COMSAE Form 110 – Complete Exam
with Answer Key & Step-by-Step
Explanations | Ideal for COMLEX Level 1
Review”
1. What is the most common cause of community-acquired pneumonia in
adults?
• A. Mycoplasma pneumoniae
• B. Streptococcus pneumoniae
• C. Haemophilus influenzae
• D. Staphylococcus aureus
Correct Answer: B. Streptococcus pneumoniae
Rationale: Streptococcus pneumoniae is the leading cause of
community-acquired pneumonia, accounting for the majority of bacterial
cases, particularly in adults. Mycoplasma pneumoniae is more common in
younger populations .
2. Which of the following is the primary site of erythropoietin production in
adults?
• A. Liver
• B. Kidney
• C. Spleen
• D. Bone marrow
Correct Answer: B. Kidney
Rationale: Erythropoietin is mainly produced by the interstitial
, fibroblasts of the kidney in response to hypoxia, stimulating red blood cell
production in the bone marrow .
3. A 25-year-old woman presents with heat intolerance, weight loss, and
palpitations. Which of the following is the most likely diagnosis?
• A. Hypothyroidism
• B. Hyperthyroidism
• C. Cushing’s syndrome
• D. Addison’s disease
Correct Answer: B. Hyperthyroidism
Rationale: The combination of heat intolerance, weight loss, and
palpitations points to hyperthyroidism, often caused by Graves’ disease in
young women .
4. Which of the following heart murmurs is best heard at the left lower sternal
border and increases with inspiration?
• A. Aortic stenosis
• B. Pulmonary stenosis
• C. Tricuspid regurgitation
• D. Mitral stenosis
Correct Answer: C. Tricuspid regurgitation
Rationale: Tricuspid regurgitation produces a holosystolic murmur best
heard at the left lower sternal border that increases with inspiration
(Carvallo’s sign) due to increased venous return .
5. What is the most common cause of subarachnoid hemorrhage?
• A. Trauma
• B. Hypertension
• C. Ruptured saccular aneurysm
, • D. Arteriovenous malformation
Correct Answer: C. Ruptured saccular aneurysm
Rationale: Rupture of a saccular (berry) aneurysm is the leading cause
of non-traumatic subarachnoid hemorrhage, often presenting with sudden
"thunderclap" headache .
6. Which vaccine is contraindicated in a pregnant woman?
• A. Influenza inactivated
• B. Tdap
• C. MMR
• D. Hepatitis B
Correct Answer: C. MMR
Rationale: Live attenuated vaccines such as MMR are contraindicated
in pregnancy due to potential teratogenicity, whereas inactivated vaccines
like influenza and Tdap are safe .
7. A 60-year-old man with chronic alcohol use presents with confusion,
ophthalmoplegia, and ataxia. The most likely diagnosis is:
• A. Korsakoff syndrome
• B. Wernicke encephalopathy
• C. Alcoholic cerebellar degeneration
• D. Hepatic encephalopathy
Correct Answer: B. Wernicke encephalopathy
Rationale: Wernicke encephalopathy is caused by thiamine deficiency,
presenting with the classic triad of ophthalmoplegia, ataxia, and confusion .
8. Which drug is first-line for an acute gout flare?
• A. Allopurinol
• B. Colchicine
• C. Probenecid
, • D. Febuxostat
Correct Answer: B. Colchicine
Rationale: Colchicine is used to treat acute gout attacks. Allopurinol
and febuxostat are urate-lowering therapies used for chronic management,
not for acute flares .
9. A patient with a history of a seizure disorder is started on a new medication
and develops a rash, fever, and lymphadenopathy. Which medication is most
likely responsible?
• A. Valproic acid
• B. Lamotrigine
• C. Phenytoin
• D. Levetiracetam
Correct Answer: C. Phenytoin
Rationale: Phenytoin can cause a hypersensitivity reaction presenting
with rash, fever, and lymphadenopathy, often occurring within 1-4 weeks of
starting therapy .
10. What is the hallmark of nephrotic syndrome?
• A. Hematuria
• B. Hypertension
• C. Proteinuria >3.5 g/day
• D. Oliguria
Correct Answer: C. Proteinuria >3.5 g/day
Rationale: Nephrotic syndrome is characterized by heavy proteinuria
(>3.5 g/day), hypoalbuminemia, edema, and hyperlipidemia. Hematuria and
hypertension are more typical of nephritic syndromes .
11. Which electrolyte abnormality is most commonly associated with
prolonged QT interval?
