Usmle Club Session No. 3
December 5, 2013


A 20-year-old woman presents to the Emergency
Department after being dumped in the ambulance
bay with a note that said only that “she was doing
Ecstasy at a party when she became unconscious.”
This patient currently remains unconscious, with a heart
rate of 140 bpm, temperature of 103.5°F, pinpoint
pupils, absent bowel sounds, blood pressure of 85/40
mm Hg, profuse sweating, and oxygen saturation of
86 percent on room air. Which of the following would
not be a clinical manifestation of an Ecstasy patient?
A. Tachycardia.
B. Hyperthermia.
C. Pinpoint pupils.
D. Diaphoresis.
E. Respiratory depression.
1

A 20-year-old woman presents to the Emergency
Department after being dumped in the ambulance
bay with a note that said only that “she was doing
Ecstasy at a party when she became unconscious.”
This patient currently remains unconscious, with a heart
rate of 140 bpm, temperature of 103.5°F, pinpoint
pupils, absent bowel sounds, blood pressure of 85/40
mm Hg, profuse sweating, and oxygen saturation of
86 percent on room air. Which of the following would
not be a clinical manifestation of an Ecstasy patient?
A. Tachycardia.
B. Hyperthermia.
C. Pinpoint pupils.
D. Diaphoresis.
E. Respiratory depression.
1
Correct answer = C. Tachycardia, hyperthermia, diaphoresis, and unconsciousness are typical signs
and
symptoms of ecstasy overdose. Pinpoint pupils as
well as absent bowel sounds, low oxygen saturation
(respiratory depression), and hypotension are good
indicators of opioid overdose. This is likely a multidrug
overdose.

A 41-year-old male pocketwatch maker reports
to the Emergency Department after he was found
unconscious on the floor of the shop by a coworker.
The coworker states that the patient complained of
being cold this morning around 8 a.m. (the central
heat was broken, and the outdoor temperature was
34°F) and that since noon, he had been complaining
of headache, drowsiness, confusion, and nausea.
The clinician notices that he has cherry red lips and
nail beds. What is the most likely toxin causing his
signs and symptoms?
A. Asbestos.
B. Cyanide.
C. Chloroform.
D. Carbon monoxide.
E. Ecstasy.
2

A 41-year-old male pocketwatch maker reports
to the Emergency Department after he was found
unconscious on the floor of the shop by a coworker.
The coworker states that the patient complained of
being cold this morning around 8 a.m. (the central
heat was broken, and the outdoor temperature was
34°F) and that since noon, he had been complaining
of headache, drowsiness, confusion, and nausea.
The clinician notices that he has cherry red lips and
nail beds. What is the most likely toxin causing his
signs and symptoms?
A. Asbestos.
B. Cyanide.
C. Chloroform.
D. Carbon monoxide.
E. Ecstasy.
2
Correct answer = D. Although watch makers and
other professionals who use electroplating may be
at higher risk for cyanide exposure because many
plating baths use cyanide-containing ingredients,
this patient shows classic signs of carbon monoxide poisoning, such as cherry red lips and nail
beds, headache, confusion, nausea, and drowsiness leading to unconsciousness.
The history also leads us to believe that this person
may have been using a stove or space heater
to stay warm. Asbestos poisoning commonly first
presents as lung cancer or mesothelioma. Cyanide in
low doses can present with loss of consciousness, headache, and confusion and there is typically
giddiness in the early stages, breathing with difficulty, and pink skin (not just lips and nails),
and then later rapidly progresses to deep coma and death. Chloroform can cause dizziness, fatigue,
and unconsciousness, but these patients do not present with cherry red lips and nails. These
symptoms are not consistent with Ecstasy overdose, in which hyperthermia, not “feeling cold” is
typically seen.

