Midterm 2: Antidepressants Flashcards
Fast NT receptors
GABA, 5ht-3, ampa
Slow nt receptors
Noradrenaline and 5ht
Monoamine hyp
depression is due to a deficiency in one or more of 3 catecholamines (seratonin, DA, NE)
monoamine oxidase inhibitors (classical)
-phenylzine, tranylcypromine
-non selective, irreversible
-severe interactions with food and drugs(e.g. tyramine in cheese,beer,liver )
Monoamine oxidase inhibitors: general
-inhibit the destruction of catecholamines DA, Seratonin, NE
tyramine effect
-with MAO type a
-tyramine increases release of NE
-MAO a slows degradation of NE
-causes increased blood pressure
-tyramine levels increase with addition of mao inhibitors b/c tyramine is metabolized by mao in liver
MAO A inhibitors
-inhibit MAO A type enzyme
-A type degrades NE and 5HT (depression)
-moclobemide
-reversible, competetive
-no tyramine effect
MAO B inhibitors
-MAO B is involved in met of DA
-parkinsons treatment
5HT/Seratonin receptors distribution w/n
-widespread
MAO inhibitors neg effects
-tyramine effect
-seratonin sickness
seratonin sickness
-too much 5HT
Tricyclic antidepressants
-imipramine, amatriptyline
-block reuptake of NA, 5HT, and DA
Tricyclic antidepressants side effects
-inhibition of histiminic stimulation
-inhibition of cholinergic stimulation
- inhib of adrenergic stim
auto vs hetero receptors
-autoreceptors are receptors activated by NT released by the neuron
-heteroreceptors are receptors for a monamine different from the NT released by the neuron
SSRIs
-fluoxetine, paroxetine, sertaline, citalopram
-blocks reuptake at dendrites and axon terminal
-lower chance of OD
SSRI progression of effects
-initial increase of 5ht in cell body and dendrites
-autoreceptors cause decrease in 5ht release
-eventual downreg of these receptors and disinhibiton of 5ht release at axon terminals
-increased release of 5ht
-
Neurogenic hypothesis
-postsynaptic seratonin receptors eventually downregulate in response to increase 5ht, decreasing the positive effects of antiDs
-observed mental health does not dip proportionally
-hyp is that neurogenesis occurs somewhere along the way and this stops decline in mental health no pre medication levels
SSRIs neg effects
-disturbed circ rhythm due to reduced melatonin produced in pineal
-nausea, anorexia, sex dysfunction, suicidal thoughts
NDRIs
-noradrenaline/dopamine reuptake inhibitor
-block reuptake of these monamines
-buproprion
-smoking cessation
SNRIs
-Seratonin-noradrenaline reuptake inhibitors
-also some da
-venlafaxine
-
SNDIs
-seratonin norepinephrine disinhibitors
-block neg feedback of these NTs by antagonising alpha 2 receptor
-increased release
5ht receptor types
5ht1d: presynaptic and dendrytic autorecptor
5ht1a and 5ht2a,b: post synaptic stimulatory receptor
5h2c postsynapic heteroreceptor
Effects of activation 5ht types
5ht2a and 5ht2c: insomnia, sex dys, anxiety
5ht1a: antidepressant, anxiolytic, pro-cognitive
Mirtazapine
-SNDI
-NaSSA
-blocks adrenergic alpha 2 autoreceptor, +NE
-blocks adrenergic alpha 2 heteroreceptor on setatonergic neurons, +seratonin
-blocks 5ht receptors that normally have neg effects 2c, 2a, 2c, 3
