Psychopharmacology

Question 1

What is the monoamine hypothesis of depression?

Answer 1

Due to decreased:

• Seretonin
• Dopamine
• Noradrenaline

Question 2

Give generic examples of some anti-depressants and explain them

Answer 2

• TCA = TRICYCLIC ANTIDEPRESSANT (e.g. Trazodone)
  
  • Block serotonin and noradrenaline re-uptake, increasing noradrenergic and serotinergic neurotransmission
• SSRI = SELECTIVE SEROTONIN REUPTAKE INHIBITOR (e.g. sertraline, citalopram, fluoxetine)
  
  • Block serotonin re-uptake, increasing serotinergic neurotransmission
• SNRI = SEROTONIN / NORADRENALINE REUPTAKE INHIBITOR (e.g. Venlafaxine)
  
  • Block serotonin, noradrenaline (and dopamine?) re-uptake, increasing serotinergic and noradrenergic neurotransmission
• NaSSA = NORADRENALINE & SPECIFIC SEROTINERGIC ANTIDEPRESSANT (e.g. mirtazapine)
  
  • Block pre-synaptic alpha2-adrenoceptors, increasing noradrenergic and serotinergic neurotransmission
• MAOI = MONO-AMINE OXIDASE INHIBITOR (e.g. phenelzine)
  
  • Block enzymatic breakdown of noradrenaline, serotonin, dopamine and tyramine, increasing neurotransmission

Question 3

Advantages and notes of anti-depressants

Answer 3

Question 4

What to be aware of when prescribing antidepressants?

Answer 4

• All antidepressants are associated with a risk of increased suicidal thoughts and ideation during the first few weeks of treatment.
• Risk of hyponatraemia due to inappropriate secretion of ADH – particularly in elderly and with SSRIs
• Other indications:
  
  • Anxiety disorders (SSRIs, venlafaxine)
  • Obsessive Compulsive Disorder (SSRIs, clomipramine)
  • Panic disorder (SSRIs)
  • Eating disorders (fluoxetine)
  • Neuropathic pain (TCAs)
  • Migraine prophylaxis (amitriptyline)
  • Nocturnal enuresis (imipramine)

Question 5

Dopamine levels and symptoms in schizophrenia

Answer 5

• Increased dopamine causes positive symptoms of schizophrenia
• Decreased dopamine causes negative symptoms of schizophrenia

Question 6

Give some examples of anti-psychotic drugs

Answer 6

FIRST GENERATION

• Oral
  
  • Haloperidol
• Depot
  
  • Haloperidol

SECOND GENERATION

• Oral
  
  • Clozapine
  • Olanzapine
  • Risperidone
• LAIs
  
  • Olanzapine
  • Risperidone

Question 7

How do first and second generation antipsychotics work?

Answer 7

First generation antipsychotics:

• Act predominantly by blocking DOPAMINE D2 receptors
• Are not selective for any of the four dopamine pathways in the brain, therefore cause a range of side-effects, e.g. EPSE, elevated prolactin

Second generation antipsychotics:

• “Atypical antipsychotics”
• Act on a range of receptors, including SEROTONIN receptors
• More distinct clinical profiles, particularly with regard to side-effects

Question 8

Why isnt clozapine used as much?

Answer 8

• Most effective antipsychotic – why don’t we it for everyone?
  
  • Hypersalivation
  • Hyperthermia
  • Tachycardia
  • Constipation
  • Seizures
  • Myocarditis
  • Agranulocytosis

ALSO…

• Mandatory blood monitoring for neutropenia and agranulocytosis (CPMS)
• Fatalities from bowel impaction
• Only available from specialist prescribers/registered pharmacies

Question 9

What needs to be done before someone is put on an antipsychotic?

Answer 9

• A baseline ECG is recommended before initiating any antipsychotic and continued monitoring is advised, including repeat ECGs at dose changes and at regular review
  
  • U&Es, FBC, lipid profile, Glucose (fasting if possible) or HbA1c, TFTs, LFTs, Prolactin, CK, Weight, BP

Question 10

Why are anti-muscarinics prescribed with antipsychotics?

Answer 10

• For antipsychotic-induced parkinsonism/EPSEs:
  
  • Procyclidine
  • Trihexyphenidyl
  • Orphenadrine
• For hypersalivation:
  
  • Hyoscine hydrobromide – patches or sublingual tablets

Question 11

Explain the difference between depression and bipolar (brief)

Answer 11

Question 12

What drugs are used for bipolar disorder and mania?

