Psychiatric Pharmacology Flashcards
What are the mechanism of action of typical antipsychotics?
Dopamine D2 receptor antagonists, blocking dopaminergic transmission in the mesolimbic pathways.
What is the mechanism of action of atypical antipsychotics?
Act on a variety of receptors (D2, D3, D4, 5-HT).
What are the adverse effects of typical antipsychotics?
Extrapyramidal side effects
Hyperprolactinaemia (amenorrhoea)/galactorrhea),:
Impotence, galactorrhoea, headaches, hypopituitarism, visual field defects)
What are the examples of typical (first generation) anti psychotics?
Haloperidol
Chlopromazine
What are the side effects of atypical antipsychotics?
Metabolic
Extra pyramidal and hyperprolactinaemia side effects are less common.
What are the extrapyramidal side effects?
Parkinsonism
Acute dystocia
Akathisia
Tardive dyskinesia
What are the other side effects of antipsychotics?
C- dry mouth, blurred vision, urinary retention, constipation
Sedation, weight gain. Raised prolactin Impaired glucose tolerance Neurlopectic malignant syndrome Reduced seizure threshold (greater with atypical) Prolonged QT interval (haloperidol)
What are the specific warnings when antipsychotics are used in elderly patients?
Increased risk of stroke
Increased risk of VTE.
What is meant by Parkinsonism?
Any condition which causes a combination of the movement abnormalities seen in Parkinson’s disease- tremor, slow movement, impaired speech or muscle stiffness.
What is meant by acute dystocia?
Sustained muscle contraction
Can be managed with procyclidine
What is akathisia?
Severe restlessness
What is tardive dysknesia?
Face and/or body make sudden, jerky or slow wasting movements which a person cannot control.
What drug is particularly associated with prolonged QT interval?
Haloperidol
What is neuroleptic malignant syndrome?
Rare but potentially life threatening reaction to the use of almost any of a group of anti psychotic drugs or major tranquillisers (neuroleptic). It affects the nervous system and causes symptoms like a high fever and muscle stiffness.
Why is it anti psychotics cause hyperprolactinaemia?
Anti psychotics are dopamine antagonists
Dopamine is a prolactin antagonist
What are the metabolic side effects of antipsychotics?
Dysgylcaemia
Dyslipidaemia
Diabetes mellitus
What is the timeline like for alcohol withdrawal?
Symptoms start at 6-12 hours: tremor, sweating, tachycardia, anxiety
Peak incidence of seizure is at 36 hours
Peak incidence of delirium tremens is at 48-72 hours
What are the signs someone is in delirium tremens?
Coarse tremor Confusion Delusions Auditory and visual hallucinations Fever Tachycardia
What is the management of alcohol withdrawal?
Benzodiazepines- chlordiazepoxide
(Lorazepam maybe favoured in patients with hepatic failure)
Carbamazepine also effective in treatment of alcohol withdrawal
What are the 5 stages of grief?
Denial Anger Bargaining Depression Acceptance
What investigations are needed before starting antipsychotics?
FBC (also clozapine requires this weekly) U &E LFTS Lipids Weight Fasting blood glucose Prolactin ECG Blood pressure (both at baseline and frequently during dose titration)
(Also should do a CV risk assesment annually)
What should you do if someone has missed their clozapine?
If doses are missed for more than 48 hours they need to be tapered, this is because when you start it after a break it can actually make the side effects much worse ie: blood pressure changes, drowsiness and dizziness. If there is a gap in treatment of 3 days (72 hours) then you may also require more frequent blood tests for a short period.
What are the features of anorexia nervosa?
Reduced body mass index Bradycardia hypotension Enlarged salivary glands Cold intolerance Hypercarotenaemia
What is physiological abnormalities?
Hypokalaemia Low FSH, LH, oestrogen and testosterone Raised cortisol and growth hormone Impaired glucose tolerance Hypercholesterolaemia Hypercarotinaemia Low T3
What is the difference between somatisation and illness anxiety disorder (hypochondriasis)?
S= stands for symptoms
Multiple physical symptoms present for at least 2 years
Patient refuses to accept reassurance or negative test results
Illness anxiety disorder (hypochondriasis)
Persistent belief in the presence of an underlying SERIOUS DISEASE- cancer
Patient again refuses to accept reassurance or negative test results
What is conversion disorder?
Typically involves loss of motor or sensory function that cannot be explained medically and may be caused by stress.
What is dissociative disorder?
Process of separating off certain memories from normal consciousness
In contrast to conversion disorder involves psychiatric symptoms eg: amnesia, fugue, stupor
Dissociative identity disorder is the new term for multiple personality disorder as it is the most severe form of dissociative disorder.
What is factitious disorder?
The intentional production of physical or psychological symptoms- purposefully causing symptoms for example; a diabetic taking too much insulin to cause hypos
Also called Munchausens syndrome
What is malingering?
Lying or exaggerating for financial gain
What is raised in anorexia?
Growth hormone Glucose Salivary glands Cortisol Cholesterol Carotinaemia
What is the SSRI of choice in children and adolescents?
Fluoxetine
If someone is on an antipsychotic (clozapine) and they develop an infection, what should you do?
You need to do a
FBCto exclude life threatening side effects of clozapine (neutropaenia)/agranulocytosis
What is clozapine?
One of the first atypical agents to be developed
For this reason clozapine should only be used in patients resistant to other anti psychotic medication.
What are the adverse effects of clozapine?
Agranulocytosis neutropenia Reduced seizure threshold Constipation Myocarditis Hyper-salivation
When might dose adjustment of clozapine be necessary?
If smoking is started or stopped during treatment
What is used antidepressant wise as a second line for depression?
Mirtazapine
What is a benefit of mirtazapine despite its side effects?
Large increase in appetite and subsequent weight gain and drowsiness
These side effects are so pronounced that mirtazapine has been known to be used as an appetite stimulant and sleep aid off formulary.
What class is mirtazapine?
NASSAs
Noradrenaline serotonin specific antidepressants
What class is venlafaxine?
Serotonin and noradrenaline reuptake inhibitor
What are the side effects of serotonin antagonist and reuptake inhibitors (like venlafaxine)?
Minimal anticholinergic side effects and relatively low cardio toxicity compared with TCAs
May cause dry mouth, blurry vision, constipation, drowsiness, sedation, hallucinations, memory problems, urinary retention.
What are the poor prognostic indicators of schizophrenia
Strong family history Gradual onset Low IQ Prodromal phase of social withdrawal Lack of an obvious precipitant
How does zopiclone work?
Binds to GABAA containing receptors, causing an enhancement of the actions of GABA to produce the therapeutic and adverse effects of zopiclone.
What are the side effects of zopiclone?
Agitation, bitter taste in mouth, constipation, decreased muscle tone, dizziness, dry mouth and increased risk of falls (especially in elderly)
Convulsions, tremor, hyperventilation May be seen in zopiclone withdrawal
When should you. Take mirtazapine?
In the evening as it can be sedative
How do monoamine oxidase inhibitors normally work?
Serotonin and noradrenaline are normally metabolised by monoamine oxidase in the presynaptic cell
Give examples of monoamine oxidase inhibitors…
, phenelzine
Tranylcypromine
Non selective monoamine oxidase inhibitors are not used frequently due to side effects, when might you use them?
Used in the treatment of atypical depression (hyperphagia) and other psychiatric disorders.
What food should people avoid when taking non selective monoamine oxidase inhibitors?
Tyramine containing foods- cheese, pickled herring, bovril, oxo, marmite and broad beans.
As this increases the risk of hypertensive crisis.
