Pharmacology of Anti-Depressant Medication Flashcards
What is the mechanism of action of SSRI’s
selective serotonin reuptake inhibitors
Selectively inhibit the reuptake of serotonin from the synaptic cleft, increasing the concentration of synaptic serotonin
Give some examples of SSRI’s
Fluoxetine Sertraline Citalopram Paroxetine Escitalopram
List the common side effects of SSRI’s
Anxiety Agitation Nausea Headache GI upset Sexual dysfunction >risk of suicide in <25y/o
What side effect of SSRI’s is a problem in the elderly?
Hyponatraemia
What time of day should SSRI’s be given and why?
Morning
Can have insomnia effects
Which SSRI has the most severe discontinuation effect?
Paroxetine
What neurological illness can SSRI’s negatively impact?
Epilepsy
They can increase occurrence of seizures
What is the mechanism of action in Tricyclic antidepressants?
(TCA’s)
Block the reuptake of monoamines, mainly 5-HT and noradrenaline, at the presynaptic terminals
They act on a multitude of terminals unlike SSRI’s
List some examples of TCA’s
Amitriptyline Clomipramine Imipramine Lofepramine Dusolepin
What can TCA’s treat
Depression (especially effective if insomnia) (usually not first line due to S/E's) OCD Anxiety Migraine prophylaxis Neuropathic Pain Nocturnal Enuresis
List some common side effects of TCA’s
Anti-cholinergic effects Sedation Weight gain Arrhythmias Cardiotoxic Postural Hypotension Seizures
Name a more selective TCA
Clomipramine
Only acts on 5-HT terminals
What patients should you avoid prescribing a TCA
Those with high suicidal risk
TCA’s are VERY toxic in an overdose
Describe the mechanism of action in monoamine oxidase inhibitors? (MAOI’s)
These work by acting on the enzyme monoamine oxidase, to prevent the breakdown of monoamines in the presynaptic cleft. This increases the monoamine concentration.
MAOI’s can be irreversible or reversible
Give some examples of an MAOI
Phenelzine
Tranylcypromine
Moclobemide
What serious reaction must patients be warned about when taking MAOIs.
“Cheese reaction”
MAOIs interact with tyramine foods e.g. cheese, red wine, herring, game etc which can cause a hypertensive crisis
Which anti-depressants must you discontinue before you put a patient on MAOI
SSRIs and TCAs
List some other side effects of MAOIs
Insomnia
Postural Hypotension
Peripheral Oedema
When are MAOIs used to treat depression?
3rd Line after SSRIs and TCAs
Describe the mechanism of action is SNRI’s
serotonin and noradrenaline reuptake inhibitors
These drugs act on the persynpatic terminals to block the reuptake of noradrenaline and 5-HT but they lack major receptor blockings unlike TCA’s so have less effect
Give some examples of SNRI’s
Venlafaxine
Duloxetine
What are some of the side effects of SNRI’s
NO CHOLINERGIC EFFECTS
Insomnia
Cardiac arrhythmias
Similar to SSRIs but more severe
What can duloxetine also treat
Neuropathic pain and bladder instability
Which anti-depressant drug works well alongside SNRI’s as a dual therapy?
Mirtazapine
What class does mirtazapine fall into?
NaSSA
Noradrenaline and Specific serotonergic antidepressant
What is the mechanism of action for NaSSA
It increases the activity of noradrenaline and 5-HT by blocking receptors in the negative feedback loops
When is mirtazapine used first line for depression?
When patient also suffers from insomnia and/or poor appetite
Mirtazapine should be taken at night. True/False
True.
It has extreme drowsiness effects
List some side effects of mirtazapine (NaSSA)
Hunger and weight fain Drowsiness Constipation Dizziness and falls Dry moth Weird dreams GI Upset when taken with alcohol
Which drugs should SNRIs NOT be given alongside
MAOI’s
What drug class is buproprion?
Dopamine Uptake inhibitor
