COMLEX-USA Level 3 → Final
Comprehensive Practice Exam
Questions With Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1.
A 68-year-old man with CHF presents with worsening dyspnea,
orthopnea, and bilateral leg swelling. On exam: crackles, elevated JVP,
and S3 gallop. What is the best initial pharmacologic treatment?
A. Digoxin
B. Furosemide
C. Metoprolol
D. Lisinopril
Correct Answer: B. Furosemide
Rationale: In acute decompensated heart failure with volume
overload, loop diuretics such as furosemide provide rapid symptom
relief by reducing preload and pulmonary congestion.
2.
,A 55-year-old man with long-standing smoking history presents with
hemoptysis and weight loss. Imaging reveals a central lung mass. Most
likely diagnosis?
A. Adenocarcinoma
B. Small cell carcinoma
C. Squamous cell carcinoma
D. Carcinoid tumor
Correct Answer: C. Squamous cell carcinoma
Rationale: Squamous cell carcinoma is strongly associated with
smoking and typically presents as a central lung lesion with possible
hemoptysis due to cavitation.
3.
A 23-year-old woman presents with dysuria and urinary frequency. UA
shows leukocyte esterase and nitrites. Best treatment?
A. Amoxicillin
B. Nitrofurantoin
C. Vancomycin
D. Fluconazole
Correct Answer: B. Nitrofurantoin
Rationale: Uncomplicated UTI in young women is best treated with
nitrofurantoin, which is effective against common gram-negative
uropathogens like E. coli.
,4.
A patient presents with severe watery diarrhea after recent antibiotic
use. Which organism is most likely?
A. Salmonella
B. Clostridioides difficile
C. Shigella
D. E. coli O157:H7
Correct Answer: B. Clostridioides difficile
Rationale: Recent antibiotic use disrupts gut flora allowing C. difficile
overgrowth leading to pseudomembranous colitis and watery
diarrhea.
5.
A 60-year-old man presents with tremor at rest, rigidity, and
bradykinesia. Pathology involves loss of which neurotransmitter?
A. Serotonin
B. Dopamine
C. Acetylcholine
D. GABA
Correct Answer: B. Dopamine
Rationale: Parkinson disease results from degeneration of
dopaminergic neurons in the substantia nigra pars compacta.
6.
, A child presents with barking cough and inspiratory stridor. Most
appropriate initial management?
A. IV antibiotics
B. Racemic epinephrine
C. Albuterol
D. Oxygen only
Correct Answer: B. Racemic epinephrine
Rationale: Croup is treated with racemic epinephrine for airway
edema and dexamethasone for inflammation.
7.
A patient has chest pain relieved by leaning forward. ECG shows diffuse
ST elevation. Diagnosis?
A. MI
B. Pericarditis
C. Aortic dissection
D. GERD
Correct Answer: B. Pericarditis
Rationale: Acute pericarditis presents with pleuritic chest pain relieved
by sitting forward and diffuse ST elevation on ECG.
8.
A 45-year-old alcoholic presents with confusion, ophthalmoplegia, and
ataxia. Treatment?
Comprehensive Practice Exam
Questions With Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1.
A 68-year-old man with CHF presents with worsening dyspnea,
orthopnea, and bilateral leg swelling. On exam: crackles, elevated JVP,
and S3 gallop. What is the best initial pharmacologic treatment?
A. Digoxin
B. Furosemide
C. Metoprolol
D. Lisinopril
Correct Answer: B. Furosemide
Rationale: In acute decompensated heart failure with volume
overload, loop diuretics such as furosemide provide rapid symptom
relief by reducing preload and pulmonary congestion.
2.
,A 55-year-old man with long-standing smoking history presents with
hemoptysis and weight loss. Imaging reveals a central lung mass. Most
likely diagnosis?
A. Adenocarcinoma
B. Small cell carcinoma
C. Squamous cell carcinoma
D. Carcinoid tumor
Correct Answer: C. Squamous cell carcinoma
Rationale: Squamous cell carcinoma is strongly associated with
smoking and typically presents as a central lung lesion with possible
hemoptysis due to cavitation.
3.
A 23-year-old woman presents with dysuria and urinary frequency. UA
shows leukocyte esterase and nitrites. Best treatment?
A. Amoxicillin
B. Nitrofurantoin
C. Vancomycin
D. Fluconazole
Correct Answer: B. Nitrofurantoin
Rationale: Uncomplicated UTI in young women is best treated with
nitrofurantoin, which is effective against common gram-negative
uropathogens like E. coli.
,4.
A patient presents with severe watery diarrhea after recent antibiotic
use. Which organism is most likely?
A. Salmonella
B. Clostridioides difficile
C. Shigella
D. E. coli O157:H7
Correct Answer: B. Clostridioides difficile
Rationale: Recent antibiotic use disrupts gut flora allowing C. difficile
overgrowth leading to pseudomembranous colitis and watery
diarrhea.
5.
A 60-year-old man presents with tremor at rest, rigidity, and
bradykinesia. Pathology involves loss of which neurotransmitter?
A. Serotonin
B. Dopamine
C. Acetylcholine
D. GABA
Correct Answer: B. Dopamine
Rationale: Parkinson disease results from degeneration of
dopaminergic neurons in the substantia nigra pars compacta.
6.
, A child presents with barking cough and inspiratory stridor. Most
appropriate initial management?
A. IV antibiotics
B. Racemic epinephrine
C. Albuterol
D. Oxygen only
Correct Answer: B. Racemic epinephrine
Rationale: Croup is treated with racemic epinephrine for airway
edema and dexamethasone for inflammation.
7.
A patient has chest pain relieved by leaning forward. ECG shows diffuse
ST elevation. Diagnosis?
A. MI
B. Pericarditis
C. Aortic dissection
D. GERD
Correct Answer: B. Pericarditis
Rationale: Acute pericarditis presents with pleuritic chest pain relieved
by sitting forward and diffuse ST elevation on ECG.
8.
A 45-year-old alcoholic presents with confusion, ophthalmoplegia, and
ataxia. Treatment?
