COMAT Internal Medicine Exam V3 | COMAT
Internal Medicine | Q&A with Rationale (COMAT
Internal Medicine Exam) | National Board of
Osteopathic Medical Examiners (NBOME)
1. A 65-year-old male presents to the emergency department with a 3-day history of
worsening shortness of breath and orthopnea. On physical examination, he has bibasilar
crackles, a third heart sound (S3), and 3+ pitting edema of the lower extremities. His blood
pressure is 155/90 mmHg. Which of the following is the most appropriate initial
pharmacological treatment?
A. Lisinopril
B. Metoprolol
C. Spironolactone
D. Furosemide
Correct Answer: D
Explanation: This patient presents with signs of acute decompensated heart failure with
volume overload as evidenced by S3 and peripheral edema. Loop diuretics like furosemide
are the first-line treatment to rapidly reduce preload and alleviate pulmonary congestion.
Although ACE inhibitors and beta-blockers are essential for long-term survival, they do not
address acute volume overload and may worsen status if used aggressively during the
acute phase.
,2. A 72-year-old male with a 50 pack-year smoking history presents with chronic cough and
exertional dyspnea. Pulmonary function testing reveals an FEV1/FVC ratio of 0.60. He
currently uses an albuterol inhaler as needed but still experiences frequent symptoms. What
is the most appropriate next step in his management?
A. Inhaled corticosteroids
B. Theophylline
C. Long-acting muscarinic antagonist (LAMA)
D. Chronic oral prednisone
Correct Answer: C
Explanation: The patient has COPD confirmed by an FEV1/FVC ratio of less than 0.70. For
patients with persistent symptoms despite SABA use, a long-acting bronchodilator such as
a LAMA or LABA is indicated according to GOLD guidelines. Long-acting muscarinic
antagonists are particularly effective at reducing exacerbation frequency and improving
exercise tolerance in stable COPD patients.
3. A 45-year-old female is evaluated for routine health maintenance. She has a BMI of 32
kg/m² and a family history of diabetes. Her laboratory results show a fasting plasma glucose
of 135 mg/dL on two separate occasions and an HbA1c of 7.2%. After initiating lifestyle
modifications, which medication is the preferred first-line agent?
A. Pioglitazone
B. Glyburide
,C. Sitagliptin
D. Metformin
Correct Answer: D
Explanation: Metformin is the first-line pharmacologic treatment for Type 2 Diabetes
Mellitus due to its efficacy, safety profile, and weight-neutral or weight-loss benefits. It
primarily works by inhibiting hepatic gluconeogenesis and improving insulin sensitivity.
Clinical decision-making emphasizes Metformin unless contraindications like significant
renal impairment (eGFR < 30) are present.
4. A 58-year-old male with known cirrhosis due to chronic hepatitis C presents with
abdominal pain and low-grade fever. Abdominal paracentesis is performed, showing a total
protein of 1.2 g/dL and an absolute neutrophil count (ANC) of 350 cells/mm³. Which of the
following is the treatment of choice?
A. Oral Ciprofloxacin
B. Intravenous Cefotaxime
C. Intravenous Metronidazole
D. Intravenous Vancomycin
Correct Answer: B
Explanation: Spontaneous bacterial peritonitis (SBP) is diagnosed when the ascitic fluid
ANC is 250 cells/mm³ or higher. Third-generation cephalosporins, such as cefotaxime, are
the empirically preferred treatment because they cover common Gram-negative organisms
, like E. coli. Failure to treat SBP promptly can lead to sepsis and hepato-renal syndrome,
significantly increasing mortality.
5. A 34-year-old male presents with a cough productive of rust-colored sputum, high fever,
and pleuritic chest pain. Chest X-ray shows a right lower lobe consolidation. He has no
significant past medical history and has not used antibiotics recently. Which antibiotic is
appropriate for outpatient management?
A. Ciprofloxacin
B. Azithromycin
C. Trimethoprim-sulfamethoxazole
D. Penicillin V
Correct Answer: B
Explanation: This patient has community-acquired pneumonia (CAP), likely caused by
Streptococcus pneumoniae. For previously healthy outpatients with no risk factors for
MRSA or Pseudomonas, macrolides (like azithromycin) or doxycycline are historically
recommended. Clinicians must monitor local resistance patterns, as macrolide resistance is
increasing in some regions.
6. A 78-year-old female undergoes a CT scan with intravenous contrast for suspected bowel
obstruction. Two days later, her serum creatinine rises from 1.0 mg/dL to 2.4 mg/dL.
Urinalysis reveals ‘muddy brown’ granular casts. What is the most likely diagnosis?
