Antidepressants and Antipsychotics Flashcards
What are some common effects of adrenergic receptor agonism?
Sweating
Tremor
Headaches
Nausea
Dizziness
What are some common effects of muscarinic receptor agonism?
Dry mouth + thirst (+dysphagia)
Urinary retention/difficulty urinating
Hot and flushed skin
Dry skin
What are some common effects of histamine receptor agonism?
Dry mouth
Drowsiness
Dizziness
N+V
What neurotransmitter system do most anti-depressants act on?
Serotonin
What do most serotonin related anti-depressants aim to do?
Increase serotonin activity at post-synaptic receptors
How long can it take for most anti-depressants to begin working?
2-3 weeks
What is the most commonly used type of anti-depressant?
SSRI’s (Selective serotonin re-uptake inhibitors)
What are some other types of ant-depressant’s?
NSRI’s (noradrenaline and serotonin re-uptake inhibitors)
Mirtazapine
Tricyclics
MAOI’s (Mono-amine oxidase inhibitors)
How doe SSRI’s exert their effects?
By increasing serotonin activity at post-synaptic receptors
How do SSRI’s increase serotonin activity?
Reducing the pre-synaptic re-uptake of serotonin after its release
What does the reduction of the pre-synaptic re-uptake of serotonin result in?
More serotonin sitting in the nerve junction
Other than increased serotonin in the nerve junction, what effect do SSRI’s have on the nerve junction?
Down regulates post-synaptic serotonin receptors
What are some common side-effects of SSRI’s?
Restlessness and agitation on initiation Nausea/GI disturbances Headaches Weight changes Sexual dysfunction
Bleeding and suicidal ideation (less common and usually age related)
What are some examples of SSRI’s?
Sertraline
Citalopram
Escitalopram
Fluoxetine
Paroxetine
What is the dose range for sertraline?
50 - 200mg
In the context of what group of non-psychiatric conditions is sertaline considered the safest?
Cardiac disease
What is the dose range for citalopram?
20 - 40mg
What is the dose range for escitalopram?
10 - 20mg
What must be considered when prescribing citalopram/escitalopram?
QTc prolongation
What is the dose range for fluoxetine?
20 - 60mg
What must be considered when switching from fluoxetine?
Serotonin syndrome
What is the dose range for paroxetine?
20 - 60mg
What must be considered when stopping paroxetine?
Discontinuation syndrome
What does NSRI stand for?
Noradrenaline and serotonin re-uptake inhibitors
How do NSRI’s work?
The same way as SSRI’s but by binding to noradrenaline re-uptake receptors as well
What other symptom are NSRI’s indicated for besides depression?
Neuropathic pain
In what way do the side-effects differ from those of SSRI’s?
Have a greater potential for sedation, nausea and sexual dysfunction
What are the two NSRI’s?
Duloxetine
Venlafaxine
What is the dose range for duloxetine?
60 - 120mg
What is the dose range for venlafaxine?
75 - 375mg
Why is venlafaxine generally better than duloxetine?
More efficacious
Can go to a higher dose
When can high dose duloxetine be problematic?
Heart disease
What must be done regularly in patients on venlafaxine at doses higher than 225mg?
Blood pressure monitoring
What class does mirtazapine belong to?
A unique class
How does mirtazapine work?
By acting as a 5HT-2 and 5HT-3 antagonist
Through what pathway does mirtazapine exert it’s main side effect of sedation?
H1 (histamine) activity
What are the two major side effects of mirtazapine?
Sedation and weight gain
Are the side-effects of mirtazapine always negative?
No - can be used to therapeutic advantage
Are tricyclics antidepressants commonly used?
Not as a first line treatment
When are tricyclics antidepressants usually used?
In patient’s who do not respond to SSRI’s
What are some newer tricyclics antidepressants?
Lofepramine and nortriptyline
What is an older tricyclic antidepressant?
Amitriptyline
What sort of side-effects can tricyclic antidepressants have?
Muscarinic and histamine
Why must caution be taken when prescribing tricyclic antidepressants?
They can be fatal in an overdose
How can tricyclic antidepressants cause death?
QTc prolongation and arrhythmias
What other condition can tricyclic antidepressants be used to treat?
Neuropathic pain
What does MAOI stand for?
Monoamine oxidase inhibitor
What are the two types of MAOI?
MAOI-A and MAOI-B
What pathway do MAOI-A’s work more on?
Serotonin
What pathways do MAOI-B’s work more on?
Dopamine
What type of depression are MAOI’s more useful in?
Atypical depression
What other way can MAOIs be categorised?
Reversible and irreversible
Which category of MAOI’s (reversible or irreversible) are more dangerous?
Irreversible