Pharmacology of antidepressants and mood stabilisers Flashcards
What are the clinical uses of antidepressant drugs?
Moderate/severe depression Dysthymia GAD Panic disorder OCD PTSD Premenstural dysphoric disorder Bulimia nervosa Neuropathic pain
What is included in the monoamine reuptake inhibitor group of drugs?
Tricyclics
SNRIs
SSRIs
What are the three classes of antidepressant drugs?
MOI (monoamine oxidase inhibitors)
MRI (monoamine reuptake inhibitors)
Atypical drugs (post-synaptic receptor effects)
What are the two hypotheses why antidepressant medication lead to similar response?
1-Monoamine hypothesis
2-Neurotransmitter receptor hypothesis
What is noradrenaline responsible for?
Arosal, emotion
What is serotonin responsible for?
Mood, sleep ,feeding, behaviour and sensory perception
What is the typical half-life of antipsychotics?
Months
Why do you tend not to combine antidepressants?
Clinically actions very similar therefore you just get more SE
If SSRI alone for treatment of depression is not working what is added in?
Mirtazapine
TRUE/FALSE
In general the more severe the depression the more effective the antidepressant
TRUE
What drug is St Johns wort similar to?
MOI inhibitor
St Johns wort can interact with the OCP and reduce its efficacy TRUE/FALSE
TRUE
In what type of depression is MOI inhibitors considered?
Anergic bipolar depression
Name two MOI inhibitors and their mode of action
Phenelzine- Irreversible
Moclobemide-Reversible
…inhibitors of MAO
What can you not eat/drink when on MOI inhibitors?
Cheese
red wine/alcohol free beer
gravy, venison, game
Large amounts of caffeine
What biologically is the hypertensive crisis caused by?
Inhibition of MAO-O in gut (&liver) by irreversible inhibitors preventing breakdown of dietary tyramine
As tyramine is a potent releaser of norepinephrine –> Elevated BP
What is hypertensive crisis due to tyramine treated with?
Phentolamine infusion
TRUE/FALSE
MOI inhibitors can potentiate other drugs by decreasing their metabolism
TRUE
S/E of MOI inhibitors
Insomnia
Peripheral oedema
Postural hypotension
What type of pain are tricyclics used in?
Neuropathic
What is our fav tricyclic?
Amitriptyline
How do tricyclics work?
Block the reuptake of monoamines into presynaptic terminals
What are the SE of tricyclics?
Anticholinergic
Sedation (if drowsy don’t drive)
Wt gain
Cardiovascular
Are tricyclics cardiotoxic in overdose?
Yes
What is the only licences SSRI for <18?
Fluoxetine
Which is the best SSRI?
Escitalopram
Which SSRI is safest in cardiac problems?
Sertraline
Which SSRI is safest in epilepsy?
Citalopram
Which are the two classes of antidepressants that are taken at night because they are sedating?
TRICYCLICS (amitriptyline)
NASA ( mirtazapine)
What are the common SE of SSRIs?
Headache Nausea GI upset Sweating/vivid dreams/anxiety Confusion/dizziness Sexual dysfunction
What is there a risk of when on fluoxetine and drinking high amounts of caffeine?
Serotonin syndrome
If prescribe someone with anxiety an SSRI transiently what will there be?
An increase in anxiety
What is often a cause of admission of elderly patients as a result of being on an SSRI?
Hyponatraemia
Why should SSRIs not be given to young people?
Risk of suicidal thoughts (however much safer in overdose)
What are two examples of SNRIs?
Venlafaxine
Duloxetine
What are three uses of Duloxetine?
Depression
Neuropathic pain
Bladder instability
How do SNRIs work?
Block the reuptake of monoamines into presynaptic terminals
What is the important SE of SNRIs?
Hypertension/cardiac arrhythmias
In theory when would mirtazapine be used 1st line in depression?
If patient has insomnia and poor appetite
Why is mirtazapine often added into other treatments?
Reduce the sick/headaches S/E
