COMSAE PHASE 1 FORM 114 Actual EXAM – 200+
QUESTIONS AND ANSWERS | VERIFIED AND WELL
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Question 1 – Microbiology / Pharmacology
A 68-year-old woman with COPD is hospitalized with fever, productive cough,
and right lower lobe infiltrate. Gram stain shows lancet-shaped gram-positive
diplococci. She has a history of anaphylaxis after amoxicillin. Which antibiotic is
contraindicated?
A) Levofloxacin
B) Vancomycin
C) Cefazolin
D) Doxycycline
E) Azithromycin
Answer: C – Cefazolin
Full Rationale:
• Option C (Cefazolin) is correct. Cefazolin is a first-generation
cephalosporin. Cephalosporins share a beta-lactam ring with penicillins;
cross-reactivity in patients with IgE-mediated penicillin allergy
(anaphylaxis) is about 1–10%. Therefore, cephalosporins are generally
contraindicated unless allergy testing confirms safety.
• Option A (Levofloxacin) – A fluoroquinolone. No cross-reactivity; safe
alternative for community-acquired pneumonia (CAP) in penicillin-allergic
patients.
• Option B (Vancomycin) – A glycopeptide. No beta-lactam; safe but usually
reserved for MRSA or severe infections.
, • Option D (Doxycycline) – A tetracycline. No cross-reactivity; can be used
for CAP.
• Option E (Azithromycin) – A macrolide. No cross-reactivity; often used in
CAP.
Key takeaway: True anaphylaxis to penicillins is a contraindication to
cephalosporins due to potential cross-reactivity.
Question 2 – Pathology / Immunology
A 4-month-old infant presents with rash, fever, failure to thrive, hypocalcemia, and
absent thymic shadow on chest X-ray. Which immunodeficiency is most likely?
A) Common variable immunodeficiency (CVID)
B) X-linked agammaglobulinemia
C) DiGeorge syndrome
D) Wiskott-Aldrich syndrome
E) Chronic granulomatous disease
Answer: C – DiGeorge syndrome
Full Rationale:
• Option C (DiGeorge syndrome) is correct. Caused by 22q11.2 deletion,
leading to thymic aplasia (absent thymic shadow), T-cell deficiency,
hypoparathyroidism (hypocalcemia), and characteristic facies.
• Option A (CVID) – Presents later in life with recurrent sinopulmonary
infections and low IgG; thymus is normal.
• Option B (X-linked agammaglobulinemia) – B-cell deficiency, no T-cell
defect; thymus normal.
• Option D (Wiskott-Aldrich syndrome) – X-linked, eczema,
thrombocytopenia (small platelets), recurrent infections; thymus present.
• Option E (Chronic granulomatous disease) – Phagocyte defect, recurrent
catalase-positive infections; thymus normal.
,Key takeaway: Thymic aplasia + hypocalcemia + T-cell deficiency = DiGeorge
syndrome.
Question 3 – Pharmacology / Neurology
A 60-year-old woman with Parkinson’s disease on carbidopa/levodopa develops
involuntary choreiform movements of the face and limbs when the medication
peaks. When she misses a dose, the movements stop. What is the best term?
A) On-off phenomenon
B) Dyskinesia
C) Akathisia
D) Tardive dyskinesia
E) Dystonia
Answer: B – Dyskinesia
Full Rationale:
• Option B (Dyskinesia) is correct. Levodopa-induced dyskinesia is a
hyperkinetic movement disorder (chorea, athetosis) that occurs at peak dose.
It resolves when the drug is reduced or stopped.
• Option A (On-off phenomenon) – Fluctuations between mobility (“on”)
and immobility (“off”) unrelated to timing of dose.
• Option C (Akathisia) – Subjective feeling of restlessness with urge to
move; not typical of levodopa.
• Option D (Tardive dyskinesia) – Caused by chronic antipsychotic use;
orofacial movements persist after drug withdrawal.
• Option E (Dystonia) – Sustained muscle contractions; can be “off” period
phenomenon in Parkinson’s.
Key takeaway: Peak-dose choreiform movements that resolve with dose reduction
= levodopa-induced dyskinesia.
, Question 4 – Cardiology / Physiology
A 55-year-old man has a mean arterial pressure (MAP) of 115 mm Hg and a
cardiac output of 5.0 L/min. Which finding indicates elevated total peripheral
resistance (TPR)?
A) Decreased heart rate
B) Elevated stroke volume
C) Narrowed pulse pressure
D) Increased mixed venous oxygen saturation
E) Decreased systolic blood pressure
Answer: C – Narrowed pulse pressure
Full Rationale:
• Option C (Narrowed pulse pressure) is correct. Increased TPR (systemic
vasoconstriction) increases diastolic pressure more than systolic, narrowing
pulse pressure (PP = SBP – DBP). MAP = CO × TPR; given normal CO,
elevated MAP implies high TPR.
• Option A (Decreased heart rate) – Not directly caused by high TPR; may
be reflex but not diagnostic.
• Option B (Elevated stroke volume) – Would tend to widen pulse pressure,
not narrow it.
• Option D (Increased mixed venous O2) – Suggests low oxygen extraction,
not directly related to TPR.
• Option E (Decreased SBP) – High TPR typically raises SBP, not lowers it.
Key takeaway: High TPR narrows pulse pressure by raising DBP more than SBP.
Question 5 – Infectious Disease / Microbiology
A 25-year-old male presents with watery diarrhea, abdominal cramps, and nausea 8
hours after eating fried rice from a takeaway restaurant. He is afebrile. What is the
most likely pathogen?