An elderly diabetic patient is admitted to the hospital
with pneumonia. The sputum culture stains for a
gram-negative rod. The patient is started on IV ampicillin.
Two days later, the patient is not improving,
and the microbiology laboratory reports the organism
to be a b-lactamase producing H. influenzae.
What course of treatment is indicated?
A. Continue with the IV ampicillin.
B. Switch to IV cefotaxime.
C. Switch to oral vancomycin.
D. Add gentamicin to the ampicillin therapy.
3

An elderly diabetic patient is admitted to the hospital
with pneumonia. The sputum culture stains for a
gram-negative rod. The patient is started on IV ampicillin.
Two days later, the patient is not improving,
and the microbiology laboratory reports the organism
to be a b-lactamase producing H. influenzae.
What course of treatment is indicated?
A. Continue with the IV ampicillin.
B. Switch to IV cefotaxime.
C. Switch to oral vancomycin.
D. Add gentamicin to the ampicillin therapy.
3
Correct answer = B. Cefotaxime, a third-generation
cephalosporin, is not susceptible to hydrolysis by
b-lactamase, is bactericidal, and has few adverse
effects. To continue the ampicillin is not appropriate,
because the organism is resistant to it. Vancomycin
is used in the treatment of serious infections caused
by b-lactamase resistant, gram-positive microorganisms
(H. influenzae is gram-negative). Although gentamicin has some activity against H. influenzae, it
also causes adverse effects, such as nephrotoxicity, which may harm the patient.

A patient with degenerative joint disease is to undergo
insertion of a hip prosthesis. To avoid complications
due to postoperative infection, the surgeon
will pretreat this patient with an antibiotic. This hospital
has a significant problem with MRSA. Which of
the following antibiotics should the surgeon select?
A. Ampicillin.
B. Imipenem/cilastatin.
C. Gentamicin/piperacillin.
D. Vancomycin.
E. Cefazolin.
4

A patient with degenerative joint disease is to undergo
insertion of a hip prosthesis. To avoid complications
due to postoperative infection, the surgeon
will pretreat this patient with an antibiotic. This hospital
has a significant problem with MRSA. Which of
the following antibiotics should the surgeon select?
A. Ampicillin.
B. Imipenem/cilastatin.
C. Gentamicin/piperacillin.
D. Vancomycin.
E. Cefazolin.
4
Correct answer = D. The only antibiotic on the list
that is effective against MRSA is vancomycin.

A 45-year-old male who received a renal transplant
3 months previously and is being maintained on prednisone, cyclosporine, and mycophenolate mofetil
is found to have increased creatinine levels, and a kidney
biopsy indicating severe rejetion. Which of the
following courses of therapy would be appropriate?
A. Increased dose of prednisone.
B. Hemodialysis.
C. Treatment with rabbit antithymocyte globulin.
D. Treatment with sirolimus.
E. Treatment with azathioprine.
5

A 45-year-old male who received a renal transplant
3 months previously and is being maintained on prednisone, cyclosporine, and mycophenolate mofetil
is found to have increased creatinine levels, and a kidney
biopsy indicating severe rejetion. Which of the
following courses of therapy would be appropriate?
A. Increased dose of prednisone.
B. Hemodialysis.
C. Treatment with rabbit antithymocyte globulin.
D. Treatment with sirolimus.
E. Treatment with azathioprine.
5
Correct answer = C. This patient is apparently undergoing
an acute rejection of the kidney. The most
effective treatment would be administration of an
antibody. Increasing the dose of prednisone may
have some effect, but would not be enough to treat
the rejection. Sirolimus is used prophylactically with
cyclosporine to prevent renal rejection but is less
effective when an episode is occurring. Furthermore,
the combination of cyclosporine and sirolimus is
more nephrotoxic than cyclosporine alone. Azathioprine
has no benefit over mycophenolate.

A 9-year-old girl has severe asthma, which required
three hospitalizations in the last year. She is now
receiving therapy that has greatly reduced the frequency
of these severe attacks. Which of the following
therapies is most likely responsible for this
benefit?
A. Albuterol by aerosol.
B. Ipratropium by inhaler.
C. Fluticasone by aerosol.
D. Theophylline orally.
E. Zafirlukast orally.
6

A 9-year-old girl has severe asthma, which required
three hospitalizations in the last year. She is now
receiving therapy that has greatly reduced the frequency
of these severe attacks. Which of the following
therapies is most likely responsible for this
benefit?
A. Albuterol by aerosol.
B. Ipratropium by inhaler.
C. Fluticasone by aerosol.
D. Theophylline orally.
E. Zafirlukast orally.
6
Correct answer = C. Administration of a corticosteroid
directly to the lung significantly reduces the frequency
of severe asthma attacks. This benefit is accomplished
with minimal risk of the severe systemic adverse effects of corticosteroid therapy. Albuterol is
only used to treat acute asthmatic episodes. The other agents may reduce the severity of attacks
but not to the same degree or consistency as fluticasone (or other corticosteroids).

