Antidepressant Drugs Flashcards
What are the main forms of depression?
Major depression, bipolar disorder, dysthymic disorder and depressive disorder (not otherwise specified)
What genetic factors may convey an increased risk of developing depression?
5-HT transporter polymorphisms (serotonin)
Which brain regions are associated with depression?
Amygdala, medial prefrontal cortex, ventral striatum (nucleus accumbens) and hippocampus
What neurotransmitter pathways are implicated in depression?
Noradrenergic and serotonergic
What gross brain changes can be seen in the MRI of an individual with depression?
Reduction in glucose metabolism in the subgenus prefrontal cortex and reduction in the grey matter in this area
How does depression affect the hippocampus?
It causes there to be an increase in neuronal loss and neurogenesis which is thought to lead to an increase in cortisol and pro-inflammatory cytokine release (which can lead to stress-induced illness)
What is the monoamine hypothesis of depression?
In depression there is a reduction in the monamine transmitters (dopamine, serotonin and noradrenaline)
What is rumination?
Recurring, negative thoughts playing in the mind
What brain structures are involved in rumination?
Amygdala and hippocampus
Explain the mechanism of action of tricyclic antidepressants
Inhibit the reuptake of amines (serotonin and noradrenaline) and bind to H1, a1 and a2 receptors –> vasodilation and increased sympathetic outflow
What are the potential side-effect of tricyclic antidepressants?
Dry mouth, constipation, loss of libido
What type of drug are clomipramine and amitriptyline?
Tricyclic antidepressants
Explain the mechanism of action of monamine oxidase inhibitors
Irreversibly bind to MAO to prevent breakdown of monamines (dopamine, serotonin and noradrenaline)
What are the disadvantages of monamine oxidase inhibitors?
Interacts with tyramine-containing food as well as pethidine and sympathomimetic compounds
What is meant by the ‘cheese effect’ of MAO inhibitors?
MAO inhibitors interact with tyramine-containing food (cheese, pickled fish/meat, red wine, beer, yeast)
What is the advantage of MAO inhibitors?
Can treat atypical depression such as anxiety and phobia
What type of drugs are phenelzineu and iproniazid?
MAO inhibitors
Explain the mechanism of action of selective serotonin inhibitors
Inhibits CNS neurone uptake of serotonin
What type of drug are citalopram and fluoxetine?
Selective serotonin receptor inhibitors
What is moclobemide?
A reversible MAO inhibitor
What is venlafaxine?
Serotonin noradrenaline reuptake inhibitor (SNRI)
What is reboxetine?
A noradrenaline reuptake inhibitor (NARI)
What is mirtazapine?
A noradrenrrgic and specific serotonergic antidepressant (NASSA)
Explain the mechanism of action of NASSA drugs
Antagonise central presynaptic a2 receptors (inhibits -ve feedback to nerve and causes increase in NA and 5-HT release)
