1
COMSAE PHASE 1 FORM 114 Actual EXAM – 176
QUESTIONS AND ANSWERS | VERIFIED AND WELL
DETAILED ANSWERS | PLUS RATIONALES |
GUARANTEED PASS | LATEST EXAM UPDATE | STUVIA
VERIFIED | EXAM PREP | STUDY GUIDE | PRACTICE TEST
Question 1 – Microbiology / Pharmacology
A 68-year-old woman with chronic obstructive pulmonary disease (COPD) is hospitalized with
fever, productive cough, and a chest X-ray showing a right lower lobe infiltrate. Gram stain
reveals numerous neutrophils and lancet-shaped gram-positive diplococci. She has a history
of anaphylaxis after taking amoxicillin 10 years ago. Which antibiotic is contraindicated in this
patient?
A) Levofloxacin
B) Vancomycin
C) Cefazolin
D) Doxycycline
E) Azithromycin
:Answer: C – Cefazolin
Full Rationale:
• Option C (Cefazolin) is correct because cefazolin is a first-generation cephalosporin.
Cephalosporins share a beta-lactam ring structure with penicillins, and cross-reactivity
occurs in approximately 1–10% of penicillin-allergic patients. Given her history of
anaphylaxis (a severe, IgE-mediated reaction) to amoxicillin, cephalosporins should be
avoided unless skin testing confirms no allergy, and they are contraindicated in this
scenario.
• Option A (Levofloxacin) – A fluoroquinolone. It is not contraindicated based on
penicillin allergy; it is a safe alternative for CAP in penicillin-allergic patients. However, it
carries risks of tendonitis, QT prolongation, and C. difficile. Not the correct answer
because it is not contraindicated.
• Option B (Vancomycin) – A glycopeptide effective against gram-positive cocci
including Streptococcus pneumoniae. It has no cross-reactivity with penicillins. It can be
pg. 1
,2
used, though usually reserved for MRSA or severe penicillin-resistant pneumococcus.
Not contraindicated.
• Option D (Doxycycline) – A tetracycline antibiotic. No beta-lactam ring, so safe in
penicillin allergy. May be used for respiratory infections. Not contraindicated.
• Option E (Azithromycin) – A macrolide. Also safe in penicillin allergy, commonly used for
CAP. No cross-reactivity. Not contraindicated.
Key takeaway: A true penicillin allergy with anaphylaxis contraindicates the use of
cephalosporins due to potential cross-reactivity.
Question 2 – Pathology / Immunology
A 4-month-old infant is brought to the emergency department with severe diarrhea, oral
thrush, and failure to thrive. Laboratory findings show lymphopenia with absent T cells but
normal B cell counts. A chest X-ray reveals absence of a thymic shadow. Which
immunodeficiency disorder 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. DiGeorge syndrome (22q11.2 deletion) results
from abnormal development of the 3rd and 4th pharyngeal pouches, leading to thymic
aplasia (absent T cells), hypocalcemia (parathyroid hypoplasia), and cardiac anomalies.
The presentation of T-cell deficiency (oral thrush, failure to thrive, severe diarrhea),
absent thymic shadow, and lymphopenia with absent T cells is classic.
• Option A (CVID) – Presents later in life (adolescence or adulthood) with recurrent
sinopulmonary infections and autoimmune disease. Not associated with absent thymic
shadow or presentation at 4 months.
• Option B (X-linked agammaglobulinemia) – Bruton’s disease; blocks B cell maturation,
leading to absent B cells and very low immunoglobulins after maternal antibodies wane
(around 6 months). T cells are normal. Not fitting the absent T cells and thymic shadow.
pg. 2
,3
• Option D (Wiskott-Aldrich syndrome) – Characterized by the triad of eczema,
thrombocytopenia (small platelets), and recurrent infections. T cells may be affected but
not absent at birth; thymic shadow is present.
• Option E (Chronic granulomatous disease) – A defect in the NADPH oxidase pathway,
leading to inability of phagocytes to kill catalase-positive organisms. Not associated with
lymphopenia or absent thymus; presents with recurrent abscesses and granulomas.
Key takeaway: Thymic aplasia + absent T cells + hypocalcemia = DiGeorge syndrome.
Question 3 – Pharmacology / Neurology
A 60-year-old woman with Parkinson’s disease has been taking carbidopa-levodopa for 4
years. She develops distressing involuntary movements of the face and neck that subside
when the medication is withheld. Which term best describes this phenomenon?
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 dyskinesias are involuntary,
choreiform movements that occur as a peak-dose side effect. They are directly related
to dopamine receptor stimulation and improve when levodopa is reduced or withheld.
They are different from tardive dyskinesia which is caused by long-term antipsychotic
use.
• Option A (On-off phenomenon) – Fluctuations in motor response where the patient
cycles between “on” periods (good mobility) and “off” periods (hypomobile, stiff). Not a
description of involuntary movements per se, but rather the variability of therapeutic
effect.
