ESTUDYR
USMLE Step 1 Pharmacology: Advanced Clinical Integration &
Rapid High-Yield Review
1.
A 58-year-old man with long-standing hypertension is started on a medication that
competitively inhibits angiotensin-converting enzyme (ACE), thereby reducing angiotensin II
formation and decreasing aldosterone secretion. Which of the following is the most likely drug
prescribed?
A. Losartan
B. Spironolactone
C. Lisinopril
D. Amlodipine
E. Metoprolol
Correct Answer: C. Lisinopril
Rationale:
ACE inhibitors (e.g., lisinopril) block conversion of angiotensin I to angiotensin II, reducing
vasoconstriction and aldosterone release. Losartan is an ARB (blocks receptor, not enzyme).
2.
A patient taking lisinopril develops a persistent dry cough. This adverse effect is most likely due
to accumulation of:
A. Angiotensin I
B. Aldosterone
C. Bradykinin
D. Renin
E. Dopamine
Correct Answer: C
Rationale:
ACE also degrades bradykinin. Inhibition increases bradykinin → cough and angioedema.
,ESTUDYR
3.
A 65-year-old man with atrial fibrillation is prescribed a medication that competitively inhibits
vitamin K epoxide reductase, reducing activation of clotting factors II, VII, IX, and X. Which drug
is this?
A. Heparin
B. Apixaban
C. Aspirin
D. Warfarin
E. Clopidogrel
Correct Answer: D
Rationale:
Warfarin inhibits vitamin K recycling → reduced synthesis of vitamin K–dependent clotting
factors.
4.
Heparin exerts its anticoagulant effect primarily by:
A. Blocking platelet aggregation
B. Directly inhibiting thrombin
C. Enhancing antithrombin III activity
D. Inhibiting vitamin K
E. Blocking factor VII
Correct Answer: C
Rationale:
Heparin potentiates antithrombin III → inactivates thrombin and factor Xa.
5.
A patient with chest pain is given nitroglycerin. Its primary mechanism of action involves:
A. Beta-1 blockade
B. Calcium channel inhibition
C. Nitric oxide–mediated venodilation
, ESTUDYR
D. Sodium channel blockade
E. ACE inhibition
Correct Answer: C
Rationale:
Nitroglycerin releases NO → increases cGMP → venodilation → decreased preload.
6.
Which beta-blocker is selective for β1 receptors?
A. Propranolol
B. Carvedilol
C. Nadolol
D. Metoprolol
E. Timolol
Correct Answer: D
7.
A patient with asthma should avoid which medication due to risk of bronchospasm?
A. Metoprolol
B. Propranolol
C. Lisinopril
D. Amlodipine
E. Losartan
Correct Answer: B
Rationale:
Propranolol is nonselective (β1 + β2 blockade) → β2 blockade can cause bronchoconstriction.
8.
A 72-year-old patient develops lower extremity edema after starting antihypertensive therapy.
Which drug is most associated with peripheral edema?
USMLE Step 1 Pharmacology: Advanced Clinical Integration &
Rapid High-Yield Review
1.
A 58-year-old man with long-standing hypertension is started on a medication that
competitively inhibits angiotensin-converting enzyme (ACE), thereby reducing angiotensin II
formation and decreasing aldosterone secretion. Which of the following is the most likely drug
prescribed?
A. Losartan
B. Spironolactone
C. Lisinopril
D. Amlodipine
E. Metoprolol
Correct Answer: C. Lisinopril
Rationale:
ACE inhibitors (e.g., lisinopril) block conversion of angiotensin I to angiotensin II, reducing
vasoconstriction and aldosterone release. Losartan is an ARB (blocks receptor, not enzyme).
2.
A patient taking lisinopril develops a persistent dry cough. This adverse effect is most likely due
to accumulation of:
A. Angiotensin I
B. Aldosterone
C. Bradykinin
D. Renin
E. Dopamine
Correct Answer: C
Rationale:
ACE also degrades bradykinin. Inhibition increases bradykinin → cough and angioedema.
,ESTUDYR
3.
A 65-year-old man with atrial fibrillation is prescribed a medication that competitively inhibits
vitamin K epoxide reductase, reducing activation of clotting factors II, VII, IX, and X. Which drug
is this?
A. Heparin
B. Apixaban
C. Aspirin
D. Warfarin
E. Clopidogrel
Correct Answer: D
Rationale:
Warfarin inhibits vitamin K recycling → reduced synthesis of vitamin K–dependent clotting
factors.
4.
Heparin exerts its anticoagulant effect primarily by:
A. Blocking platelet aggregation
B. Directly inhibiting thrombin
C. Enhancing antithrombin III activity
D. Inhibiting vitamin K
E. Blocking factor VII
Correct Answer: C
Rationale:
Heparin potentiates antithrombin III → inactivates thrombin and factor Xa.
5.
A patient with chest pain is given nitroglycerin. Its primary mechanism of action involves:
A. Beta-1 blockade
B. Calcium channel inhibition
C. Nitric oxide–mediated venodilation
, ESTUDYR
D. Sodium channel blockade
E. ACE inhibition
Correct Answer: C
Rationale:
Nitroglycerin releases NO → increases cGMP → venodilation → decreased preload.
6.
Which beta-blocker is selective for β1 receptors?
A. Propranolol
B. Carvedilol
C. Nadolol
D. Metoprolol
E. Timolol
Correct Answer: D
7.
A patient with asthma should avoid which medication due to risk of bronchospasm?
A. Metoprolol
B. Propranolol
C. Lisinopril
D. Amlodipine
E. Losartan
Correct Answer: B
Rationale:
Propranolol is nonselective (β1 + β2 blockade) → β2 blockade can cause bronchoconstriction.
8.
A 72-year-old patient develops lower extremity edema after starting antihypertensive therapy.
Which drug is most associated with peripheral edema?
