Antidepressants Flashcards
What are the tricyclic antidepressants (2)?
Imipramine, Amitryptiline
What are the heterocyclic antidepressants (3)?
Mirtazapine, Venlafaxine, Bupropion
What are the SSRIs (3)?
Fluoxetine, Paroxetine, Sertraline
What are the MAO (monoamine oxidase) inhibitors (1)?
Phenelzine
What is the therapeutic mechanism of antidepressants?
either block NE and/or 5HT uptake or slow the breakdown of them. Therefore, they increase the synaptic concentrations of NE and serotonin
Does relief of depression happen right away?
No! 2-3 week delay even though pharmacological effects occur rapidly
What is the biogenic amine hypothesis?
5-HT1A receptors on presynaptic neurons inhibit firing of serotonin neurons, and both presynatpic alpha 2 adrenoreceptors and presynaptic 5-HT receptors act to inhibit release of serotonin. initially, the transmitters on the receptors of the presynaptic cells provide negative feedback which ooposes the increase in serotonin tone. i.e. in the initial phase of tx, effects of drugs are compensated for by inhibitory elements (less serontonin is released due to inhibition of presynaptic cell!). After extended tx, inhibitory elements desensitize, allowing drugs to have increased post-synaptic effects.
What does chronic stress cause?
Increase of coritosteroids, decreased hippocampal volume, depression
What happens with long term treatment with antidepressants?
upregulation of cAMP signaling through the activation of 5-HT and NE receptors, which produces increased levels of Brain Derived Neurotrophic Factor which reverses the effects of chronic stress.
Do antidepressants affect normal mood?
No. (no euphoria)
How do tricyclic antidepressants work?
they block NE and 5HT uptake
How long does it take to see improvement in mood with tricyclic antidepressants?
2 weeks of tx (risk of suicide during this time). tx should be at least 6-8 weeks.
Do all patients respond to antidepressants? Why/why not?
No. variations in pharmacokinetics, noncompliance, some people just don’t respond (heterogeneous disease)
What are some side effects of tricyclics? Why?
atropine-like sxs: dry mouth, blurred vision, constipation, mild sedation, hypotension and fatigue. these can affect compliance. side effects because they block muscarinic-cholingergic, histaminergic, and alpha-1 adrenergic receptors
How does Venlafaxine work?
inhibits NE and 5HT reuptake without blocking muscarinic-cholinergic, histaminergic, or alpha1 adrenergic receptors like in tricyclics.
What are the side effects of venlafaxine?
tolerated well - side effects similar to SSRI’s: nausea, vomiting, HA, sexual dysfunction
How does Mirtazapine work?
enhances neurotransmission at serotonin receptors by blocking alpha2 adrenergic receptors and presynaptic serotonin receptors. also anxiolytic.