Psychopharamcology Flashcards
What is the action of serotonin?
Stabilises mood, feelings of well being and happiness, enables brain cells and other nervous system cells to communicate with each other
Helps with sleeping, eating, and digestion
What is the action of NA?
Increases arousal and alertness
Enhances formation and retrieval of memory and focusses attention, increases restlessness and anxiety
What is the action of dopamine?
Released when brain is expecting a reward and associated with reward
Why are MAO inhibitors rarely used?
Due to S/E
What is the mechanism of action of MAO inhibitors?
MAO enzyme works in gut to aid tyramine breakdown and down and works in brain to remove NA, serotonin and dopamine
Inhibitors prevent MAO working and so prevent the removal of NA, serotonin and dopamine from the brain
What are the S/E are MAO inhibitors?
Cheese effect - lack of breakdown of tyramine rich foods such as aged cheese, beer, dried meats, red wine - leads to migraines and life threatening BP spikes
Drug interactions - nasal decongestants, salbutamol and many more
Give 2 examples of MAO inhibitors
Isocarboxazid
Phenelzine
How do TCAs work?
Blocks 5-HT and NA transporters therefore blocking reuptake of serotonin and NA in presynaptic terminals therefore increasing mood and focus
Non-specific
Why are TCAs often not used?
S/E
Worse in an overdose
Give 2 examples of TCAs
Amitriptyline
Clopipramine
Nortriptyline
What are the S/E of TCAs?
Anticholinergic effects - can’t pee, can’t see, can’t spit, can’t shit
Alpha-1 adrenergic antagonism
- Antihistaminergic (H1) - sedation, weight gain
Overdose, seizures (lowers seizure threshold)
More likely to have a cardiac arrest
Give 2 examples of SSRIs
Citalopram
Fluoxetine
Sertraline
Why are SSRIs preferential?
Fairly safe in overdose
Fewer S/E
How do SSRIs work?
Blocks serotonin reuptake
What are SSRIs used for?
Depression GAD PTSD Eating disorders OCD
What are the S/E of SSRIs?
Nausea, headache, GI upset (5-HT3)
Agitation, akathisia, anxiety, sexual dysfunction, insomnia (5-HT2)
S/E tend to wear off after a few weeks
Give 2 examples of SNRIs
Duloxetine
Venlafaxine
Give 2 examples of antipsychotics
Risperidone
Olanzapine
Clozapine
How do antipsychotics work?
Inhibit dopaminergic neurotransmission (D2)
Block D2 receptors in the meso-limbic system - reduces positive symptoms of psychosis BUT they feel less pleasure and have less ability to feel pleasure (meso-limibic system is activated by drugs
Block D2 receptors in the meso-cortical pathway - decreases the negative symptoms of psychosis - more control over emotions
What are the S/E of antipsychotics and why do they occur?
Also block D2 receptors in nigrostriatal pathway leading to a reduction in movement
Motor - acute dystonia, akathisia, tardive dyskinesia
Hyperprolactinaemia - infertility, irregular/no periods, galactorrhoea, pain in breasts, loss of libido, increased risk of ovarian and breast cancer
Metabolic - increased appetite and weight gain
Hypertriglyceridaemia
Lower seizure threshold
Postural hypotension
What is the first line treatment for depression?
SSRIs
SNRIs second line
How does mirtazapine work?
Antagonist effects on central presynaptic alpha-2 adrenergic receptors causing an increased release of serotonin and noradrenaline
Why is mirtazapine given to older adults?
Fewer drug interactions
What is the S/E of mirtazapine?
Weight gain
What are the S/E of SSRIs?
Initially nausea, vomiting, anxiety, weight loss, diarrhoea, insomnia
Sexual dysfunction may persist
What are the S/E of TCAs?
Postural hypotension Blurred vision Urinary retention Constipation Dry mouth Weight gain Drowsiness Confusion Agitation Adverse effects on cardiac function
What are the S/E of SNRIs?