A. Prerenal azotemia
Internal Medicine | Q&A with Rationale (COMAT
Internal Medicine Exam) | National Board of
Osteopathic Medical Examiners (NBOME)
1. A 65-year-old male presents to the emergency department with a 3-day history of
worsening shortness of breath and orthopnea. On physical examination, he has bibasilar
crackles, a third heart sound (S3), and 3+ pitting edema of the lower extremities. His blood
pressure is 155/90 mmHg. Which of the following is the most appropriate initial
pharmacological treatment?
A. Lisinopril
B. Metoprolol
C. Spironolactone
D. Furosemide
Correct Answer: D
Explanation: This patient presents with signs of acute decompensated heart failure with
volume overload as evidenced by S3 and peripheral edema. Loop diuretics like furosemide
are the first-line treatment to rapidly reduce preload and alleviate pulmonary congestion.
Although ACE inhibitors and beta-blockers are essential for long-term survival, they do not
address acute volume overload and may worsen status if used aggressively during the
acute phase.
,2. A 72-year-old male with a 50 pack-year smoking history presents with chronic cough and
exertional dyspnea. Pulmonary function testing reveals an FEV1/FVC ratio of 0.60. He
currently uses an albuterol inhaler as needed but still experiences frequent symptoms. What
is the most appropriate next step in his management?
A. Inhaled corticosteroids
B. Theophylline
C. Long-acting muscarinic antagonist (LAMA)
D. Chronic oral prednisone
Correct Answer: C
Explanation: The patient has COPD confirmed by an FEV1/FVC ratio of less than 0.70. For
patients with persistent symptoms despite SABA use, a long-acting bronchodilator such as
a LAMA or LABA is indicated according to GOLD guidelines. Long-acting muscarinic
antagonists are particularly effective at reducing exacerbation frequency and improving
exercise tolerance in stable COPD patients.
3. A 45-year-old female is evaluated for routine health maintenance. She has a BMI of 32
kg/m² and a family history of diabetes. Her laboratory results show a fasting plasma glucose
of 135 mg/dL on two separate occasions and an HbA1c of 7.2%. After initiating lifestyle
modifications, which medication is the preferred first-line agent?
A. Pioglitazone
B. Glyburide
,C. Sitagliptin
D. Metformin
Correct Answer: D
Explanation: Metformin is the first-line pharmacologic treatment for Type 2 Diabetes
Mellitus due to its efficacy, safety profile, and weight-neutral or weight-loss benefits. It
primarily works by inhibiting hepatic gluconeogenesis and improving insulin sensitivity.
Clinical decision-making emphasizes Metformin unless contraindications like significant
renal impairment (eGFR < 30) are present.
4. A 58-year-old male with known cirrhosis due to chronic hepatitis C presents with
abdominal pain and low-grade fever. Abdominal paracentesis is performed, showing a total
protein of 1.2 g/dL and an absolute neutrophil count (ANC) of 350 cells/mm³. Which of the
following is the treatment of choice?
A. Oral Ciprofloxacin
B. Intravenous Cefotaxime
C. Intravenous Metronidazole
D. Intravenous Vancomycin
Correct Answer: B
Explanation: Spontaneous bacterial peritonitis (SBP) is diagnosed when the ascitic fluid
ANC is 250 cells/mm³ or higher. Third-generation cephalosporins, such as cefotaxime, are
the empirically preferred treatment because they cover common Gram-negative organisms
, like E. coli. Failure to treat SBP promptly can lead to sepsis and hepato-renal syndrome,
significantly increasing mortality.
5. A 34-year-old male presents with a cough productive of rust-colored sputum, high fever,
and pleuritic chest pain. Chest X-ray shows a right lower lobe consolidation. He has no
significant past medical history and has not used antibiotics recently. Which antibiotic is
appropriate for outpatient management?
A. Ciprofloxacin
B. Azithromycin
C. Trimethoprim-sulfamethoxazole
D. Penicillin V
Correct Answer: B
Explanation: This patient has community-acquired pneumonia (CAP), likely caused by
Streptococcus pneumoniae. For previously healthy outpatients with no risk factors for
MRSA or Pseudomonas, macrolides (like azithromycin) or doxycycline are historically
recommended. Clinicians must monitor local resistance patterns, as macrolide resistance is
increasing in some regions.
6. A 78-year-old female undergoes a CT scan with intravenous contrast for suspected bowel
obstruction. Two days later, her serum creatinine rises from 1.0 mg/dL to 2.4 mg/dL.
Urinalysis reveals ‘muddy brown’ granular casts. What is the most likely diagnosis?
A. Prerenal azotemia
