(e) Gastrointestinal (G.I.) tract. Epinephrine decreases the motility and
tone of the gastrointestinal tract (alpha2 and beta2 effects).
(f) Central nervous system (CNS). Epinephrine provides some
stimulation; therefore, it may produce some restlessness, apprehension, headache, and
Indications for the use of epinephrine.
(a) Relieve bronchospasm. Epinephrine is used to relieve
bronchiospasm as is seen with patients who have asthma. It opens the breathing
pathways and allows for easier breathing.
(b) Prolong the action of local anesthetics. Epinephrine is sometimes
combined with a local anesthetic (that is, lidocaine). Because epinephrine is a
vasoconstrictor, it prolongs the effects of the local anesthetic by increasing the time the
local anesthetic is in contact with the affected tissue (reduces blood flow to and from the
(c) Restore cardiac rhythm in cardiac arrest. Because of its effects
upon the heart, epinephrine is administered to increase cardiac output and rate in
persons who experience cardiac arrest.
(d) Stop bleeding on topical surfaces. Because it is a vasoconstrictor,
epinephrine is sometimes applied to topical surfaces to reduce or stop bleeding.
(e) Treat allergic reactions. Epinephrine is the drug of choice for the
treatment of anaphylactic shock. It overcomes the physiological effects of histamine
(substance which causes the anaphylactoid reaction). It should be noted that
epinephrine is not an antihistamine. One, epinephrine reverses the drop in blood
pressure caused by the vasodilatation effect of histamine because epinephrine
produces vasoconstriction. Two, the epinephrine reverses the bronchoconstriction
produced by the anaphylaxis.
Cautions and warnings associated with the use of epinephrine.
(a) Epinephrine can cause anxiety, tenseness, headache, and an
awareness of a forceful, rapid heart beat.
(b) Epinephrine should be used cautiously in-patients who have
hypertension (high blood pressure), hyperthyroidism, and heart disease (that is,