C H A P T E R 3 0
Adrenergic agonists
461
CRITICAL THINKING SCENARIO
Adrenergic agonist toxicity
THE SITUATION
M.C. is a 26-year-old man who has recently moved from
Western Australia to Tasmania. He has been suffering
from sinusitis, runny nose and cold-like symptoms for
2 weeks. He appears at an outpatient hospital with
complaints of headache, “jitters”, inability to sleep, loss
of appetite and a feeling of impending doom. He states
that he feels “on edge” and has not been productive in
his job as a watch repairman and jeweller. According to
his history, M.C. has been treated with several different
drugs for nocturnal enuresis, a persisting childhood
problem. Only ephedrine, which he has been taking
for 2 years, has been successful (an off-label use of the
drug). He has no other significant health problems. He
denies any side effects from the use of ephedrine but
does admit to self-medicating his nagging cold with OTC
preparations—a nasal spray used four times a day and
a combination decongestant–pain reliever. A physical
examination reveals a pulse of 104 beats/minute, blood
pressure 154/86 mmHg, and respiration 16/minute.
M.C. appears flushed and slightly diaphoretic.
CRITICAL THINKING
What are the important care implications for M.C.?
Think
about the problems that confront a person in a new area
seeking healthcare for the first time.
What could be causing the problems that M.C. presents
with?
The diagnosis of ephedrine overdose was eventually
made based on the person’s history of OTC drug use and the
presenting signs and symptoms.
Keeping in mind that this diagnosis means that M.C. has an
overstimulated sympathetic stress reaction, what other
physical problems can be anticipated?
Overwhelming
feelings of anxiety and stress are influencing M.C.’s response
to work and healthcare.
Given this fact, how may the health professional best
deal with explaining the problem and how it could
have happened—without making the person feel
uninformed or that the practice of his former healthcare
provider is being questioned?
What treatment should be planned and what teaching
points should be covered for M.C.?
DISCUSSION
The first step in caring for M.C. is establishing a trusting
relationship to help alleviate some of the anxiety he is
feeling. Being in a new state and seeking healthcare in a
new setting can be very stressful for people under normal
circumstances. In M.C.’s case, the sympathomimetic effects
of the drugs that he has been taking make him feel even
more anxious and jittery.
A careful history will help to determine whether
there are any underlying medical problems that could
be exacerbated by these drug effects. A review of M.C.’s
nocturnal enuresis and the treatments that have been
tried will enhance understanding of his former healthcare
and suggest possible implications for further study. This
questioning will also reassure M.C. that he is an important
member of the health team and that the information he
has to offer is valued.
A careful review of the OTC drugs that M.C. has
been using will be informative for the person, as well
as for the healthcare providers, who have not actually
checked OTC drugs for those specific ingredients, because
combining them to ease signs and symptoms often
results in toxic levels and symptoms of overdose. Many
of these preparations contain sympathomimetics, such
as phenylephrine, which will have additive effects to the
ephedrine. M.C. will need a full teaching program about
the effects of his ephedrine and which OTC drugs to avoid.
The treatment for his current problems involves withdrawal
of the OTC drugs; when these drug levels fall, the signs
and symptoms will disappear. M.C. may also wish to avoid
nicotine and caffeine because these stimulants could
increase his “jitters”.
To build trust and ensure that the underlying cause
of the problem was drug toxicity, M.C. should receive
written instructions that highlight warning signs to
report, including chest pain, palpitations and difficulty
voiding. He also should be given the healthcare provider’s
telephone number with instructions to call the next day
and report on his health status. Finally, specimens of nasal
discharge should be cultured and antibiotic treatment
prescribed, if appropriate.
CARE GUIDE FOR M.C.: ADRENERGIC AGONIST
TOXICITY
Assessment: History and examination
Assess the person’s history of drug allergies, cardiovascular
dysfunction, pheochromocytoma, narrow-angle
glaucoma, prostatic hypertrophy, thyroid disease or
diabetes, as well as concurrent use of MAO inhibitors,
tricyclic antidepressants, reserpine, ephedrine or urinary
alkalinisers.
Focus the physical examination on the following:
CV: Blood pressure, pulse rate, peripheral perfusion and
ECG
CNS: orientation, affect, reflexes, peripheral sensation and
vision
