Psychiatry Flashcards
Mechanism of action: Z drugs e.g. Zopiclone
non-benzodiazepine acting on the α2-subunit of the GABA receptor
different distinct site than benzodiazepines but similar effects (used for insomnia and anxiety)
Why should prolonged use of Zopiclone be avoided?
Addiction and tolerance
Mechanism of action: Benzodiazepines (Diazepam, Clonazepam, Lorazepam)
Direct stimulation of GABA receptors by increasing the frequency of chloride channels
Mechanism of action: Promethazine and Cyclizine
H1 receptor antagonists
Side effect of promethazine (H1 receptor antagonist)
Sedation
Ego defence mechanism: displacement
Redirection of emotion to a neutral person
E.g. a person who is angry at their boss goes home and gets angry at their family instead
Ego defence mechanism: reaction formation
Replacing a warded-off idea or feeling by an unconsciously derived emphasis on its opposite
E.g. a gay person being homophobic
Ego defence mechanism: sublimation
Replacing an unacceptable wish with a course of action that is similar to the wish but does not conflict with one’s value system e.g. teenager’s aggression is redirected to perform well in sports
Example of a psychotic defence mechanism
Denial
Distortion
Splitting
Example of an immature defence mechanism
Projection
Example of a neurotic defence mechanism
Displacement
Reaction formation
Repression
Dissociation
Example of a mature defence mechanism
Sublimation
Altruism
Suppression
Humour
Mechanism of action: alcohol withdrawal
chronic alcohol consumption: GABA mediated inhibition (similar to benzodiazepines) and inhibition of NMDA-type glutamate receptors
alcohol withdrawal: decreased inhibitory GABA and increased NMDA glutamate transmission
Features of alcohol withdrawal
symptoms start at 6-12 hours: tremor, sweating, tachycardia, anxiety
peak incidence of seizures at 36 hours
peak incidence of delirium tremens is at 48-72 hours: coarse tremor, confusion, delusions, auditory and visual hallucinations, fever, tachycardia
Management of alcohol withdrawal
1st line: reduced dose protocol of long acting benzodiazepines e.g. chlordiazepoxide or diazepam
Schneider’s first rank symptoms of Schizophrenia
auditory hallucinations
thought disorders
passivity phenomena
delusional perceptions
Types of thought disorders in schizophrenia
Thought insertion
Thought withdrawal (often accompanies thought blocking)
Thought broadcasting (others can hear your thoughts)
Passivity phenomena in schizophrenia
Bodily sensations being controlled by external influence
Actions/impulses/feelings imposed on the individual or influenced by others
Delusional perceptions in schizophrenia
Two stage process: normal object perceived > sudden intense delusional insight into the objects meaning for the patient
e.g. ‘The traffic light is green therefore I am the King’
Negative symptoms of schizophrenia
decreased speech
incongruity/blunting of affect (inappropriate emotion for circumstances)
anhedonia (inability to derive pleasure)
alogia (poverty of speech)
avolition (poor motivation)
catatonia
Definition of dissociation
temporary, drastic change in personality, memory, consciousness or motor behaviour to avoid emotional stress
Mechanism of action: antipsychotics
Block dopamine receptor pathways
Mechanism of action: typical antipsychotics
Non-selective: block a wide variety of D2 receptors in the brain including the mesolimbic pathways
Mechanism of action: atypical antipsychotics
Act on a variety of receptors (D2, D3, D4, 5-HT)
Adverse effects of typical antipsychotics
Extrapyramidal side-effects
Antimuscarinic
Hyperprolactinaemia
Impaired glucose tolerance
Prolonged QT interval
Adverse effects of atypical antipsychotics
Metabolic e.g. weight gain
Olanzapine has higher risk of dyslipidemia and obesity
Hyperprolactinaemia (resperidone)
[Atypical antipsychotics should be used first line in schizophrenia due to reduction in EPSEs]
Examples of typical antipsychotics
Haloperidol
Chlorpromazine
Examples of atypical antipsychotics
Clozapine (used only for treatment resistance after sequential use of two other antipsychotics)
Risperidone
Olanzapine
Aripiprazole (partial agonist - good side effect profile)
Dangerous side effects of Clozapine that need to be monitored
Agranulocytosis
Constipation
Myocarditis
Reduced seizure threshold
Features of EPSEs
Parkinsonism
acute dystonia: sustained muscle contraction - managed with procyclidine
akathisia (severe restlessness)
tardive dyskinesia (most common is chewing and pouting of jaw)
Features of psychosis
hallucinations (e.g. auditory)
delusions
thought disorganisation
- alogia: little information conveyed by speech
- tangentiality: answers diverge from topic
- clanging
- word salad: linking real words incoherently → nonsensical content
Conditions which can include symptoms of psychosis
Schizophrenia (most common psychotic disorder)
Depression (psychotic depression commonly seen in elderly patients)
Bipolar disorder
Brief psychotic disorder (less than one month)
Neurological conditions e.g. PD, HT
Two most likely antipsychotics causing hyperprolactinaemia
Haloperidol (typical)
Resperidone (atypical)
First line pharmacological treatment for children with ADHD
Methylphenidate (ritalin)
Methylphenidate mechanism of action
CNS stimulant
- Dopamine/norepinephrine reuptake inhibitor
Side effects of methylphenidate
Abdominal pain
Nausea
Dyspepsia
Cardio toxicity - baseline ECG needed
Difference between mania (type 1) and hypomania (type 2)
Mania: severe functional impairment or psychotic symptoms for 7 days or more
Hypomania: decreased or increased function for 4 days or more
What medication should be considered stopping in the management of mania?
Antidepressants - increase mania
Management of less severe depression NICE guidelines in order of preference
guided self-help
cognitive behavioural therapy (CBT) (group then individual)
group exercise/mindfulness/ meditation
interpersonal psychotherapy (IPT)
selective serotonin reuptake inhibitors (SSRIs)
Management of more severe depression NICE guidelines order of preference
CBT + antidepressant
Individual CBT
SSRI
SNRI
Psychotherapy
Guided self help
Group exercise
Two screening questions for depression
‘During the last month, have you often been bothered by feeling down, depressed or hopeless?’
‘During the last month, have you often been bothered by having little interest or pleasure in doing things?’
Two questionnaires used to screen for depression
Hospital Anxiety and Depression scale
X
Patient Health Questionnaire
Grading of depression
Alternative physical causes of anxiety
Hyperthyroidism
Cardiac disease
Medication-induced anxiety
Medications that can trigger anxiety symptoms
salbutamol
corticosteroids
antidepressants
caffeine
First line SSRI for generalised anxiety disorder
Sertraline
2nd line: alternative SSRI or SNRI (eg venlafaxine)
3rd line: pregabalin
Management of GAD NICE guidelines stepwise approach
- Education + active monitoring
- Low intensity psychological interventions (guided self help)
- High intensity psychological interventions (CBT or drug treatment)
Features of Korsakoff’s syndrome
Marked memory disorder seen in alcoholics
- anterograde amnesia: inability to acquire new memories
- retrograde amnesia
- confabulation
Underlying cause of Korsakoff’s syndrome
Often follows on from untreated Wernicke’s encephalopathy
Thiamine deficiency
- damage and haemorrhage to the mammillary bodies of the hypothalamus and the medial thalamus
Features of Wernicke’s encephalopathy
Nystagmus
Opthalmoplegia
Ataxia
Risk factors for OCD
family history
age: peak onset is between 10-20 years
pregnancy/postnatal period
history of abuse, bullying, neglect
Personality disorders: cluster A
‘Odd or Eccentric’
Paranoid e.g. perceive attacks on their character
Schizoid e.g. lack of desire
Schizotypal e.g. unusual perceptual disturbances
Personality disorders: cluster B
‘Dramatic, Emotional, or Erratic’
Antisocial e.g. consistent irresponsibility, aggressiveness
Borderline (EU) e.g. unstable interpersonal relationships which alternate between idealisation and devaluation, recurrent suicidal behaviour
Histrionic e.g. inappropriate sexual seductiveness
Narcissistic e.g. grandiose sense of self importance
