USMLE STEP 2 CK (CLINICAL
KNOWLEDGE) PRACTICE EXAM WITH 60
QUESTIONS. EACH QUESTION HAS
THE CORRECT ANSWER IN BOLD AND
THE RATIONALE IN ITALICS.
Question 1
A 45-year-old woman presents with a 3-month history of fatigue, arthralgias, and
a malar rash that worsens with sun exposure. Laboratory studies show ANA
positive (1:640), anti-dsDNA positive, and low C3/C4. Urinalysis shows proteinuria
(2+). Which medication is most appropriate as first-line therapy for her lupus
nephritis?
A) Hydroxychloroquine alone
B) Prednisone 20 mg daily alone
C) Mycophenolate mofetil
D) Cyclophosphamide
E) Azathioprine
Rationale: This patient has active lupus nephritis (proteinuria, low complement,
anti-dsDNA). For severe proliferative lupus nephritis (class III/IV), first-line
induction therapy is either mycophenolate mofetil or cyclophosphamide.
Cyclophosphamide is a standard choice; mycophenolate is also acceptable but
cyclophosphamide is the traditional answer.
Question 2
A 68-year-old man with a history of hypertension and type 2 diabetes presents
with sudden onset of right-sided weakness and aphasia. His symptoms began 1
,hour ago. His blood pressure is 185/100 mmHg. Non-contrast head CT shows no
hemorrhage. He has no contraindications to thrombolysis. What is the most
appropriate next step?
A) Aspirin 325 mg orally
B) Lower BP to <140/90 mmHg
C) IV alteplase (tPA)
D) Clopidogrel 300 mg load
E) Carotid endarterectomy
*Rationale: Within 3-4.5 hours of ischemic stroke onset with no hemorrhage on
CT and no contraindications, IV tPA is first-line. BP >185/110 is a relative
contraindication, but this patient’s BP is exactly the cutoff (185/100) and can be
managed with careful BP lowering before tPA if needed. However, current
guidelines recommend tPA if BP can be safely lowered to <185/110.*
Question 3
A 22-year-old woman with no significant medical history presents with acute-
onset shortness of breath and pleuritic chest pain. She is tachycardic and hypoxic.
She has a history of oral contraceptive use. A CT pulmonary angiogram shows a
filling defect in the left main pulmonary artery. What is the most appropriate
initial anticoagulation for this patient?
A) Warfarin monotherapy
B) Unfractionated heparin IV
C) Apixaban alone
D) Enoxaparin subcutaneously twice daily
E) Aspirin 325 mg
*Rationale: For acute pulmonary embolism with hemodynamic stability but
hypoxia, initial anticoagulation can be with LMWH, fondaparinux, or UFH.
Unfractionated heparin IV is often used if there is concern for hemodynamic
instability or if patient may need thrombolysis. However, apixaban or rivaroxaban
as monotherapy (without heparin bridging) are also first-line. On Step 2 CK, many
,choose LMWH (enoxaparin) or apixaban. Here, UFH is acceptable, but enoxaparin
is more common. Let’s adjust: The best initial is LMWH (enoxaparin) or apixaban.
Since options include both, apixaban is oral monotherapy. The most common
answer: enoxaparin. But Step 2 often tests direct oral anticoagulants. I’ll change
answer to Apixaban as first-line without heparin.
Corrected Answer: C) Apixaban alone
Rationale: Direct oral anticoagulants (apixaban, rivaroxaban) are first-line for
acute PE in stable patients without heparin bridging. Warfarin requires heparin
bridge.
Question 4
A 55-year-old man with a 40-pack-year smoking history presents with worsening
dyspnea on exertion, chronic cough, and weight loss. Spirometry shows FEV1/FVC
ratio of 0.65, FEV1 45% of predicted. He is up to date on vaccines. He continues to
smoke. What is the most effective intervention to reduce disease progression?
A) Inhaled corticosteroids
B) Long-acting beta agonist
C) Pulmonary rehabilitation
D) Smoking cessation
E) Long-term oxygen therapy
Rationale: In COPD, smoking cessation is the only intervention proven to slow
disease progression. Oxygen improves survival in hypoxemic patients but does not
slow progression.
Question 5
A 32-year-old woman at 28 weeks gestation presents with a 2-day history of
headache, blurred vision, and right upper quadrant pain. Her blood pressure is
, 165/105 mmHg. Urinalysis shows 3+ protein. Platelet count is 80,000/μL. AST is
120 U/L. What is the most appropriate next step?
A) Oral labetalol
B) Magnesium sulfate and delivery
C) Bed rest and close monitoring
D) Magnesium sulfate + antihypertensive + delivery after 48 hours of steroids
E) Nifedipine and outpatient follow-up
*Rationale: This patient has severe preeclampsia with HELLP syndrome
(thrombocytopenia, elevated LFTs). At 28 weeks, delivery is indicated after
maternal stabilization. Magnesium sulfate for seizure prophylaxis,
antihypertensives (labetalol/hydralazine), and antenatal corticosteroids for fetal
lung maturity before delivery.*
Question 6
A 70-year-old man with a history of atrial fibrillation on warfarin presents with
sudden onset of severe headache, nausea, and vomiting. Neurologic exam shows
left-sided weakness. INR is 4.5. Non-contrast head CT shows a large right-sided
intraparenchymal hemorrhage. Which medication should be given immediately?
A) Vitamin K IV
B) Fresh frozen plasma
C) Prothrombin complex concentrate (PCC)
D) Andexanet alfa
E) Protamine sulfate
*Rationale: For warfarin-associated intracranial hemorrhage, reversal with PCC (4-
factor) is preferred over FFP (faster, lower volume). Vitamin K is given but takes
hours. Andexanet is for direct Xa inhibitors, not warfarin.*
Question 7
KNOWLEDGE) PRACTICE EXAM WITH 60
QUESTIONS. EACH QUESTION HAS
THE CORRECT ANSWER IN BOLD AND
THE RATIONALE IN ITALICS.
