamine agonists used in Parkinson’s disease
Pramipexole
Ropinirole
Rotigotine
Name three ergot derived dopamine agonists used in Parkinson’s
Bromocriptine
Cabergoline
Pergolide
Why are ergot derived dopamine agonists used to a less extent than non ergot derived DA in Parkinson’s
Risk of fibrotic reactions
What is apomorphine
Potent dopamine receptor agonist used in advanced Parkinson’s disease to help with off periods
Name two dopa decarboxylase inhibitors
Benserazide
Carbidopa
Name two MAO type B inhibitors used in Parkinson’s
Rasagiline
Selegiline
Safinamide
Name three antimuscarinic drugs used in Parkinson’s
Orphenadrine
Procyclidine
Trihexyphenidyl
When would you introduce COMPT inhibitors in Parkinson’s disease
In patients on levodopa + dopa decarboxylase experiencing end of dose motor fluctuations
When adding COMPT inhibitors to Parkinson’s meds regimen what may need to be reduced
Levodopa dose by around 10-30%
Name three COMT inhibitors
Entacapone
Opicapone
Tolcapone
Why is there restrictions from the MHRA on the use of domperidone
It’s associated with a small increased risk of serious cardiac side effects
What are the MHRA restrictions on domperidone
Only indicated for N&V
lowest effective dose for max one week
Contraindicated in cardiac conditions or at risk of QT prolong and in combo with CYP3A4 inhibitors
Not in severe hepatic impairment
Recommended dose in over 12 and over 35kg is 10mg up to TDS
Recommended dose in children under 35kg is 250mcg/kg up to TDS
MHRA recommendations on metoclopramide
Particular indications
Max 5 days treatment
10mg up to TDS - max daily dose 500mcg/kg
IV slow plus over 3 mins
What’s aprepitant and fosaprepitant
Neurokinin receptor antagonists used for nausea and vomiting - fosaprepitant is the prodrug of aprepitant
MHRA warning about promethazine
Children under 6 years should not be given OTC cough and cold meds containing promethazine
Pain in sickle cell disease
Paracetamol
Ibuprofen
Codeine/dihydrocodeine
Morphine/diamorphine
What painkiller should be avoided in sickle cell disease and why?
Pethidine - accumulation of a neurotoxic metabolite which can precipitate seizures
Three drugs often adequate in dental pain
Paracetamol
Ibuprofen
Aspirin
Side effects of Opioids
Nausea & vom Severe constipation Drowsiness Resp depression Dependence
Which has longer duration of action: buprenorphine or morphine?
Buprenorphine
Sublingual buprenorphine lasts how long
6-8hrs
Benefit of diamorphine in palliative care
Greater solubility means smaller injection volume, less nausea and less hypotension
Fever/increased heat to buprenorphine patch can cause what
Increased absorption
Methadone/buprenorphine for opioid dependence - supervised consumption should be for how long
3 months
Max dose of codeine in adults
240mg (60mg QDS)
Codeine is contraindicated in patients who are what metabolisers
Ultra rapid metabolisers (CYP2D6 ultra rapid metabolisers)
Why are dispersive or effervescent analgesic preferred in migraine?
Peristalsis is reduced therefore reducing absorption
Name the short acting Z drugs used for insomnia
Zaleplon
Zolpidem
Zopiclone
Name three shorter acting benzodiazepines with little or no hangover effect
Loprazolam
Lormetazepam
Temazepam
Caution/further information for benzodiazepines
Paradoxical effects - increase in hostility and aggression
Three drugs used in narcolepsy
Sodium oxybate
Pitolisant
Modafinil
Drug used in alcohol withdrawal
Chloridazepoxide
Three drugs used in alcohol relapse prevention
Acomprosate
Naltrexone
Disulfiram (2nd line)
Drug used to reduce alcohol intake
Nalmefene
Two drugs used to treat nicotine dependence
Bupropion
Varenicline
Can you use nicotine replacement therapy and bupropion or varenicline together?
It’s not recommended
Smoking induces what enzyme and which drugs should therefore be monitored
CYP1A2 Theophylline Cinacalcet Ropinirole Antipsychotics (cloz, olanz, chlorpromazine, haloperidol)
Which is more sedating- methadone or buprenorphine?
Methadone
How long does it take methadone to reach steady state for patients on a stable dose and why?
3-10 days due to long half life
Signs of neonatal withdrawal from opioids
High pitched cry Rapid breathing Hungry but ineffective suckling Excessive wakefulness Hypertonicity Convulsions
MHRA/CHM advice with varenicline for nicotine dependence
Suicidal behaviour - discontinue if they develop agitation, depressed mood, suicidal thoughts
Hypnotics in elderly can cause what
Ataxia
Confusion
Falls
Long term treatment of bipolar disorder should continue for how long after the last manic episode
At least 2 yrs (5 yrs in those at risk of relapse)
Name the MAOI that has the greatest stimulant action and therefore causes increased risk of hypertensive crisis
Tranylcypromine
Which two MAOIs are more likely to cause hepatotoxicity than tranylcypromine
Phenelzine
Isocarboxazid
CI to SSRIs
Poorly controlled epilepsy and manic phase
4 antipsychotics with increased risk of hyperglycaemia and weight gain
Clozapine
Olanzapine
Quetiapine
Risperidone
Two first generations that have less risk of causing diabetes
Fluphenazine
Haloperidol
Of the second generations which are less likely to cause diabetes &a weight gain
Amisulpride
Aripiprazole
