USMLE Step 1 Question 320

Question:

A 63-year-old man presents to the hospital with an extremely painful right big toe. He reports that the pain started last night and was unrelieved by pain medication. He denies any trauma to the toe. On exam, the right first metatarsophalangeal joint is red, swollen and extremely painful to palpation. Aspiration of the swollen joint reveals long, needle-shaped, negatively birefringent crystals under polarized light. Appropriate treatment is started, and the patient is told to avoid aspirin. For which of the following reasons is aspirin likely contraindicated in this patient?

Correct Answer: A.  Aspirin reduces renal clearance of uric acid

Aspirin is contraindicated in patients with gout because at low concentration, it can reduce renal clearance of uric acid and increase the hyperuricemia.

NSAIDS, such as indomethacin, are very effective for patients with gout for reducing inflammation and relieving pain, but this is not a reason why aspirin is contraindicated for patients with gout.

Aspirin would not provide adequate pain relief, but the reason why it is contraindicated is because of its effects on decreasing the clearance of uric acid.

Aspirin does not mobilize uric acid from body stores. This is the mechanism of action of uricosuric acids, such as probenecid.