Psychiatry Flashcards
What is the most common inherited cause of learning disability?
Fragile X syndrome
What is the most common avoidable cause of learning disability?
Foetal alcohol syndrome
What are 4 known, predisposing medical conditions for ASD?
1) Fragile X syndrome
2) Infantile spasms
3) Congenital rubella
4) Tuberous sclerosis
What genetic mutation is seen in Fragile X syndrome?
An expansion of the CGG trinucleotide repeat in the FMR1 gene on the X chromosome.
What gene is implicated in Fragile X syndrome?
FMR1 gene on X chromosome
What trinucleotide is implicated in Fragile X?
CGG
Classic features in Fragile X syndrome?
1) Learning disabily
2) Delayed speech & motor development
3) Large testes
4) Long, narrow face
5) Prominent jaw & forehead
6) Large, protruding ears
What 3 conditions may be associated with Fragile X?
1) Autism
2) ADHD
3) Epilepsy
How is Fragile X diagnosed?
DNA test that counts number of CGG repeats (FMR1 testing)
What condition is ASD most commonly associated with?
ADHD (50%)
What is trisomy 18?
Edward’s syndrome
What is trisomy 13?
Patau syndrome
People with learning disabilities may present differently with depression.
What type of symptoms are often more prominent?
Biological e.g. agitation, appetite, sleep
What valve defect can be seen in Fragile X?
Mitral valve prolapse
What CNS abnormalities can be seen in foetal alcohol syndrome?
1) Decreased cranial size
2) Structural brain abnormalities
3) Problems with attention
4) Cognitive difficulties
Prevalence of ASD in UK?
1 in 100
What may depressive features in people with learning disability also indicate the onset of?
Dementia
What IQ score defines a learning disability?
<70
Stepwise management of PTSD?
1st –> trauma-focused CBT or eye movement desensitisation and reprocessing (EMDR) therapy
2nd –> venlafaxine or SSRI
3rd –> risperidone (severe cases)
What SNRI is indicated in PTSD?
Venlafaxine
What antipsychotic is indicated in severe cases of PTSD?
Risperidone
What is de Fregoli syndrome?
The delusion of identifying a familiar person in various people they encounter.
What is Capgras syndrome?
The delusion that a person closely related to the patient has been replaced by an impostor.
When lithium levels are stable, how often are levels checked?
Every 6 months, 12 hours after last dose
If a first line SSRI such as sertraline is ineffective or not tolerated in GAD, what is next step?
Try another SSRI or SNRI
Diagnostic criteria for mild depression
2 core + 2 other
Diagnostic criteria for major depression
3 core + 4 other
What is the mechanism of action of memantine?
Glutamate antagonist (NMDA receptor antagonist)
When is memantine indicated 1st line over cholinesterase inhibitors (e.g. donepezil)?
1) Bradycardia (<60bpm)
2) Heart block
Which lobes are affected in Alzheimer’s?
Atrophy of medio-temporal lobes
What 2 medications are indicated in OCD?
1) SSRIs
2) Clomipramine
Which Alzheimer’s medication is contraindicated in bradycardia?
Donepezil
Disruption to which pathway produces the positive symptoms of schizophrenia?
Increased dopamine activity in the MESOLIMBIC pathway.
Disruption to which pathway produces the negative symptoms of schizophrenia?
HYPOactivity of dopamine in the MESOCORTICAL pathway causes negative, cognitive & affective symptoms.
What investigations are needed prior to starting lithium?
1) Weight
2) U&Es
3) ECG
4) Pregnancy test
5) TFTs
6) Ca2+
What is the link between sodium and lithium?
The kidneys treat lithium and sodium similarly.
This is the reason why sodium DEPLETION can significantly ELEVATE lithium reabsorption.
Causes of sodium depletion (that can predispose to lithium toxicity):
1) diuretics
2) dehydration
3) febrile illness
4) GI loss
Use of which diuretic is most likely to cause lithium toxicity?
Thiazide diuretics
How does lithium use affect sodium levels?
Lithium can cause sodium depletion.
How can a low sodium diet affect lithium levels?
A low-sodium (salt-restricted) diet can decrease lithium elimination, leading to increased risk of toxicity in lithium users who reduce their salt intake.
What are 3 possible renal effects of lithium use?
