Download Action - Allnurses.com

Alpha-Adrenergics
Sympatomimetics
Action:






Norepinephrine is considered the parent or prototype drug
produce effects almost identical to those of norepinephrine
major effect is contraction of smooth muscle
vasoconstriction of most blood vessels
contraction of sphincter muscles in the GI and urinary tracks
causes dilation of the pupil of the eye (mydriasis)
Use:

shock
during surgery




hypotensive states to increase blood pressure and maintain
circulation
decongestion of nasal sinuses
dilatation of pupils
ocular decongestants
appetite suppressant (those that are able to pass the blood-brain
barrier)
Side Effects:

increase blood pressure
increase heart rate
bronchodilation

Caution:
Drug Names:

most side effects are due to excessive vasoconstriction of blood
vessels which results in:
- hypertension
- hypertensive crisis
- heart palpitations
- hemorrhage (usually cerebral)
- cardiac arrhythmias
irritation of nasal sinuses (when used as decongestant due to
excessive dryness from the vasoconstrictive decrease in blood flow)
***infiltration into the tissues when these drugs are given
IV causes intense vasoconstriction of the blood vessels of
the skin which can lead to death of skin cells and
gangrene!***
Name
Epinephrine (Adrenalin)
ephedrine
metaraminol (Aramine)
methoxamine (Vasoxyl)
norepinephrine (Levophed)
phenylephrine (Neo-Synephrine)
pseudoephedrine (many OTC)
Use
vasopressor,
bronchodilator
nasal decongestant,
bronchodilator
acute allergic
reactions,
anaphylaxis—not used
in asthma patients
increase BP
increase BP
nasal decongestant
a catecholamine, also
acts on beta receptors,
extravasation if it
infiltrates
in OTC preparations,
not for pts with HTN
nasal decongestant
(Afrin)
increase BP, increases
coronary output, improves
coronary blood flow
Alpha-Adrenergics
Sympatomimetics
tetrahydrozoline (Visine)
tetrahydrozoline (Tyzine)
ophthalmic decongestant
nasal decongestant
Epinephrine (Adrenalin)
also classified as a beta adrenergic drug
Action:



increases blood pressure (alpha effect on blood vessesl))
increases heart rate (beta-1 effect on heart)
relaxes bronchial tubes (beta-2 effect on bronchus)
Use:


acute allergic reactions (anaphylaxis)
should not be used in asthma patients
Note: blocking sympathetic activity increases parasympathetic activity and vice versa.