Psychiatry Flashcards
acetylcholinesterase inhbiitors are indicated for which conditions?
Alzheimers disease
Dementia in Parkinsons disease
what is the MoA of acetylcholinesterase inhibors (donepezil, rivastigmine) in alzhemiers and parkinsons dementia?
increases availabilty of acetylcholine for neurotransmission improving cognitive function and reducing rate of decline
what are some side effects of acetylcholinesterase inhibotors?
N&V, diarrhoea
bradycardia and heart block
acetylcholinesterase inhibitors should be used in caution in which pt groups?
asthma
COPD
risk of peptic ulcers
heart block
examples of acetylcholinesterase inhibitors?
donepezil
rivastigmine
what drug interactions are important to consider when prescribing acetylcholinesterase inhibitors?
B blockers- bradycardia/ heart block
NSAIDs- peptic ulcers
how can explain acetylcholinesterase inhibitord to teh patient?
treatment improves memory and brain function and may slow rate of decline
should acetylcholinesterase inhibotrs be monitored?
review at 2-4 weeks for adverse effects
repeat cognitive assessment at 3 months to assess efficacy
why are some patients advised to take donepezil in the mornign rather than the usual bed time dose?
can cause vivid dreams which could be problematic for pts
when are SSRIs indicated for use?
depression
panic disorder
OCD
name some SSRIs?
citalopram
fluoextine
sertraline
escitalopram
what is the MoA of SSRIs?
inhibit neuronal reuptake of 5-HT from synaptic cleft
which SSRI can prolong the QT interval?
citalopram
what is the triad in serotonin syndrome?
autonomic hyperactivity, altered mental state, neuromuscular excitation
how are SSRIs metabolised?
metabolised by liver
SSRIs should not be given alongside which other drugs?
monoamine oxidase inhibitors as may precipitate serotonin syndrome
drugs that prolong the QT interval i.e. antipsychotics
how long should patients carry on with SSRI treatment?
at least 6 months even after feeling better from depression
SSRIs should be stopped over how long?
4 weeks
when are tricyclics indicated?
second line in dperession (SSRIs ineffective)
neuropathic pain
what is the MoA of tricyclic antdepressants?
inhibit neuronal reuptake of 5-HT and noradrenaline from synaptic cleft
side effects of tricyclic antodepressants?
blockade of antimuscarins receptors cause dry mouth, constipation, retention and blurred vision
tricyclic antidepressants should not be given alongside which other drugs?
monoamine oxidase inhibitors as both inc 5-HT and noradrenaline
examples of tricyclic antidepressants?
amitriptyline
lofepramine
what is the MoA of antidepressants venlafaxine and mirtazapine?
venlafaxine is an SNRI
mirtazapine is an antagonist of inhibitory pre-synaptic a2-receptors
both inc availability of monoamines for transmission
indications for venlafaxine?
depression (SSRIs inneffective)
generalised anxiety disorder
when during the day should mirtazapine be taken?
at night to beneift from sedative effects
how are the sedative effects of mirtazapine affected by the dose?
sedative effects less severe at higher doses
are first or second generation antipsychotics typical?
first generation = typical
second generation = atypical
name some first gen (typical) antipsychotics?
haloperidol, chlorpromazine, prochlorperazine
indications for first gen (typical) antipsychotics?
psychomotor agitation causing dangerous/ violent behaviour
schizophrenia
bipolar disorder
MoA of antipsychotics?
block post-synpatic dopamine D2 receptors
all have some sedative effect
important adverse effects of first gen (typical) antipsychotics?
extrapyramidal effects: acute dystonia, akathisia, tardive dyskinesia
drowsiness
hypotension
prolonged QT interval
erectile dysfunction
important adverse effects of second gen (atypical) antipsychotics?
extrapyradimal effects: more common w first gen
prolonged QT interval
what are extrapyramidal effects?
‘drug induced movement disorders’
acute dystonia, akathasia (restlessness), tardive dyskinesia
what rare but serious side effect can occur with antipsychotic use?
Neuroleptic malignant syndrome
rigidity, confusion, autonomic dysregulation, pyexia
which pt population are particulary sensitive to antipsychotics?
elderly- start with lower dose
who should not take antipsychotics?
dementia- inc risk of stroke and death
parkinsons- extrapyradimal effects
cardiovascular disease- interacts with drugs prolong QT interval
which first gen (typical) antipsychotic is a popular choice for managing acute violent behaviour?
haloperidol
oral antipsychotics are best taken at which time?
bed time
which antipsychotic requires regular blood test monitoring?
Clozapine- risk of agranulocytosis (neutrophil deficiency)
name some second gen (atypical) antipsychotics?
quetiapine, olanzapine, risperidone, clozapine
when are benzodiazepines indicated?
management of alchol withdrawal
sedation
short term treatment of severe, distressing anxiety
list some benzodiazepines?
diazepam, lorazepam, temazepam, chordiazepoxide, midazolam
MoA of benzodiazepines?
facilitate and enhance binding of GABA to the GABAA receptor
opens chloride channel making cell more resistant to depolarisation
why are benzos useful in alcohol withdrawal?
alcohol acts on GABAA receptor so chronic alcohol use causes tolerance- abrupt cessation provokes the excitatiry state of alcohol withdrawal
benzos can be withdrawn in a gradual and controlled way
important adverse effects of benzos?
drowsiness, sedation, dependence can develop
abrupt cessation can cause withdrawal reaction similar to alcohol
benzos should be used with caution in which patient groups?
elderly, repiratory impairment, neuromuscular disease, liver disease
which benzodiazepine is best for sedation in the short term?
midazolam
what psychiatric illness is lamotrogine indicated for?
bipolar depression, not mania or hypomania
lamotrogine binds to which channels?
Na+ channels interfering with Na influx
common adverse effects of lamotrogine?
headache, drowsiness, irritability, blurred vision, GI upset
can develop skin rash which may be sign of severe hypersensitivity reaction
is lamotrogine safe during pregnancy?
yes- no evidence to suggest inc risk of congenital abnormnality but should be discussed with pt
lamotrogine is metabolised by the ?
liver: hepatic glucuronidation
may need to reduce dose in heptic impairment
which drugs interact with lamotrogine by inducing glucuronidation?
carbamazepine, oestrogens, rifampicin, protease inhibitors
all can cause lamotrogine levels to fall
why is lamotrogine unique with its use in bipolar disease?
treats depressive symtpoms without increasinf risk of switch to mania
indications for naloxone?
treatment of opiod toxicity
(respiratory depression)
MoA of Naloxone?
binds to opiod receptors acting as competitive antagonist
if an opiod is present naloxone displaces it from its receptors and reverses its effects
psychiatric indication for sodium valproate?
bipolar disorder- acute manic episodes and prophylaxis of recurrence
which pt population should sodium valproate be avoided in?
women of child bearing age
avoid in hepatic and severe renal impairment
