SNRI's Flashcards
Give examples of SNRI’s
venlafaxine, desvenlafaxine, levomilnacipran,
duloxetine
What is the action of SNRI’s
Inhibit reuptake of serotonin and norepinephrine
When are SNRI’s used?
May be effective in treating depression in patients whom SSRI’s are ineffective
What are the additional benefits of SSRI’s
Depression may be accompanied by chronic pain eg back pain and muscle aches (against which SSRI’s are relatively INEFFECTIVE). This pain is modulated by serotonin and norepinephrine pathways in the CNS
What do TCA’s and SNRI’s have in common
They are both effective against pain caused by diabetic neuropathy, fibromyalgia and lower back pain
How are SNRI’s different from TCA’s
SNRI’s have little activity on alpha-adrenergic, muscarinic and histamine receptors so have little receptor mediated side effects
What is the mechanism of action of venlafaxine
Potent inhibitor of serotonin reuptake and at medium to higher doses is an inhibitor of norepinephrine reuptake
What are the side effects of venlafaxine?
nausea, headache, sexual dysfunction,sedation
and constipation. Increase in BP and HR at high doses
What is the clinical activity and adverse effect profile of desvenlafaxine
Similar to venlafaxine
What is the mechanism of action of duloxetine?
Blocks reuptake of serotonin and norepinephrine at al doses
How is metabolised?
Metabolised in the liver to inactive metabolites (should be avoided in patients with hepatic impairment
What are the side effects of duloxetine
insomnia dizziness, somnolence, sexual dysfunction
What are the GI side effects of duloxetine
Nausea, dry mouth and constipation
Stopping SNRI’s
SNRI’s may precipitate a discontinuation syndrome if stopped abruptly
