USMLE Q Bank Step 2 CK- 406

A 35-year-old man with a history of Marfan syndrome presents to the emergency room complaining of chest pain radiating to his upper back between shoulder blades. His blood pressure is 170/90 mmHg in his right arm and 90/60 in left arm. His pulse is 98/min. Cardiac examination reveals regular rhythm with diastolic murmur on the left lower sternal border. Lung examination reveals clear bilateral breath sounds. An echocardiogram shows dissection of the thoracic aorta involving the left subclavian artery.

Which of these is the recommended immediate drug of choice?

A- Clopidogrel

B- Heparin

C- Sodium nitroprusside

D- Calcium gluconate

E- Labetalol


This is a typical presentation of aortic dissection. Labetalol is an alpha and beta adrenergic antagonist. It is the recommended drug of choice in this case. Sodium nitroprusside is contraindicated as its mechanism of action is dilation of blood vessels which could worsens the case.

The correct answer is E

5 thoughts on “USMLE Q Bank Step 2 CK- 406”

  1. vasodilatation so may worsens the case right ?

  2. Alpha and beta adrenergic antagonist is the drug that blacks the action of alpha and adrenergic receptors and antagonizes their actions. It their action is vasoconstriction then, the use of that drug leads to vasodilatation and vice versa. Thank you for your question.

  3. what is alpha and beta adrenergic antagonist

  4. Thank you so much

  5. very informative

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