QUESTIONS AND ANSWERS | VERIFIED AND WELL
DETAILED ANSWERS | PLUS RATIONALES |
GUARANTEED PASS | LATEST EXAM UPDATE |
STUVIA VERIFIED | EXAM PREP | STUDY GUIDE
Question 1 – Microbiology / Pharmacology
A 68-year-old woman with COPD is hospitalized with fever, productive cough,
and right lower lobe infiltrate. Gram stain shows lancet-shaped gram-positive
diplococci. She has a history of anaphylaxis after amoxicillin. Which antibiotic is
contraindicated?
A) Levofloxacin
B) Vancomycin
C) Cefazolin
D) Doxycycline
E) Azithromycin
Answer: C – Cefazolin
Full Rationale:
• Option C (Cefazolin) is correct. Cefazolin is a first-generation
cephalosporin. Cephalosporins share a beta-lactam ring with penicillins;
cross-reactivity in patients with IgE-mediated penicillin allergy
(anaphylaxis) is about 1–10%. Therefore, cephalosporins are generally
contraindicated unless allergy testing confirms safety.
• Option A (Levofloxacin) – A fluoroquinolone. No cross-reactivity; safe
alternative for community-acquired pneumonia (CAP) in penicillin-allergic
patients.
• Option B (Vancomycin) – A glycopeptide. No beta-lactam; safe but usually
reserved for MRSA or severe infections.
, • Option D (Doxycycline) – A tetracycline. No cross-reactivity; can be used
for CAP.
• Option E (Azithromycin) – A macrolide. No cross-reactivity; often used in
CAP.
Key takeaway: True anaphylaxis to penicillins is a contraindication to
cephalosporins due to potential cross-reactivity.
Question 2 – Pathology / Immunology
A 4-month-old infant presents with rash, fever, failure to thrive, hypocalcemia, and
absent thymic shadow on chest X-ray. Which immunodeficiency is most likely?
A) Common variable immunodeficiency (CVID)
B) X-linked agammaglobulinemia
C) DiGeorge syndrome
D) Wiskott-Aldrich syndrome
E) Chronic granulomatous disease
Answer: C – DiGeorge syndrome
Full Rationale:
• Option C (DiGeorge syndrome) is correct. Caused by 22q11.2 deletion,
leading to thymic aplasia (absent thymic shadow), T-cell deficiency,
hypoparathyroidism (hypocalcemia), and characteristic facies.
• Option A (CVID) – Presents later in life with recurrent sinopulmonary
infections and low IgG; thymus is normal.
• Option B (X-linked agammaglobulinemia) – B-cell deficiency, no T-cell
defect; thymus normal.
• Option D (Wiskott-Aldrich syndrome) – X-linked, eczema,
thrombocytopenia (small platelets), recurrent infections; thymus present.
• Option E (Chronic granulomatous disease) – Phagocyte defect, recurrent
catalase-positive infections; thymus normal.
,Key takeaway: Thymic aplasia + hypocalcemia + T-cell deficiency = DiGeorge
syndrome.
Question 3 – Pharmacology / Neurology
A 60-year-old woman with Parkinson’s disease on carbidopa/levodopa develops
involuntary choreiform movements of the face and limbs when the medication
peaks. When she misses a dose, the movements stop. What is the best term?
A) On-off phenomenon
B) Dyskinesia
C) Akathisia
D) Tardive dyskinesia
E) Dystonia
Answer: B – Dyskinesia
Full Rationale:
• Option B (Dyskinesia) is correct. Levodopa-induced dyskinesia is a
hyperkinetic movement disorder (chorea, athetosis) that occurs at peak dose.
It resolves when the drug is reduced or stopped.
• Option A (On-off phenomenon) – Fluctuations between mobility (“on”)
and immobility (“off”) unrelated to timing of dose.
• Option C (Akathisia) – Subjective feeling of restlessness with urge to
move; not typical of levodopa.
• Option D (Tardive dyskinesia) – Caused by chronic antipsychotic use;
orofacial movements persist after drug withdrawal.
• Option E (Dystonia) – Sustained muscle contractions; can be “off” period
phenomenon in Parkinson’s.
Key takeaway: Peak-dose choreiform movements that resolve with dose reduction
= levodopa-induced dyskinesia.
, Question 4 – Cardiology / Physiology
A 55-year-old man has a mean arterial pressure (MAP) of 115 mm Hg and a
cardiac output of 5.0 L/min. Which finding indicates elevated total peripheral
resistance (TPR)?
A) Decreased heart rate
B) Elevated stroke volume
C) Narrowed pulse pressure
D) Increased mixed venous oxygen saturation
E) Decreased systolic blood pressure
Answer: C – Narrowed pulse pressure
Full Rationale:
• Option C (Narrowed pulse pressure) is correct. Increased TPR (systemic
vasoconstriction) increases diastolic pressure more than systolic, narrowing
pulse pressure (PP = SBP – DBP). MAP = CO × TPR; given normal CO,
elevated MAP implies high TPR.
• Option A (Decreased heart rate) – Not directly caused by high TPR; may
be reflex but not diagnostic.
• Option B (Elevated stroke volume) – Would tend to widen pulse pressure,
not narrow it.
• Option D (Increased mixed venous O2) – Suggests low oxygen extraction,
not directly related to TPR.
• Option E (Decreased SBP) – High TPR typically raises SBP, not lowers it.
Key takeaway: High TPR narrows pulse pressure by raising DBP more than SBP.
Question 5 – Infectious Disease / Microbiology
A 25-year-old male presents with watery diarrhea, abdominal cramps, and nausea 8
hours after eating fried rice from a takeaway restaurant. He is afebrile. What is the
most likely pathogen?