• Option C (Akathisia) – A subjective sense of inner restlessness and an urge to move,
often seen with antipsychotic medications. Not facial/neck choreiform movements.
• Option D (Tardive dyskinesia) – Involuntary movements, often of the face (tongue
rolling, lip smacking), caused by chronic blockade of dopamine receptors (e.g., by
antipsychotics). It is not relieved by withholding levodopa; it is exacerbated by
dopamine antagonists.
pg. 3
, 4
• Option E (Dystonia) – Sustained or intermittent muscle contractions causing abnormal
postures or repetitive movements. Can be a complication of long-term levodopa
therapy, but usually occurs as an “off” period phenomenon (early morning dystonia).
The description of face/neck movements that subside when the drug is withheld points
to peak-dose dyskinesia.
Key takeaway: Levodopa-induced dyskinesias are hyperkinetic movements that appear at peak
drug levels and resolve when the dose is lowered or the drug is stopped.
Question 4 – Cardiology / Physiology
A 55-year-old man has a mean arterial pressure (MAP) of 95 mm Hg, a heart rate of 80 bpm,
and a cardiac output of 5.0 L/min. Which additional finding would indicate that his total
peripheral resistance (TPR) is elevated?
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:
MAP = CO × TPR. Given a normal CO (5 L/min) and an elevated MAP (95 mm Hg), TPR must be
elevated. Increased TPR is typical of hypertension and arteriolar vasoconstriction. A narrowed
pulse pressure (systolic minus diastolic) occurs when TPR is high, as in essential hypertension,
because increased afterload reduces the stroke volume somewhat and causes a higher diastolic
pressure relative to systolic. Pulse pressure = SV/arterial compliance; with high TPR, diastolic
runoff is slower, so diastolic pressure is higher, narrowing the pulse pressure.
• Option A (Decreased heart rate) – Heart rate is not directly determined by TPR. If
anything, a compensatory response to high TPR and hypertension may be a slight
increase or no change; not directly indicative.
• Option B (Elevated stroke volume) – If stroke volume increased, MAP would rise but
TPR could be normal or low. High TPR typically reduces stroke volume slightly due to
increased afterload. Not a finding that indicates elevated TPR.
• Option C (Narrowed pulse pressure) – Correct as explained. High systemic vascular
resistance elevates diastolic pressure more than systolic, causing the pulse pressure to
narrow.
pg. 4
COMSAE PHASE 1 FORM 114 Actual EXAM – 176
QUESTIONS AND ANSWERS | VERIFIED AND WELL
DETAILED ANSWERS | PLUS RATIONALES |
GUARANTEED PASS | LATEST EXAM UPDATE | STUVIA
VERIFIED | EXAM PREP | STUDY GUIDE | PRACTICE TEST
Question 1 – Microbiology / Pharmacology
A 68-year-old woman with chronic obstructive pulmonary disease (COPD) is hospitalized with
fever, productive cough, and a chest X-ray showing a right lower lobe infiltrate. Gram stain
reveals numerous neutrophils and lancet-shaped gram-positive diplococci. She has a history
of anaphylaxis after taking amoxicillin 10 years ago. Which antibiotic is contraindicated in this
patient?
A) Levofloxacin
B) Vancomycin
C) Cefazolin
D) Doxycycline
E) Azithromycin
:Answer: C – Cefazolin
Full Rationale:
• Option C (Cefazolin) is correct because cefazolin is a first-generation cephalosporin.
Cephalosporins share a beta-lactam ring structure with penicillins, and cross-reactivity
occurs in approximately 1–10% of penicillin-allergic patients. Given her history of
anaphylaxis (a severe, IgE-mediated reaction) to amoxicillin, cephalosporins should be
avoided unless skin testing confirms no allergy, and they are contraindicated in this
scenario.
• Option A (Levofloxacin) – A fluoroquinolone. It is not contraindicated based on
penicillin allergy; it is a safe alternative for CAP in penicillin-allergic patients. However, it
carries risks of tendonitis, QT prolongation, and C. difficile. Not the correct answer
because it is not contraindicated.
• Option B (Vancomycin) – A glycopeptide effective against gram-positive cocci
including Streptococcus pneumoniae. It has no cross-reactivity with penicillins. It can be
pg. 1
,2
used, though usually reserved for MRSA or severe penicillin-resistant pneumococcus.
Not contraindicated.
• Option D (Doxycycline) – A tetracycline antibiotic. No beta-lactam ring, so safe in
penicillin allergy. May be used for respiratory infections. Not contraindicated.
• Option E (Azithromycin) – A macrolide. Also safe in penicillin allergy, commonly used for
CAP. No cross-reactivity. Not contraindicated.
Key takeaway: A true penicillin allergy with anaphylaxis contraindicates the use of
cephalosporins due to potential cross-reactivity.
