USMLE-Rx Step 1 Practice Q's

USMLE-Rx Step 1 Qmax Challenge #1497

Check out today’s Step 1 Qmax Question Challenge.

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USMLE-Rx Step 1 Qmax Challenge #1497A 54-year-old woman presents to the emergency department because of severe pain between her shoulder blades of 6 minutes’ duration. She states that she vomited on the way to the hospital. Her hands are clammy and she appears very anxious. An ECG from triage is shown in the image. The patient is given a medication that rapidly relieves her pain.

What is the mechanism of action of this medication?

A. Increased activity of guanylyl cyclase, leading to increased cGMP
B. Inhibition of angiotensin-converting enzyme
C. Inhibition of ascending pain pathway by binding to opioid receptors
D. Inhibition of the Na+/K+ ATP pump
E. Inhibition of transmembrane influx of Ca2+ into myocardial cells
F. Suppression of prostaglandin and thromboxane production

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5 replies »

  1. I think this ECG typically showing ST-elevation changes due to ischaemia.
    So, short acting NITRATES(eg:- GTN) are the best first line drugs to relive ischaemic pain.
    Nitrates have special MOA by producing Nitric Oxide(NO) that activates Guanylyl Cyclase which helps production of cGMP which further phosphorylates Myosin-Light Chain Kinase(MLCK) and thus causes vasodilation.

    So,answer should be (A)

    Liked by 1 person

  2. You give nitro to someone with chest pain and oncoming MI especially with the pain between the shoulder blades. Nitro acts on thro cGMP pathway and vasodialates

    Like

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