SNRIs Flashcards
(9 cards)
SNRI’s are
non-TCA: they target SERT and NET but don’t affect Na+ channels or muscarinic receptors so fewer SE than TCA’s
They are known as ‘dual action’ but also act on DA in prefrontal cortex.
NET also takes up DA so NET-I’s can increase levels of both NTs
SNRI’s are alternative treatments for…
chronic pain syndromes: fibromyalgia, peripheral neuropathy, MS
This is due to blocking of NE re-uptake
SNRI Agents/medications
Venlafaxine Milnacipran
Desvenlafaxine Levomilnaciprine
Duloxetine
SNRI significant side effects
More GI upset than SSRIs, sexual dysfunction
Venlafaxine - dose related hypertension
Duloxetine - has anti-muscarinic activity –> dry mouth, nausea, constipation, insomnia, diaphoresis
Venlafaxine: mechanism of action/general info
used most for anxiety d/o’s
has varying degrees of SER-I (most potent of SNRI’s) vs NE re-uptake (only robust at high dosees)
No significant action on other receptors.
NET-I likely accounts for sweating, HTN
Desvenlafaxine: mechanism of action/gen info
This is the active metabolite of Venlafaxine from CYP450 2D6
Has more NET-I relative to SERT-I
CYP450 metabolism - so inhibits other meds, people who are poor metabolizers or w/ genetic polymorphisms that make venlafaxine so variable have more predictable results with Desvenlafaxine
Duloxetine: mechanism of action/gen info
SERT-I is slightly more potent than NET-I: this med proved psychic pain is not somatic pain
Treats depression in the absence of pain and pain in the absence of depression.
Shown efficacy in tx of cognitive sx prominent in elderly: possibly r/t pro-noradrenergic/dopamenergic NET-I
Milnacipran: mechanism of action/gen info
NET-I > SERT-I: only approved for tx of Fibromyalgia in US
Increased NET-I has favorable profile for cognitive sx (fibro fog) and is also more energizing/activating than other SNRIs, but causes increase SE (sweating, urinary hesitancy - from pro-adrenergic actions at alpha1 receptors in bladder)
