American Board of Internal Medicine (ABIM) Certification Practice Exam

Which of the following is an alternative first-line therapy for urate lowering in patients with a history of hypersensitivity to allopurinol?

1. Febuxostat

2. Probenecid

3. Rasburicase

4. Indomethacin

The correct answer is: Febuxostat

Febuxostat is indeed an alternative first-line therapy for urate lowering in patients who have a history of hypersensitivity to allopurinol. Allopurinol works by inhibiting the enzyme xanthine oxidase, which plays a crucial role in the production of uric acid. When a patient has a hypersensitivity reaction to allopurinol, it is essential to find a safe alternative that can also effectively reduce uric acid levels. Febuxostat is another xanthine oxidase inhibitor but has a different chemical structure than allopurinol. This difference makes it less likely for patients with a history of allopurinol hypersensitivity to react adversely to febuxostat. Additionally, studies have shown that febuxostat is effective for managing hyperuricemia and can be used in the long term. While probenecid, rasburicase, and indomethacin are options that can also be utilized in the management of gout or hyperuricemia, they are generally not considered first-line alternatives specifically for those with allopurinol hypersensitivity. Probenecid works by increasing uric acid excretion in the kidneys, which may not be suitable for all patients, particularly those with renal impairment.