A couple celebrating their fortieth wedding anniversary
is given a trip to Peru to visit Machu Picchu. Due
to past experiences while traveling, they ask their
doctor to prescribe an agent for diarrhea. Which of
the following would be effective?
A. Omeprazole.
B. Loperamide.
C. Famotidine.
D. Lorazepam.
7

A couple celebrating their fortieth wedding anniversary
is given a trip to Peru to visit Machu Picchu. Due
to past experiences while traveling, they ask their
doctor to prescribe an agent for diarrhea. Which of
the following would be effective?
A. Omeprazole.
B. Loperamide.
C. Famotidine.
D. Lorazepam.
7
Correct answer = B. Loperamide is the only drug in
this set that has antidiarrheal activity. Omeprazole
is a proton-pump inhibitor, famotidine antagonizes
the H2 receptor, and lorazepam is a benzodiazepine
that is a sedative and anxiolytic agent.

A 57-year-old man complains of fever, headache,
confusion, aversion to light, and neck rigidity. A presumptive diagnosis of bacterial meningitis is
made.
Antimicrobial therapy should be initiated after which
one of the following occurrences?
A. Fever is reduced with antipyretic drugs.
B. Sample of blood and cerebrospinal fluid have
     been taken.
C. A Gram stain has been performed.
D. The results of antibacterial drug susceptibility
     tests are available.
E. Infecting organism(s) have been identified by the
     microbiology laboratory.
8

A 57-year-old man complains of fever, headache,
confusion, aversion to light, and neck rigidity. A presumptive diagnosis of bacterial meningitis is
made.
Antimicrobial therapy should be initiated after which
one of the following occurrences?
A. Fever is reduced with antipyretic drugs.
B. Sample of blood and cerebrospinal fluid have
     been taken.
C. A Gram stain has been performed.
D. The results of antibacterial drug susceptibility
     tests are available.
E. Infecting organism(s) have been identified by the
    microbiology laboratory.
8
Correct answer = B. Bacterial meningitis is a medical
emergency that requires immediate diagnosis and
treatment. Specimens for possible microbial identification
must be obtained before drugs are administered.
Therapy should not be delayed until laboratory results are available.

A 31-year-old white intravenous drug user was admitted
to the hospital with a 4-week history of cough
and fever. A chest radiograph showed left upper
lobe cavitary infiltrate. Cultures of sputum yielded
M. tuberculosis susceptible to all antimycobacterial
drugs. The patient received isoniazid, rifampin, and
pyrazinamide. The patient’s sputum remained culture-
positive for the subsequent 4 months. Which one of the following is the most likely cause of
treatment
failure?
A. False-positive cultures.
B. Maladsorption of the medications.
C. Concomitant infection with HIV.
D. Noncompliance by the
9

A 31-year-old white intravenous drug user was admitted
to the hospital with a 4-week history of cough
and fever. A chest radiograph showed left upper
lobe cavitary infiltrate. Cultures of sputum yielded
M. tuberculosis susceptible to all antimycobacterial
drugs. The patient received isoniazid, rifampin, and
pyrazinamide. The patient’s sputum remained culture-
positive for the subsequent 4 months. Which
one of the following is the most likely cause of treatment
failure?
A. False-positive cultures.
B. Maladsorption of the medications.
C. Concomitant infection with HIV.
D. Noncompliance by the patient.
9
Correct answer = D. Although malabsorption of the
drugs and the emergence of drug resistance are
possibilities, the most common cause of treatment
failure is patient‘s nonadherence to the treatment protocol.
Better treatment completion rates occur with “directly
observed therapy.” False-positive cultures is a
possible but unlikely explanation.