Question 1
A 45-year-old woman presents with a 3-month history of fatigue, arthralgias, and
a malar rash that worsens with sun exposure. Laboratory studies show ANA
positive (1:640), anti-dsDNA positive, and low C3/C4. Urinalysis shows proteinuria
(2+). Which medication is most appropriate as first-line therapy for her lupus
nephritis?
A) Hydroxychloroquine alone
B) Prednisone 20 mg daily alone
C) Mycophenolate mofetil
D) Cyclophosphamide
E) Azathioprine
Rationale: This patient has active lupus nephritis (proteinuria, low complement,
anti-dsDNA). For severe proliferative lupus nephritis (class III/IV), first-line
induction therapy is either mycophenolate mofetil or cyclophosphamide.
Cyclophosphamide is a standard choice; mycophenolate is also acceptable but
cyclophosphamide is the traditional answer.
Question 2
A 68-year-old man with a history of hypertension and type 2 diabetes presents
with sudden onset of right-sided weakness and aphasia. His symptoms began 1
,hour ago. His blood pressure is 185/100 mmHg. Non-contrast head CT shows no
hemorrhage. He has no contraindications to thrombolysis. What is the most
appropriate next step?
A) Aspirin 325 mg orally
B) Lower BP to <140/90 mmHg
C) IV alteplase (tPA)
D) Clopidogrel 300 mg load
E) Carotid endarterectomy
*Rationale: Within 3-4.5 hours of ischemic stroke onset with no hemorrhage on
CT and no contraindications, IV tPA is first-line. BP >185/110 is a relative
contraindication, but this patient’s BP is exactly the cutoff (185/100) and can be
managed with careful BP lowering before tPA if needed. However, current
guidelines recommend tPA if BP can be safely lowered to <185/110.*
Question 3
A 22-year-old woman with no significant medical history presents with acute-
onset shortness of breath and pleuritic chest pain. She is tachycardic and hypoxic.
She has a history of oral contraceptive use. A CT pulmonary angiogram shows a
filling defect in the left main pulmonary artery. What is the most appropriate
initial anticoagulation for this patient?
A) Warfarin monotherapy
B) Unfractionated heparin IV
C) Apixaban alone
D) Enoxaparin subcutaneously twice daily
E) Aspirin 325 mg
*Rationale: For acute pulmonary embolism with hemodynamic stability but
hypoxia, initial anticoagulation can be with LMWH, fondaparinux, or UFH.
Unfractionated heparin IV is often used if there is concern for hemodynamic
instability or if patient may need thrombolysis. However, apixaban or rivaroxaban
as monotherapy (without heparin bridging) are also first-line. On Step 2 CK, many
,choose LMWH (enoxaparin) or apixaban. Here, UFH is acceptable, but enoxaparin
is more common. Let’s adjust: The best initial is LMWH (enoxaparin) or apixaban.
Since options include both, apixaban is oral monotherapy. The most common
answer: enoxaparin. But Step 2 often tests direct oral anticoagulants. I’ll change
answer to Apixaban as first-line without heparin.
Corrected Answer: C) Apixaban alone
Rationale: Direct oral anticoagulants (apixaban, rivaroxaban) are first-line for
acute PE in stable patients without heparin bridging. Warfarin requires heparin
bridge.
Question 4
A 55-year-old man with a 40-pack-year smoking history presents with worsening
dyspnea on exertion, chronic cough, and weight loss. Spirometry shows FEV1/FVC
ratio of 0.65, FEV1 45% of predicted. He is up to date on vaccines. He continues to
smoke. What is the most effective intervention to reduce disease progression?
A) Inhaled corticosteroids
B) Long-acting beta agonist
C) Pulmonary rehabilitation
D) Smoking cessation
E) Long-term oxygen therapy
Rationale: In COPD, smoking cessation is the only intervention proven to slow
disease progression. Oxygen improves survival in hypoxemic patients but does not
slow progression.
Question 5
A 32-year-old woman at 28 weeks gestation presents with a 2-day history of
headache, blurred vision, and right upper quadrant pain. Her blood pressure is
, 165/105 mmHg. Urinalysis shows 3+ protein. Platelet count is 80,000/μL. AST is
120 U/L. What is the most appropriate next step?
A) Oral labetalol
B) Magnesium sulfate and delivery
C) Bed rest and close monitoring
D) Magnesium sulfate + antihypertensive + delivery after 48 hours of steroids
E) Nifedipine and outpatient follow-up
*Rationale: This patient has severe preeclampsia with HELLP syndrome
(thrombocytopenia, elevated LFTs). At 28 weeks, delivery is indicated after
maternal stabilization. Magnesium sulfate for seizure prophylaxis,
antihypertensives (labetalol/hydralazine), and antenatal corticosteroids for fetal
lung maturity before delivery.*
Question 6
A 70-year-old man with a history of atrial fibrillation on warfarin presents with
sudden onset of severe headache, nausea, and vomiting. Neurologic exam shows
left-sided weakness. INR is 4.5. Non-contrast head CT shows a large right-sided
intraparenchymal hemorrhage. Which medication should be given immediately?
A) Vitamin K IV
B) Fresh frozen plasma
C) Prothrombin complex concentrate (PCC)
D) Andexanet alfa
E) Protamine sulfate
*Rationale: For warfarin-associated intracranial hemorrhage, reversal with PCC (4-
factor) is preferred over FFP (faster, lower volume). Vitamin K is given but takes
hours. Andexanet is for direct Xa inhibitors, not warfarin.*
Question 7
