However, febuxostat is more expensive than allopurinol because it is a newer drug still under patent in the U.S., says Dr. Choi. According to Dr. