COSMAE COMPLETE EXAM QUESTIONS WITH VERIFIED ANSWERS -
UPDATED EDITION 2026/2027
Q1. A 55-year-old man presents with chest pain radiating to the left arm,
diaphoresis, and nausea. ECG shows ST elevation in leads II, III, and aVF.
Which coronary artery is most likely occluded?
Answer: Right coronary artery (RCA). ST elevation in the inferior leads
(II, III, aVF) indicates an inferior STEMI, typically caused by RCA
occlusion. The RCA supplies the inferior wall, SA node, and AV node in
most individuals.
Q2. A patient with chronic kidney disease has a potassium of 6.2 mEq/L
with peaked T waves on ECG. What is the most appropriate immediate
treatment?
Answer: Intravenous calcium gluconate to stabilize the cardiac
membrane. This is followed by sodium bicarbonate and insulin/dextrose
to shift potassium intracellularly, then sodium polystyrene sulfonate or
dialysis for definitive removal.
Q3. A 42-year-old woman presents with fatigue, weight gain, constipation,
and cold intolerance. TSH is 12 mIU/L and free T4 is low. What is the
diagnosis and treatment?
Answer: Primary hypothyroidism. Treatment is levothyroxine (T4
replacement). TSH should be rechecked in 6-8 weeks after initiation or
dose adjustment. Target TSH is 0.5–2.5 mIU/L for most patients.
Q4. Which finding is most characteristic of cardiac tamponade on physical
examination?
, Answer: Beck's triad: hypotension, elevated JVD (jugular venous
distension), and muffled heart sounds. Also associated with pulsus
paradoxus (>10 mmHg drop in systolic BP during inspiration).
Q5. A 60-year-old smoker with COPD presents with worsening dyspnea,
productive cough, and fever. Sputum culture grows Haemophilus
influenzae. What is the first-line antibiotic?
Answer: Amoxicillin-clavulanate or azithromycin for outpatient
management of acute exacerbation of COPD. For H. influenzae
specifically, amoxicillin-clavulanate is preferred due to beta-lactamase
production. Fluoroquinolones are alternatives.
Q6. What is the mechanism of action of metformin in type 2 diabetes?
Answer: Metformin activates AMP-activated protein kinase (AMPK),
which decreases hepatic gluconeogenesis and glucose output from the
liver. It also increases peripheral glucose uptake and insulin sensitivity. It
does not stimulate insulin secretion and has low risk of hypoglycemia.
Q7. A patient is found to have a microcytic, hypochromic anemia with low
serum iron, low ferritin, and elevated TIBC. What is the diagnosis?
Answer: Iron deficiency anemia. Low ferritin is the most
sensitive/specific marker. Elevated TIBC reflects increased transferrin
production in response to iron deficiency. Common causes include
chronic blood loss (GI or menstrual), poor dietary intake, or
malabsorption.
Q8. Which medication is contraindicated in a patient with acute
decompensated heart failure?
Answer: Calcium channel blockers (particularly diltiazem and verapamil)
with negative inotropic effects are contraindicated. NSAIDs,
thiazolidinediones, and most antiarrhythmics should also be avoided.
Beta-blockers should not be initiated during acute decompensation.
Q9. A 45-year-old patient with alcoholic cirrhosis presents with confusion
and asterixis. Ammonia is elevated. What is the diagnosis and treatment?
Answer: Hepatic encephalopathy. Treatment includes lactulose (reduces
ammonia absorption) and rifaximin (reduces ammonia-producing gut
bacteria). Identify and treat precipitating causes such as GI bleeding,
infection, constipation, or electrolyte disturbances.
,Q10. What is the most common cause of community-acquired pneumonia
in adults?
Answer: Streptococcus pneumoniae is the most common cause. Other
common pathogens include Mycoplasma pneumoniae (atypical),
Haemophilus influenzae, Chlamydophila pneumoniae, and respiratory
viruses. Empiric treatment typically covers both typical and atypical
organisms.
Q11. A patient with atrial fibrillation has a CHA2DS2-VASc score of 3. What
anticoagulation is recommended?
Answer: Oral anticoagulation is strongly recommended (score ≥2 in
men, ≥3 in women). Direct oral anticoagulants (DOACs) such as
apixaban, rivaroxaban, or dabigatran are preferred over warfarin for non-
valvular atrial fibrillation due to better safety profiles.
Q12. Which electrolyte abnormality is most associated with prolonged QT
interval on ECG?
Answer: Hypokalemia, hypomagnesemia, and hypocalcemia can all
prolong the QT interval. Hypomagnesemia is the most important to
correct because hypokalemia is refractory to treatment without adequate
magnesium. Always check and replace magnesium in patients with
prolonged QT.
Q13. A patient presents with hematuria, proteinuria, and hypertension 2
weeks after a streptococcal throat infection. What is the most likely
diagnosis?
Answer: Post-streptococcal glomerulonephritis (PSGN). Caused by
immune complex deposition in glomeruli. Complement levels (C3) are
low. Treatment is supportive; most cases resolve spontaneously. RBC
casts in urine are characteristic.
Q14. What is the diagnostic criteria for metabolic syndrome?
Answer: Three or more of the following: waist circumference >102 cm
(men) or >88 cm (women); triglycerides ≥150 mg/dL; HDL <40 mg/dL
(men) or <50 mg/dL (women); BP ≥130/85 mmHg; fasting glucose ≥100
mg/dL.
Q15. A 58-year-old with rheumatoid arthritis on methotrexate presents with
macrocytic anemia. What is the mechanism?
, Answer: Methotrexate inhibits dihydrofolate reductase, blocking folate
metabolism and causing folate deficiency. Treatment includes folic acid
supplementation (1 mg/day) given on non-methotrexate days. Leucovorin
rescue is used for toxicity.
Q16. What is the classic triad of findings in infective endocarditis?
Answer: Fever, new or changing heart murmur, and positive blood
cultures. Duke criteria are used for diagnosis, requiring 2 major criteria, 1
major + 3 minor, or 5 minor criteria. Major criteria include positive blood
cultures and echocardiographic evidence of endocarditis.
Q17. A 35-year-old African American woman presents with bilateral hilar
lymphadenopathy, erythema nodosum, and uveitis. What is the diagnosis?
Answer: Sarcoidosis. Löfgren syndrome is the acute presentation with
bilateral hilar adenopathy, erythema nodosum, and arthritis/uveitis. ACE
levels may be elevated. Tissue biopsy showing non-caseating
granulomas confirms diagnosis.
Q18. Which test is the gold standard for diagnosing H. pylori infection in a
patient who has not taken antibiotics or PPIs recently?
Answer: Urea breath test or stool antigen test (non-invasive, high
sensitivity/specificity). Endoscopic biopsy with rapid urease test,
histology, or culture is used when endoscopy is indicated. Serology is
least useful (cannot distinguish active from past infection).
Q19. A patient with DKA has a serum sodium of 128 mEq/L. How do you
interpret this?
Answer: In DKA, hyperglycemia causes osmotic shift of water from
intracellular to extracellular, diluting serum sodium. Correct sodium by
adding 1.6 mEq/L for every 100 mg/dL glucose above 100. The corrected
sodium may actually be normal or elevated, guiding fluid and insulin
therapy.
Q20. What is the mechanism of action of spironolactone and when is it
used in heart failure?
Answer: Spironolactone is an aldosterone antagonist that blocks the
mineralocorticoid receptor, reducing sodium retention, potassium
excretion, and myocardial fibrosis. It is indicated in HFrEF (EF <35%)
UPDATED EDITION 2026/2027
Q1. A 55-year-old man presents with chest pain radiating to the left arm,
diaphoresis, and nausea. ECG shows ST elevation in leads II, III, and aVF.
Which coronary artery is most likely occluded?
Answer: Right coronary artery (RCA). ST elevation in the inferior leads
(II, III, aVF) indicates an inferior STEMI, typically caused by RCA
occlusion. The RCA supplies the inferior wall, SA node, and AV node in
most individuals.
Q2. A patient with chronic kidney disease has a potassium of 6.2 mEq/L
with peaked T waves on ECG. What is the most appropriate immediate
treatment?
Answer: Intravenous calcium gluconate to stabilize the cardiac
membrane. This is followed by sodium bicarbonate and insulin/dextrose
to shift potassium intracellularly, then sodium polystyrene sulfonate or
dialysis for definitive removal.
Q3. A 42-year-old woman presents with fatigue, weight gain, constipation,
and cold intolerance. TSH is 12 mIU/L and free T4 is low. What is the
diagnosis and treatment?
Answer: Primary hypothyroidism. Treatment is levothyroxine (T4
replacement). TSH should be rechecked in 6-8 weeks after initiation or
dose adjustment. Target TSH is 0.5–2.5 mIU/L for most patients.
Q4. Which finding is most characteristic of cardiac tamponade on physical
examination?
, Answer: Beck's triad: hypotension, elevated JVD (jugular venous
distension), and muffled heart sounds. Also associated with pulsus
paradoxus (>10 mmHg drop in systolic BP during inspiration).
Q5. A 60-year-old smoker with COPD presents with worsening dyspnea,
productive cough, and fever. Sputum culture grows Haemophilus
influenzae. What is the first-line antibiotic?
Answer: Amoxicillin-clavulanate or azithromycin for outpatient
management of acute exacerbation of COPD. For H. influenzae
specifically, amoxicillin-clavulanate is preferred due to beta-lactamase
production. Fluoroquinolones are alternatives.
Q6. What is the mechanism of action of metformin in type 2 diabetes?
Answer: Metformin activates AMP-activated protein kinase (AMPK),
which decreases hepatic gluconeogenesis and glucose output from the
liver. It also increases peripheral glucose uptake and insulin sensitivity. It
does not stimulate insulin secretion and has low risk of hypoglycemia.
Q7. A patient is found to have a microcytic, hypochromic anemia with low
serum iron, low ferritin, and elevated TIBC. What is the diagnosis?
Answer: Iron deficiency anemia. Low ferritin is the most
sensitive/specific marker. Elevated TIBC reflects increased transferrin
production in response to iron deficiency. Common causes include
chronic blood loss (GI or menstrual), poor dietary intake, or
malabsorption.
Q8. Which medication is contraindicated in a patient with acute
decompensated heart failure?
Answer: Calcium channel blockers (particularly diltiazem and verapamil)
with negative inotropic effects are contraindicated. NSAIDs,
thiazolidinediones, and most antiarrhythmics should also be avoided.
Beta-blockers should not be initiated during acute decompensation.
Q9. A 45-year-old patient with alcoholic cirrhosis presents with confusion
and asterixis. Ammonia is elevated. What is the diagnosis and treatment?
Answer: Hepatic encephalopathy. Treatment includes lactulose (reduces
ammonia absorption) and rifaximin (reduces ammonia-producing gut
bacteria). Identify and treat precipitating causes such as GI bleeding,
infection, constipation, or electrolyte disturbances.
,Q10. What is the most common cause of community-acquired pneumonia
in adults?
Answer: Streptococcus pneumoniae is the most common cause. Other
common pathogens include Mycoplasma pneumoniae (atypical),
Haemophilus influenzae, Chlamydophila pneumoniae, and respiratory
viruses. Empiric treatment typically covers both typical and atypical
organisms.
Q11. A patient with atrial fibrillation has a CHA2DS2-VASc score of 3. What
anticoagulation is recommended?
Answer: Oral anticoagulation is strongly recommended (score ≥2 in
men, ≥3 in women). Direct oral anticoagulants (DOACs) such as
apixaban, rivaroxaban, or dabigatran are preferred over warfarin for non-
valvular atrial fibrillation due to better safety profiles.
Q12. Which electrolyte abnormality is most associated with prolonged QT
interval on ECG?
Answer: Hypokalemia, hypomagnesemia, and hypocalcemia can all
prolong the QT interval. Hypomagnesemia is the most important to
correct because hypokalemia is refractory to treatment without adequate
magnesium. Always check and replace magnesium in patients with
prolonged QT.
Q13. A patient presents with hematuria, proteinuria, and hypertension 2
weeks after a streptococcal throat infection. What is the most likely
diagnosis?
Answer: Post-streptococcal glomerulonephritis (PSGN). Caused by
immune complex deposition in glomeruli. Complement levels (C3) are
low. Treatment is supportive; most cases resolve spontaneously. RBC
casts in urine are characteristic.
Q14. What is the diagnostic criteria for metabolic syndrome?
Answer: Three or more of the following: waist circumference >102 cm
(men) or >88 cm (women); triglycerides ≥150 mg/dL; HDL <40 mg/dL
(men) or <50 mg/dL (women); BP ≥130/85 mmHg; fasting glucose ≥100
mg/dL.
Q15. A 58-year-old with rheumatoid arthritis on methotrexate presents with
macrocytic anemia. What is the mechanism?
, Answer: Methotrexate inhibits dihydrofolate reductase, blocking folate
metabolism and causing folate deficiency. Treatment includes folic acid
supplementation (1 mg/day) given on non-methotrexate days. Leucovorin
rescue is used for toxicity.
Q16. What is the classic triad of findings in infective endocarditis?
Answer: Fever, new or changing heart murmur, and positive blood
cultures. Duke criteria are used for diagnosis, requiring 2 major criteria, 1
major + 3 minor, or 5 minor criteria. Major criteria include positive blood
cultures and echocardiographic evidence of endocarditis.
Q17. A 35-year-old African American woman presents with bilateral hilar
lymphadenopathy, erythema nodosum, and uveitis. What is the diagnosis?
Answer: Sarcoidosis. Löfgren syndrome is the acute presentation with
bilateral hilar adenopathy, erythema nodosum, and arthritis/uveitis. ACE
levels may be elevated. Tissue biopsy showing non-caseating
granulomas confirms diagnosis.
Q18. Which test is the gold standard for diagnosing H. pylori infection in a
patient who has not taken antibiotics or PPIs recently?
Answer: Urea breath test or stool antigen test (non-invasive, high
sensitivity/specificity). Endoscopic biopsy with rapid urease test,
histology, or culture is used when endoscopy is indicated. Serology is
least useful (cannot distinguish active from past infection).
Q19. A patient with DKA has a serum sodium of 128 mEq/L. How do you
interpret this?
Answer: In DKA, hyperglycemia causes osmotic shift of water from
intracellular to extracellular, diluting serum sodium. Correct sodium by
adding 1.6 mEq/L for every 100 mg/dL glucose above 100. The corrected
sodium may actually be normal or elevated, guiding fluid and insulin
therapy.
Q20. What is the mechanism of action of spironolactone and when is it
used in heart failure?
Answer: Spironolactone is an aldosterone antagonist that blocks the
mineralocorticoid receptor, reducing sodium retention, potassium
excretion, and myocardial fibrosis. It is indicated in HFrEF (EF <35%)