1) Decrease in eGFR
2) Nephrogenic diabetes insipidus
3) Increased risk of CKD
Why is lithium contraindicated in Cardiac disease or Addison’s disease?
As it causes salt depletion.
What does a prolonged QT interval represent?
Delayed ventricular depolarisation
How can lithium affect the thyroid?
Can cause hypothyroidism
What is typically the most prevalent adverse effect experienced by patients treated with clozapine?
Clozapine-induced hypersalivation
What cardiac adverse effect can clozapine cause?
Myocarditis
Clozapine and epilepsy?
Clozapine LOWERS the seizure threshold.
Which SSRI is licensed for treatment in bulimia?
Fluoxetine
How can TCAs affect the BP?
Can cause hypotension due to inhibition of a1 receptors (causing smooth muscle relaxation).
Cardiac effect of SSRIs?
Can prolong QT interval
What are 2 major contraindications of clozapine?
1) history of neutropenia
2) severe heart disease
Impact of TCAs on dopamine?
TCAs block D2 receptors –> raised prolactin (e.g. menstrual disturbance, galactorrhoea, sexual dysfunction)
What class of drug is mirtazapine?
NaSSA - noradrenergic and specific serotonergic antidepressants
What is the mechanism of sodium valproate?
Increases activity of GABA (relaxing effect on brain)
What is the effect of a prolonged QT interval?
Long QT syndrome can cause sudden fainting and seizures.
Young people with LQTS syndrome have an increased risk of sudden death.
What are some side effects of sodium valproate?
- enzyme inhibitor
- hair loss
- hepatitis
- weight gain
- GI upset
- ataxia
- tremor
- teratogenic
- thrombocytopenia
Which medication can exacerbate absence seizures?
Carbamazepine
1st line antiepileptic for tonic clonic seizure?
Males: sodium valproate
Females: levetiracetam or lamotrigine
1st line antiepileptic for absence seizures?
Ethosuximide
2nd line antiepileptic for absence seizures?
Male: sodium valproate
Female: lamotrigine or levetiracetam
1st line management of myoclonic seizures?
Male: sodium valproate
Female: levetiracetam
1st line management of tonic or atonic seizures?
Males: sodium valproate
Females: lamotrigine
1st line antiepileptic for focal seizures?
Lamotrigine or levetiracetam
2nd line antiepileptic for focal seizures?
carbamazepine
What is the 1st line management of trigeminal neuralgia?
Carbamazepine
1st line management of neuropathic pain?
Amitriptyline, duloxetine, gabapentin or pregabalin
Impact of antipsychotics & epilepsy?
Antipsychotics lower the seizure threshold
2nd line management of bipolar (i.e. that is resistant to lithium)?
Carbamazepine
What are some side effects of carbamazepine?
1) Aplastic anaemia
2) Agranulocytosis
3) Hyponatraemia
Why should benzos be avoided in liver failure?
Can precipitate hepatic encephalopathy
Benzos & neuromuscular disorders (e.g. mysthenia gravis)?
Benzos are contraindicated in NMD
Interaction between carbamazepine and antipsychotics?
Carbamazepine lowers the efficacy of antipsychotics
If the use of benzos in liver failure (e.g. alcohol withdrawal) is essential, which should be given?
Why?
Lorazepam - depends less on liver for elimination
Impact of AChEIs on Schlemm’s canal?
Opens it
IOP with anticholinergics vs acetylcholinesterase inhibitors (e.g. donepezil)?
Anticholinergics –> closes Schlemm’s canal and increases IOP
Acetylcholinesterase inhibitors –> opens Schlemm’s canal and decreases IOP
Cautions & contraindications of AChEIs?
Caution:
1) Asthma and COPD (due to increased secretions)
2) Those at risk of developing peptic ulcers
Contraindications:
1) Heart block or sick sinus syndrome
2) Bradycardia
What MMSE score indicates severe dementia?
<10
Contraindications of carbamazepine?
1) pregnancy
2) hepatic, renal or cardiac disease – increased risk of toxicity
Contraindictions of z drugs?
1) Obstructive sleep apnoea
2) Respiratory muscle weakness
3) Respiratory depression
How long should z drugs be prescribed for?
Max 4 weeks
Mechanism of naloxone?
Opioid antagonist
Which dopamine agonist is used in the management of NMS?
Bromocriptine
MOA of cocaine?
Monoamine reuptake inhibitor
Why are SSRIs contraindicated in epilepsy?
SSRIs can cause hyponatraemia –> can cause seizures when severe
Symptoms of SSRI discontinuation syndrome?
- increased mood change
- restlessness
- difficulty sleeping
- unsteadiness
- sweating
- GI symptoms: pain, cramping, diarrhoea, vomiting
- paraesthesia (electric shock sensations)
Mx of hypomania in a patient with a known diagnosis of bipolar?
Routine referral to community mental health team
3 key features of PTSD?
1) hyperarousal e.g. hypervigilance
2) avoidance
3) re-experiencing e.g. flashbacks, nightmares
How can lithium affect WBCs?
Lithium can precipitate a BENIGN leucocytosis
ECG features of hypokalaemia?
1) Flattened T waves
2) Tall P waves
3) Can cause heart block
Peak incidence of delirium tremens after stopping alcohol?
48-72 hours
Advance decision/directive vs advance statement?
Advance decision/directive:
- documents REFUSAL of certain treatments in the future
- legally binding
Advance statement:
- documents general preference about care e.g. wishes, values, beliefs
- not legally binding
How are advance decisions and the MHA interlinked?
If person is being detained/treated under the MHA, their advance decisions/directives do NOT apply.
Except ECT (you can make an advance decision to refuse ECT).
Give the top 4 ‘nearest relatives’ in MHA
1) Husband, wife or civil partner
2) Son or daughter
3) Mother or father
4) Brother or sister
How long does a standard DoLS last?
1 year
How long does an emergency DoLS last?
7 days
Can a DoLS be renewed?
No must reapply
What is a likely side effect of memantine?
Constipation
What is the definitive diagnostic test for CJD?
Tissue biopsy
Why are those with Down’s syndrome more likely to get early onset Alzheimer’s?
Due to extra copy of APP –> can lead to early onset beta amyloid plaques.
What is an alternative to AChEIs in patients with dementia with a contraindication e.g. QT prolongation?
Cognitive stimulation therapy
What is alogia?
Paucity of speech (negative symptom of schizophrenia)
What neutrophil count should lead to the discontinuation of clozapine?
<0.5
What can clozapine toxicity be precipitated by? Why?
Acute infection e.g. pneumonia
Clozapine is metabolised by P450 system –> downregulation of these enzymes during infection/inflammation can lead to increased clozapine level
What electrolyte abnormality is most likely to be found in blood tests following a panic attack?
Why?
Hypocalcaemia
Anxiety –> hyperventilation –> respiratory alkalosis –> causes calcium to bind to albumin –> lowers free calcium –> hypocalcaemia –> paraesthesia.
What ECG change may be seen in refeeding syndrome?
Why?
Prominent U waves
Due to hypokalaemia
What murmur can be heard in AN?
Pansystolic murmur (due to mitral valve prolapse)
What cardiac abnormalities can AN cause?
- bradycardia
- mitral valve prolapse
- hypotension
- HF
What test is used to assess muscle wasting in patients with anorexia nervosa?
What is a red flag?
Sit up squat stand (SUSS) test
Red flag = not being able to stand up from chair without using hands
What do prominent U waves on an ECG indicate?
Hypokalaemia
What is semantic dementia a type of ?
FTD
What is semantic dementia?
A loss of memory for words.
The disorder often starts as problems with word-finding and naming difficulties (anomia), but progresses to include impaired word comprehension and ultimately impaired comprehension of objects as well.
What receptor does LSD act on?
Dopamine
Which SSRI has an increased risk of congenital malformations, particularly in the first trimester?
Paroxetine
What class of drug can induce psychosis?
Steroids
What class of drug is selegiline?
MAOI
What class of drug is amitriptyline?
TCA
In what conditions is ECT indicated?
(4)
1) Treatment resistant/life threatening depression
2) Catatonia
3) Severe mania
4) An episode of moderate depression know to respond to ECT in the past
When is the peak incidence of seizures following alcohol withdrawal?