A soldier’s unit has come under attack with a nerve
agent. The symptoms exhibited are skeletal muscle
paralysis, profuse bronchial secretions, miosis, bradycardia, and convulsions. The alarm indicates
exposure to an organophosphate.
What is the correct treatment?
A. Do nothing until you can confirm the nature of
     the nerve agent.
B. Administer atropine, and attempt to confirm the
     nature of the nerve agent.
C. Administer atropine and 2-PAM (pralidoxime).
D. Administer pralidoxime.
10

A soldier’s unit has come under attack with a nerve
agent. The symptoms exhibited are skeletal muscle
paralysis, profuse bronchial secretions, miosis, bradycardia, and convulsions. The alarm indicates
exposure to an organophosphate. What is the correct
treatment?
A. Do nothing until you can confirm the nature of
    the nerve agent.
B. Administer atropine, and attempt to confirm the
    nature of the nerve agent.
C. Administer atropine and 2-PAM (pralidoxime).
D. Administer pralidoxime.
10
Correct answer = C. Organophosphates exert their
effect by irreversibly binding to acetylcholinesterase
(AChE) and, thus, can cause a cholinergic crisis.
Administration of atropine will block the muscarinic
sites, but it will not reactivate the enzyme, which will
remain blocked for a long period of time. Therefore,
it is essential to also administer pralidoxime as soon
as possible to reactivate the enzyme before aging
occurs. Administering pralidoxime alone will not
protect the patient against the effects of acetylcholine
resulting from AChE inhibition.

A 50-year-old male farm worker is brought to the
emergency room. He was found confused in the orchard
and since then has lost consciousness. His heart
rate is 45, and his blood pressure is 80/40 mm Hg. He
is sweating and salivating profusely. Which of the following treatments is indicated?
A. Physostigmine.
B. Norepinephrine.
C. Trimethaphan.
D. Atropine.
E. Edrophonium.
11

A 50-year-old male farm worker is brought to the
emergency room. He was found confused in the orchard
and since then has lost consciousness. His heart
rate is 45, and his blood pressure is 80/40 mm Hg. He
is sweating and salivating profusely. Which of the following treatments is indicated?
A. Physostigmine.
B. Norepinephrine.
C. Trimethaphan.
D. Atropine.
E. Edrophonium.
11
Correct answer = D. The patient is exhibiting signs
of cholinergic stimulation. Because he is a farmer, insecticide poisoning is a likely diagnosis.
Thus, either
intravenous or intramuscular doses of atropine are
indicated to antagonize the muscarinic symptoms.
Physostigmine and edrophonium are cholinesterase
inhibitors and would exacerbate the problem. Norepinephrine would not be effective in combating
the cholinergic stimulation. Trimethaphan, being a
ganglionic blocker, would also worsen the condition.

A patient with a gunshot wound to the abdomen,
which has resulted in spillage of intestinal contents,
is brought to the emergency room. Which antibiotic
would you select to effectively treat an infection due
to Bacteroides fragilis?
A. Aztreonam.
B. Clindamycin.
C. Gentamicin.
D. Azithromycin.
E. Doxycycline.
12

A patient with a gunshot wound to the abdomen,
which has resulted in spillage of intestinal contents,
is brought to the emergency room. Which antibiotic
would you select to effectively treat an infection due
to Bacteroides fragilis?
A. Aztreonam.
B. Clindamycin.
C. Gentamicin.
D. Azithromycin.
E. Doxycycline.
12
Correct answer = B. Bacteroides fragilis is an anaerobic organism. The only drug on the list that
is effective against it is clindamycin. Aztreonam is effective against aerobic,
not anaerobic organisms. Gentamicin works against
Francisella tularensis, a gram-negative organism
rarely causing infection, and in combination with
penicillin G against Enterococci. Azithromycin is
used for respiratory infections. The only anaerobic
organisms that tetracyclines (doxyxycline) are
effective against are Clostridium perfringens and
Clostridium tetani.