Answer 12

• Acute phase:
  
  • Benzodiazepines, e.g. lorazepam – short term
  • Antipsychotics, e.g. quetiapine, asenapine
• Mood Stabilisers for long-term management:
  
  • CARBAMAZEPINE
  • VALPROATE – as valproic acid or sodium valproate
  • LAMOTRIGINE
  • LITHIUM (mood stabiliser)

Question 13

Explain lithium

Answer 13

• Most effective long-term treatment option
• Narrow therapeutic index – prescribe by brand name
• Close monitoring required – Trust lithium registers
  
  • Lithium levels (target range 0.6-0.8 mmol/litre) – weekly until stable, then every 3 months - take sample 12 hours after last dose
  • eGFR/U&Es, TFTs, weight, calcium – baseline, then every 6 months
• Signs of toxicity (>1.0 mmol/litre) – loss of appetite, nausea, diarrhoea, muscle weakness/twitching, drowsiness, coarse tremor, ataxia
• Levels <0.6mmol/litre – check timing of sample; adjust dosage if correct and recurrent
• Interactions – NSAIDs, thiazide diuretics, ACE inhibitors

Question 14

Give examples of hypnotics

Answer 14

Benzodiazepines

• TEMAZEPAM (short-acting)
  
  • Act at receptors associated with GABA (inhibitory transmitter)
  • High potential for dependency

Z drugs (are new drugs)

• Zaleplon

Question 15

Give examples of anxiolytics

Answer 15

Benzodiazepines

• DIAZEPAM
  
  • Long-acting
• LORAZEPAM
  
  • Short-acting

Others

• Pregabalin
  
  • Antiepileptic

Question 16

What are some drugs for dementia?

Answer 16

• Mild to moderate Alzheimer’s disease:
  
  • Acetylcholinesterase inhibitors:
    
    • Donepezil – 1^st linel
    • Rivastigmine / Galantamine – 2^nd line
• Severe Alzheimer’s disease (or if AChEi not tolerated):
  
  • MEMANTINE
    
    • Glutamate receptor antagonist
• Behavioural and psychological symptoms:
  
  • AChEi’s
  • Memantine
  • Antipsychotics
  • Antidepressants
  • Benzodiazepines

Question 17

What are some memory drugs (for dementia)? & side effects

Answer 17

• Acetylcholinesterase inhibitors
  
  • Prevents acetylcholinesterase from breaking down acetylcholine
  • Licensed for mild to moderate Alzheimer’s
• Side effects : loss of appetite, nausea and vomiting diarrhoea, dizziness, bradycardia, insomnia.

Question 18

Explain memantine and when it is used & side effects

Answer 18

• Used in severe Alzeihmer’s
• Is a glutamate receptor antagonist
• Side effects
  
  • Constipation
  • Hypertension
  • Dyspnoea
  • Dizziness

Question 19

Explain substance dependence drugs to prevent it

Answer 19

• Alcohol
  
  • Acamprosate
    
    • GABA agonist/glutamate antagonist
  • Disulfiram
    
    • Inhibits alcohol oxidation
  • Nalmefene
    
    • Opioid receptor antagonist/partial agonist
• Opioids
  
  • Buprenorphine
    
    • Opioid receptor partial agonist
  • Methadone
    
    • Opioid substitute
  • Naltrexone
    
    • Opioid receptor antagonist
• Nicotine
  
  • Nicotine
    
    • Nicotine substitute

Question 20

Explain rapid tranquilisation & what drugs to use

Answer 20

Drugs

• Lorazepam IM
• Haloperidol IM

When to do?

• Only when detained patient
• Presents as a risk to them and/or others
• When refusing meds
• When de-escalation techniques fail
• Used as a last resort to ensure safety
• Regular monitoring and full documentation required

Question 21

Dosage of drugs when would they change?

Answer 21

• Smaller doses should be given to older patients (especially with rapid tranquillisation
• With age and chronic illness, liver size and hepatic blood flow are DECREASED, therefore dosing of medications that are significantly metabolised by the liver should be adjusted.

Question 22

What are some CNS stimulants & ADHD meds and risks

Answer 22

• Give amphetamines
  
  • Work by increasing dopamine levels
  • E.g. atomexetine
  • Potential for misuse and diversion
  • Can affect growth and physical development (in young) → monitoring weight and height required
  • Cardiovascular effects → monitor BP and pulse

Question 23

Questions to answer

Answer 23

• Bipolar- Strategy for medication in different phases
• Medication vs psychological therapies
• Side effects of medication, are they worth it?
• CAMHS: when to medicate or not?
• Antipsychotics: how do they work?
• How, when and why follow up for different medication (include Clozapine and Lithium)•Dealing with hindering factors (stigma, compliance)