anti-depressants Flashcards
describe the monoamine theory
deficits in monoamine neurotransmitters (eg. 5HT and noradrenaline) causes depression. this can be seen when patients took reserpine which inhibits the storage of 5HT and NA in the body, resulting in Sx of depression
what are the limitations of the monoamine theory?
studies of monoamine markers in depressed patients have yielded inconsistent and equivocal results. monoamine hypothesis alone is inadequate to explain all pharmacological actions in depression
name an example of MAOis and their mechanism of action
eg. phenelzine, selegiline, moclobemide
MOA: increase bioavailability of monoamines
ADR of MAOis
postural HoTN caused by dopamine accumulation
restlessness and insomnia
name an example of TCA and their mechanism of action
eg. imipramine, amitriptyline, nortriptyline, desipramine
blocks serotonin & norepinephrine transporters to prevent the reuptake of its substrates
name an example of SSRI and its mechanism of action
prevent reuptake of serotonin at the pre-synaptic terminal
eg. fluoxetine and citalopram
ADR of TCA
sedation, postural HoTN, dry mouth, blurred vision, constipation
ADR of SSRI
nausea and insomnia, sexual dysfunction
what are the advantages of using SSRI over TCAs?
low affinity for alpha adrenoceptors, reducing cardiovascular efffects
lack of effect at histamine receptors. reducing sedation
lower affinity for muscarinic receptors, reducing anticholinergic effects
name an example of a NARI
reboxetine, maprotiline
ADR of NARI
dry mouth, constipation, insomnia due to increased NA, tachycardia
what are some examples of SNRIs?
venlafaxine, desvenlafaxine, duloxetine
ADR of SNRI
nausea, insomnia, sexual dysfunction
has stronger withdrawal effects than SSRI and TCA
what is the MOA of mirtazapine
antagonist of adrenergic alpha-2 autoceptors and 5-HT2 receptor
what is the MOA of bupropion
norepinephrine-dopamine reuptake inhibitor (NDRI)