A very agitated young male was brought to the
emergency room by the police. Psychiatric examination
revealed that he had snorted cocaine several
times in the past few days, the last time being 10
hours previously. He was given a drug that sedated
him, and he fell asleep. The drug that was used to
counter this patient’s apparent cocaine withdrawal
was very likely:
A. Phenobarbital.
B. Lorazepam.
C. Cocaine.
D. Hydroxyzine.
E. Fluoxetine.
A very agitated young male was brought to the
emergency room by the police. Psychiatric examination
revealed that he had snorted cocaine several
times in the past few days, the last time being 10
hours previously. He was given a drug that sedated
him, and he fell asleep. The drug that was used to
counter this patient’s apparent cocaine withdrawal
was very likely:
A. Phenobarbital.
B. Lorazepam.
C. Cocaine.
D. Hydroxyzine.
E. .
13

A very agitated young male was brought to the
emergency room by the police. Psychiatric examination
revealed that he had snorted cocaine several
times in the past few days, the last time being 10
hours previously. He was given a drug that sedated
him, and he fell asleep. The drug that was used to
counter this patient’s apparent cocaine withdrawal
was very likely:
A. Phenobarbital.
B. Lorazepam.
C. Cocaine.
D. Hydroxyzine.
E. Fluoxetine.
A very agitated young male was brought to the
emergency room by the police. Psychiatric examination
revealed that he had snorted cocaine several
times in the past few days, the last time being 10
hours previously. He was given a drug that sedated
him, and he fell asleep. The drug that was used to
counter this patient’s apparent cocaine withdrawal
was very likely:
A. Phenobarbital.
B. Lorazepam.
C. Cocaine.
D. Hydroxyzine.
E. Fluoxetine.
13
Correct answer = B. The anxiolytic properties of
benzodiazepines, such as lorazepam, make them the
drugs of choice in treating the anxiety and agitation
of cocaine withdrawal. Lorazepam also has hypnotic
properties. Phenobarbital has hypnotic properties,
but its anxiolytic properties are inferior to those of
the benzodiazepines. Cocaine itself could counteract
the agitation of withdrawal, but its use would not be proper therapy. Hydroxyzine, an
antihistamine, is effective as a hypnotic, and it is sometimes used to deal with anxiety,
especially if emesis is a problem. Fluoxetine is an antidepressant with no immediate effects on
anxiety.

A 58-year-old male has been effectively treated for
Paget disease for approximately 6 months. He is now
beginning to experience renewed bone pain and
radiologic evidence of advancing disease. Which of
the following drugs is most likely to have resulted in
this failure of therapy?
A. Alendronate.
B. Calcitonin.
C. Dihydrotachysterol.
D. Ergocalciferol.
E. Raloxifene.
14

A 58-year-old male has been effectively treated for
Paget disease for approximately 6 months. He is now
beginning to experience renewed bone pain and
radiologic evidence of advancing disease. Which of
the following drugs is most likely to have resulted in
this failure of therapy?
A. Alendronate.
B. Calcitonin.
C. Dihydrotachysterol.
D. Ergocalciferol.
E. Raloxifene.
14
Correct answer = B. Paget disease can be treated effectively with either a bisphosphonate or
calcitonin.
Calcitonin therapy is complicated by the fact that
tolerance develops to the action of the hormone
when administration is continuous over a long period
of time. The other drugs are not effective in the
treatment of Paget disease.

Patient presents with salivation, lacrimation, urination
and defecation as side effects of a medication. Which
one of the following receptors mediates the actions
of this drug?
A. Nicotinic receptors.
B. a Receptors.
C. Muscarinic receptors.
D. b Receptors.
15

Patient presents with salivation, lacrimation, urination
and defecation as side effects of a medication. Which
one of the following receptors mediates the actions
of this drug?
A. Nicotinic receptors.
B. a Receptors.
C. Muscarinic receptors.
D. b Receptors.
15
Correct answer = C. The muscarinic receptors of
the parasympathetic nervous system maintain essential
body functions such as digestion and waste
elimination. The nicotinic receptors are a receptor
for acetylcholine. It plays a major role in skeletal
muscles, ganglia and synthesis of catecholamines in
the adrenal medulla. a and b receptors are receptors
for norepinephrine and epinephrine and activation
of these receptors does not produce these effects.

•Clark-Lippincott's, Illustrated Reviews – Pharmacology, 5th, 2012
•www.wikipedia.com