Nausea, sexual dysfunction, headache, insomnia, anxiety and sweating
Dose related increased in BP
What are the S/E of MAOIs?
Postural hypotension/dizziness
Constipation
Interactions with foods
What are the discontinuation symptoms of anti-depressants?
GI disturbances Headache Anxiety Dizziness Paraesthesia Electric shock sensation in head, neck and spine Tinnitus Sleep disturbances Fatigue Flu like symptoms Sweating
What are first generation anti-psychostics?
Typical
Purely block D2 and cause extra-pyramidal S/E causing movement disorders
What are second generation anti-psychotics?
Atypical
5-HT2a occupancy too meaning you get some dopamine and extra-pyramidal S/E are reduced
Name a S/E of aripiprazole?
Get constant agitation
Unable to feel settled
What are the complications of anti-psychotic S/E?
Physical health complications - require full yearly health checks - ECG, weight, waist circumference
Confound assessment of clinical condition
Too much can make them seem psychotic
Functional impairment - sedation levels
Social stigma
Negative attitudes towards treatment
Name 3 mood stabilisers
Lithium Olanzapine Lamotrigine Carbamazepine Sodium valproate
What does lithium work for?
Mania and depression but better for mania
What does olanzapine work for?
Mania/manic episodes
What does lamotrigine work for?
Bipolar if bipolar is mainly depressive episodes
What does carbamazepine work for?
Not NICE recommended
Bipolar
But only when bipolar is unresponsive to lithium
What does sodium valproate work for?
Mania and depression
Not as good as lithium
Better for mania
What are the S/E of lithium?
Fine tremor Sedation Lethary Impaired coordination Gastric disturbances Polyuria Weight gain Oedema Hypothyroidism
What are the S/E of valproate?
GI pain Drowsiness Tremor Ataxia Sedation Hair loss Increased appetite Weight gain Blood dyscrasias (low white cells, liver damamge)
What are the S/E of lamotrigine?
Headache Drowsiness Nausea Diarrhoea Ataxia Tremor Blurred vision Skin rash Blood disorders Liver failure
What are the S/E of carbamazepine?
Fatigue Nausea Blurred vision Ataxia Headache Drowsiness Rare - blood, liver, and skin disorders potentially serious in nature
What do you need to monitor with lithium and how long for?
Thyroid function - at start and every 6m
Calcium - at start and every 6m
Renal function - at start and every 6m
Serum levels - 1 week after initiation, at every dose change, 3m once stable
What do you need to monitor with valproate and how long for?
Liver function - at start and during first 6m
Serum levels - only if evidence of poor effectiveness or toxicity
FBC - at start
What do you need to monitor with carbamazepine and how long for?
Liver function - at start and periodically
Serum levels - only useful in verification of compliance
FBC - at start and periodically
What does the mnemonic LITHIUM stand for?
L - levels 0.6-1.0 mmol/L, leukocytosis (older adults < 1.0)
I - nephrogenic diabetes insipidus (v rare)
T - tremors mild, coarse = toxicity
H - hydration - dry mouth, diarrhoea, thirsty - must drink, NA restricted diet, no diuretics, and NSAIDs, regular renal function tests
I - increased GI, skin, and memory problems
U - under active thyroid
M - metallic taste, mums beware - Ebsteins phenomena
What level does lithium need to be to be determined toxic?
> 1.5 mmol/L
What are the symptoms of lithium toxicity?
N&V Diarrhoea Confusion Excessive sleeping Seizures Myoclonic jerks Coarse tremor
What are the causes of lithium toxicity?
Fluid depletion Changes in salt level in diet Reduced renal function Certain medications (diuretics, NSAIDs, BP medication) Change in brand of lithium
How do you treat lithium toxicity?
Stop lithium
Rehydrate
Consider haemodialysis
What is the problem with valproate?
Highly teratogenic
High risk of developmental abnormalities
Who should you not prescribe valproate to?
Female patients of childbearing age unless only option
How do you look after young women on valproate?
Pregnancy prevention programme
Irreversible/long term forms of contraception
Require a checklist going through yearly