Personality disorders: cluster C
‘Anxious and Fearful’
Obsessive-compulsive e.g. perfectionism
Avoidant e.g. avoid significant interpersonal contact due to fear of rejection
Dependent e.g. need for excessive reassurance from others
Features of PTSD
re-experiencing
avoidance
hyperarousal
emotional numbing
depression
drug or alcohol misuse
anger
unexplained physical symptoms
Definition of psychosis
a person experiencing things differently from those around them
Factors associated with poor prognosis in schizophrenia
strong family history
gradual onset
low IQ
prodromal phase of social withdrawal
lack of obvious precipitant
Factors associated with an increased risk of suicide
Male sex (although women more commonly attempt suicide, men are more likely to use lethal methods)
History of deliberate self harm
Alcohol or drug misuse
History of mental illness
History of chronic disease
Advancing age
Unemployment or living alone
Being unmarried
Somatostatin disorder definition
Multiple physical symptoms present for at least 2 years with no organic cause
Patient refuses to accept reassurance or negative test results
Conversion disorder definition
Typically involves loss of motor or sensory function
The patient doesn’t consciously feign the symptoms (factitious disorder/Munchausen’s) or seek material gain (malingering)
Uses of benzodiazepines
sedation
hypnotic
anxiolytic
anticonvulsant
muscle relaxant
[should only be prescribed for a short period of time due to tolerance and dependence]
Mechanism of action: barbiturates
Enhance GABA by increasing the DURATION of chloride channel opening
- been replaced by benzodiazepines
Adverse effects of lithium
nausea/vomiting, diarrhoea
fine tremor
nephrotoxicity: polyuria, secondary to nephrogenic diabetes insipidus
thyroid enlargement, may lead to hypothyroidism
ECG: T wave flattening/inversion
weight gain
idiopathic intracranial hypertension
leucocytosis
hyperparathyroidism and resultant hypercalcaemia
Monitoring of patients on lithium therapy
~ Hot topic on exams ~
Sample should be taken 12 hours post-dose
After starting, lithium levels should be performed weekly and after each dose change until concentrations are stable
Once established, lithium blood level should be checked every 3 months
Thyroid and renal function should be checked every 6 months
First line SSRIs in the treatment of depression
Currently preferred:
Citalopram
Fluoxetine
Sertraline post MI
Adverse effects of SSRIs
gastrointestinal symptoms are the most common side-effect
- increased risk of gastrointestinal bleeding
patients should be counselled to be vigilant for increased anxiety and agitation after starting a SSRI
fluoxetine and paroxetine have a higher propensity for drug interactions
SSRI associated with dose-dependent QT interval prolongation
Citalopram and escitalopram
SSRI drug interactions
NSAIDs: NICE guidelines advise ‘do not normally offer SSRIs’, but if given co-prescribe a proton pump inhibitor
warfarin / heparin: NICE guidelines recommend avoiding SSRIs and considering mirtazapine
triptans - increased risk of serotonin syndrome
monoamine oxidase inhibitors (MAOIs) - increased risk of serotonin syndrome
Method of stopping an SSRI
Dose should be gradually reduced over a 4 week period after review by a doctor
Discontinuation symptoms after stopping an SSRI
increased mood change
restlessness
difficulty sleeping
unsteadiness
sweating
gastrointestinal symptoms: pain, cramping, diarrhoea, vomiting
paraesthesia
Use of SSRIs during pregnancy
- Use during the first trimester gives a small increased risk of congenital heart defects
- Use during the third trimester can result in persistent pulmonary hypertension of the newborn
- Paroxetine has an increased risk of congenital malformations, particularly in the first trimester
Use of tricyclic antidepressants
low-dose amitriptyline is commonly used in the management of neuropathic pain and the prophylaxis of headache (both tension and migraine)
lofepramine has a lower incidence of toxicity in overdose
amitriptyline and dosulepin (dothiepin) are considered the most dangerous in overdose