• A. Hypercalcemia
with Answer Key & Step-by-Step
Explanations | Ideal for COMLEX Level 1
Review”
1. What is the most common cause of community-acquired pneumonia in
adults?
• A. Mycoplasma pneumoniae
• B. Streptococcus pneumoniae
• C. Haemophilus influenzae
• D. Staphylococcus aureus
Correct Answer: B. Streptococcus pneumoniae
Rationale: Streptococcus pneumoniae is the leading cause of
community-acquired pneumonia, accounting for the majority of bacterial
cases, particularly in adults. Mycoplasma pneumoniae is more common in
younger populations .
2. Which of the following is the primary site of erythropoietin production in
adults?
• A. Liver
• B. Kidney
• C. Spleen
• D. Bone marrow
Correct Answer: B. Kidney
Rationale: Erythropoietin is mainly produced by the interstitial
, fibroblasts of the kidney in response to hypoxia, stimulating red blood cell
production in the bone marrow .
3. A 25-year-old woman presents with heat intolerance, weight loss, and
palpitations. Which of the following is the most likely diagnosis?
• A. Hypothyroidism
• B. Hyperthyroidism
• C. Cushing’s syndrome
• D. Addison’s disease
Correct Answer: B. Hyperthyroidism
Rationale: The combination of heat intolerance, weight loss, and
palpitations points to hyperthyroidism, often caused by Graves’ disease in
young women .
4. Which of the following heart murmurs is best heard at the left lower sternal
border and increases with inspiration?
• A. Aortic stenosis
• B. Pulmonary stenosis
• C. Tricuspid regurgitation
• D. Mitral stenosis
Correct Answer: C. Tricuspid regurgitation
Rationale: Tricuspid regurgitation produces a holosystolic murmur best
heard at the left lower sternal border that increases with inspiration
(Carvallo’s sign) due to increased venous return .
5. What is the most common cause of subarachnoid hemorrhage?
• A. Trauma
• B. Hypertension
• C. Ruptured saccular aneurysm
, • D. Arteriovenous malformation
Correct Answer: C. Ruptured saccular aneurysm
Rationale: Rupture of a saccular (berry) aneurysm is the leading cause
of non-traumatic subarachnoid hemorrhage, often presenting with sudden
"thunderclap" headache .
6. Which vaccine is contraindicated in a pregnant woman?
• A. Influenza inactivated
• B. Tdap
• C. MMR
• D. Hepatitis B
Correct Answer: C. MMR
Rationale: Live attenuated vaccines such as MMR are contraindicated
in pregnancy due to potential teratogenicity, whereas inactivated vaccines
like influenza and Tdap are safe .
7. A 60-year-old man with chronic alcohol use presents with confusion,
ophthalmoplegia, and ataxia. The most likely diagnosis is:
• A. Korsakoff syndrome
• B. Wernicke encephalopathy
• C. Alcoholic cerebellar degeneration
• D. Hepatic encephalopathy
Correct Answer: B. Wernicke encephalopathy
Rationale: Wernicke encephalopathy is caused by thiamine deficiency,
presenting with the classic triad of ophthalmoplegia, ataxia, and confusion .
8. Which drug is first-line for an acute gout flare?
• A. Allopurinol
• B. Colchicine
• C. Probenecid
, • D. Febuxostat
Correct Answer: B. Colchicine
Rationale: Colchicine is used to treat acute gout attacks. Allopurinol
and febuxostat are urate-lowering therapies used for chronic management,
not for acute flares .
9. A patient with a history of a seizure disorder is started on a new medication
and develops a rash, fever, and lymphadenopathy. Which medication is most
likely responsible?
• A. Valproic acid
• B. Lamotrigine
• C. Phenytoin
• D. Levetiracetam
Correct Answer: C. Phenytoin
Rationale: Phenytoin can cause a hypersensitivity reaction presenting
with rash, fever, and lymphadenopathy, often occurring within 1-4 weeks of
starting therapy .
10. What is the hallmark of nephrotic syndrome?
• A. Hematuria
• B. Hypertension
• C. Proteinuria >3.5 g/day
• D. Oliguria
Correct Answer: C. Proteinuria >3.5 g/day
Rationale: Nephrotic syndrome is characterized by heavy proteinuria
(>3.5 g/day), hypoalbuminemia, edema, and hyperlipidemia. Hematuria and
hypertension are more typical of nephritic syndromes .
11. Which electrolyte abnormality is most commonly associated with
prolonged QT interval?
• A. Hypercalcemia