36 hours
Describe the different categories of depression in the PHQ-9
0-4 –> No depression identified
5-9 –> Mild depression
10-14 –> Moderate depression
15-19 –> Moderately severe depression
20-27 –> Severe depression
Which SSRI is the most likely to lead to QT prolongation and Torsades de pointes?
Citalopram
Is CBT indicated in schizophrenia?
Yes - indicated for all people with schizophrenia
What test is used to assess whether there is need for a specialist evaluation concerning alcohol consumption?
Alcohol Use Disorders Identification Test (AUDIT)?
What scoring system can be used to assess alcohol withdrawal severity?
Clinical Institute Withdrawal Assessment (CIWA-Ar)
Mx of hypomania in 1ary care?
Routine referral to CMHT
Mx of mania?
consider stopping antidepressant if the patient takes one
consider starting antipsychotic therapy e.g. olanzapine or haloperidol
How can lithium cause hypercalcaemia?
Due to hyperparathyroidism
1st line mx of Wernicke’s?
Pabrinex (NOT chlordiazepoxide)
Mx of phobias?
CBT
What is an alternative to lithium in mx of bipolar disorder?
Sodium valproate
Mx of LBD?
Can use acetylcholinesterase inhibitors (e.g. donepezil, rivastigmine) and memantine.
Mx of hypomania?
Same as mania (i.e. antipsychotics)
If on an antidepressant, stop it and start antipsychotic.
What is malingering?
Manufactering or exaggerating symptoms for a purpose OTHER than the sick role:
- financial gain (e.g. compensation)
- evading police
- obtaining shelter
- obtaining drugs e.g. morphine
Define perinatal period
From getting pregnant up to 12m after giving birth.
When do the baby blues peak?
3-5th day postnatal
Which diagnosis makes a woman most likely to experience postpartum psychosis?
Bipolar type 1
What condition can antipsychotics increase the risk of in the mother?
Gestational diabetes
What is the most common medical complication of pregnancy?
Depression
Mx of more severe OCD?
SSRI + CBT (including ERP)
What receptors do opioids bind to?
Mu-opioid receptors
What receptor does LSD mainly bind to?
Serotonin (5-HT3)
1) Is there a possibility of illicit use on top of methadone use?
2) Is there a possibility of illicit use on top of buprenorphine use?
1) Yes
2) No - due to partial antagonist effect
What does disulfiram inhibit?
Aldehyde dehydrogenase
Results in increased serum aldehyde
MOA of MDMA?
Blocks serotonin reuptake
MOA of cocaine?
Blocks monoamine reuptake (increased dopamine, serotonin & noradrenaline)
1st line mx of delirium tremens?
Oral lorazepam
What drug is an opiate blocker that is used in alcohol detox?
Naltrexone
Key side effect of methadone?
QTc prolongation
What are 3 contraindications for disulfiram?
1) heart disease
2) psychosis
3) those at high risk of suicide
What is the role of naltrexone in alcohol detox?
Opiate blocker, makes alcohol less enjoyable and less rewarding.
Initial dose of naloxone given IV in opioid overdose?
400 micrograms
Role of acamprosate in alcohol detox?
Increases GABA and decreases glutamate –> anti-craving
Who is naltrexone contraindicated in? (2)
1) opioid use
2) liver failure
How long should patients avoid alcohol before and after taking disulfiram?
24h before
1 week after
How can you calculate how many units there are in an alcoholic drink?
Units = % (ABV) x volume (ml) / 1000
What receptor does THC bind to?
CB1 receptors
Once detox is complete, what drug can be used to prevent opiate relapse?
Naltrexone
Side effects of zopiclone?
- agitation
- bitter taste in mouth
- constipation
- decreased muscle tone
- dizziness
- dry mouth
- increased risk of falls (especially in the elderly)
Zopiclone withdrawal symptoms?
- convulsions
- tremor
- hyperventilation
1st line for acute stress disorder?
Trauma-focused CBT
How can OCD be differentiated from psychosis?
By the level of insight into their actions
What is the most common endocrine disorder developing as a result of chronic lithium toxicity?
Hypothyroidism
What should you do if you clozapine doses are missed for >48h?
Dose will need to be restarted again slowly (i.e. re-titrated)
Who should all patients with OCD with severe functional impairment be referred to?
2ary care mental health team - treatment (SSRI) can be started whilst waiting for assessment.
