A 12-year-old girl was diagnosed with strep throat and given penicillin, but had an anaphylactic reaction. She was given epinephrine, which will cause vasoconstriction through alpha-1 adrenoceptors in her vascular system and bronchial muscle relaxation through beta-2 adrenoceptors in her respiratory system to treat the reaction.

2. A 12-year old girl presents to your office with a sore
throat and fever. You diagnose her with pharyngitis
caused by group A beta hemolytic streptococcus.
She is given an IM injection of penicillin.
Approximately 5 minutes later , she is found to be in
respiratory distress and audibly wheezing. Her skin
is mottled and cool. She is tachycardiac, and her BP
has fallen to 70/20 mm hg. You immediately
diagnose her as having an anphylactic reaction to
the penicillin and give an IM injection of
epinephrine.

3. Questions
1. What effect will epinephrine have on this patient’s
vascular system?
2. Which adrenoceptor primarily mediates the vascular
response?
3. What effect will epinephrine have on her respiratory
system?
4. Which adrenoceptor primarily mediates the
respiratory system response?

4. Summary
 A 12-year-old girl with “strep sore throat” is
given an injection of penicillin and
developes an acute anaphylactic reaction

5. Effect of epinephrine on vascular
system
Vasoconstriction

6. Adrenoceptor which primarily
mediates the vascular response
Alpha -1

7. Effect of epinephrine on the
pulmonary system
 Bronchial muscle relaxation

8. Adrenoceptor which primarily
mediates the pulmonary response
 Beta-2