ANS Meds Flashcards
Nervous System divisions
(see chart)
What does the SNS do?
Fight or flight response
ex. dilate pupils/bronchioles, increase HR, constrict vessels
What does the PsNS do?
Rest and digest
SLUDGE
ex. constrict pupils/bronchioles, decrease HR, dilate vessels, increase peristalsis, constrict bladder & dilate sphincter
What does SLUDGE stand for?
Salivation, lacrimation, urination, digestion, GI distress, emesis
PsNS
Define adrenergic, cholinergic, mimetic, agonist, antagonist
- Adrenergic –> sympathetic response, releases adrenaline
- Cholinergic –> parasympathetic response
- Mimetic –> mimics systemic effects
- Agonist –> works with the system to effect a response
- Antagonist –> works against the system to effect a response
How do adrenergics and cholinergics affect the SNS & PNS?
(see picture)
Adrenergic Agonists
- stimulate SNS
- affects Alpha 1 & 2, and Beta 1 & 2 receptors
see individual cards for effects
Alpha 1 Adrenergic agonists
A1 receptors are peripheral
sympathomimetic- turns SNS “on”
- increase cardiac contractility (inotropic), vasoconstriction
- dilate pupils/bronchioles
- increase HR
- increase glucose
- decrease uterine contractions, urination, GI motility
“Fight” response
Good for BP control
Alpha 2 Adrenergic agonists
does opposite of expected
- inhibits norepinephrine release
- promotes vasodilation, decreased BP
- decreased GI motility/tone
Beta 1 Adrenergic agonists
- Beta 1 receptors primarily in heart
- increase cardiac contractility, HR (inotropic)
- increases renin secretion & BP
“one heart”
Beta 2 Adrenergic agonists
- Beta 2 receptors primarily in lungs
- decreases GI tone/motility
- bronchodilation
- increased blood flow in skeletal muscles
- relaxes smooth muscles of uterus
- activates liver glycogenolysis (increases BG)
“two lungs”
ie. Albuterol
Dopaminergic receptors
- located in renal, mesenteric, coronary, and cerebral arteries
- vasodilation
only react to dopamine?
Classifications of adrenergic agonists
- Direct-acting –> directly stimulates adrenergic receptors (ie. epi/norepi)
- Indirect-acting –> stimulates release of norepi from terminal nerve endings (ie. amphetamines)
- Mixed-acting –> stimulates adrenergic receptor sites and release of norepi from terminal nerve endings (ie. ephedrines)
directs are natural, indirects and mixed are synthetic
Catecholamines
- produce sympathetic response
- endogenous (adrenal glands) - epi, norepi, dopamine (brain)
- synthetic - isoproterenol, dobutamine
Noncatecholamines
- stimulates adrenergic receptors
- most have longer duration than endogenous/synthetic
- phenylephrine, metaproterenol, albuterol
Epinephrine
(Adrenaline)
- nonselective adrenergic agonist
- endogenous catecholamine
- inotropic, vasoconstriction, bronchodilation
- monitor for IV infiltration/extravasation (phentolamine mesylate)
Albuterol
- noncatecholamine adrenergic agonist
- bronchodilation
- use cautiously in heart pts
Central-acting alpha 2 agonists
- act on CNS to promote vasodilation
- decreases norepinephrine release & peripheral adrenergic receptor activation
- Clonidine (HTN), methyldopa (version of dopamine)
Adrenergic antagonists
blockers
- blocks alpha and beta receptor sites & effects of adrenergic NTs
- directly by occupying receptor sites, or indirectly by inhibiting release of epi/norepi
Alpha adrenergic antagonists
alpha blockers
- promote vasodilation
- selective - blocks A1
- non-selective - blocks A1 & A2
- -sin ending
remember A2 does opposite
caution in resp issues
Beta adrenergic antagonists
beta blockers
- promote vasodilation (decrease HR & pulse)
- selective - blocks B1, fewer side effects
- nonselective - blocks B1 & B2 receptors –> bronchoconstriction
- -lol ending
caution in resp issues
Adrenergic neuron antagonists
- block release of norepinephrine (& other catecholamines/serotonin)
- decrease BP
ie. reserpine
st. john’s wort decrease effects
What is the neurotransmitter of the PNS?
acetylcholine (ACh)
What are the cholinergic receptors?
muscarinic (smooth muscles & heart) and nicotinic (skeletal muscles)