Question 2 – Pathology / Immunology
A 4-month-old infant is brought to the emergency department with severe diarrhea, oral
thrush, and failure to thrive. Laboratory findings show lymphopenia with absent T cells but
normal B cell counts. A chest X-ray reveals absence of a thymic shadow. Which
immunodeficiency disorder 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. DiGeorge syndrome (22q11.2 deletion) results
from abnormal development of the 3rd and 4th pharyngeal pouches, leading to thymic
aplasia (absent T cells), hypocalcemia (parathyroid hypoplasia), and cardiac anomalies.
The presentation of T-cell deficiency (oral thrush, failure to thrive, severe diarrhea),
absent thymic shadow, and lymphopenia with absent T cells is classic.
• Option A (CVID) – Presents later in life (adolescence or adulthood) with recurrent
sinopulmonary infections and autoimmune disease. Not associated with absent thymic
shadow or presentation at 4 months.
• Option B (X-linked agammaglobulinemia) – Bruton’s disease; blocks B cell maturation,
leading to absent B cells and very low immunoglobulins after maternal antibodies wane
(around 6 months). T cells are normal. Not fitting the absent T cells and thymic shadow.
pg. 2
,3
• Option D (Wiskott-Aldrich syndrome) – Characterized by the triad of eczema,
thrombocytopenia (small platelets), and recurrent infections. T cells may be affected but
not absent at birth; thymic shadow is present.
• Option E (Chronic granulomatous disease) – A defect in the NADPH oxidase pathway,
leading to inability of phagocytes to kill catalase-positive organisms. Not associated with
lymphopenia or absent thymus; presents with recurrent abscesses and granulomas.
Key takeaway: Thymic aplasia + absent T cells + hypocalcemia = DiGeorge syndrome.
Question 3 – Pharmacology / Neurology
A 60-year-old woman with Parkinson’s disease has been taking carbidopa-levodopa for 4
years. She develops distressing involuntary movements of the face and neck that subside
when the medication is withheld. Which term best describes this phenomenon?
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 dyskinesias are involuntary,
choreiform movements that occur as a peak-dose side effect. They are directly related
to dopamine receptor stimulation and improve when levodopa is reduced or withheld.
They are different from tardive dyskinesia which is caused by long-term antipsychotic
use.
• Option A (On-off phenomenon) – Fluctuations in motor response where the patient
cycles between “on” periods (good mobility) and “off” periods (hypomobile, stiff). Not a
description of involuntary movements per se, but rather the variability of therapeutic
effect.
• Option C (Akathisia) – A subjective sense of inner restlessness and an urge to move,
often seen with antipsychotic medications. Not facial/neck choreiform movements.
• Option D (Tardive dyskinesia) – Involuntary movements, often of the face (tongue
rolling, lip smacking), caused by chronic blockade of dopamine receptors (e.g., by
antipsychotics). It is not relieved by withholding levodopa; it is exacerbated by
dopamine antagonists.
pg. 3
, 4
• Option E (Dystonia) – Sustained or intermittent muscle contractions causing abnormal
postures or repetitive movements. Can be a complication of long-term levodopa
therapy, but usually occurs as an “off” period phenomenon (early morning dystonia).
The description of face/neck movements that subside when the drug is withheld points
to peak-dose dyskinesia.
Key takeaway: Levodopa-induced dyskinesias are hyperkinetic movements that appear at peak
drug levels and resolve when the dose is lowered or the drug is stopped.
Question 4 – Cardiology / Physiology
A 55-year-old man has a mean arterial pressure (MAP) of 95 mm Hg, a heart rate of 80 bpm,
and a cardiac output of 5.0 L/min. Which additional finding would indicate that his total
peripheral resistance (TPR) is elevated?
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:
MAP = CO × TPR. Given a normal CO (5 L/min) and an elevated MAP (95 mm Hg), TPR must be
elevated. Increased TPR is typical of hypertension and arteriolar vasoconstriction. A narrowed
pulse pressure (systolic minus diastolic) occurs when TPR is high, as in essential hypertension,
because increased afterload reduces the stroke volume somewhat and causes a higher diastolic
pressure relative to systolic. Pulse pressure = SV/arterial compliance; with high TPR, diastolic
runoff is slower, so diastolic pressure is higher, narrowing the pulse pressure.
• Option A (Decreased heart rate) – Heart rate is not directly determined by TPR. If
anything, a compensatory response to high TPR and hypertension may be a slight
increase or no change; not directly indicative.
• Option B (Elevated stroke volume) – If stroke volume increased, MAP would rise but
TPR could be normal or low. High TPR typically reduces stroke volume slightly due to
increased afterload. Not a finding that indicates elevated TPR.
• Option C (Narrowed pulse pressure) – Correct as explained. High systemic vascular
resistance elevates diastolic pressure more than systolic, causing the pulse pressure to
narrow.
pg. 4
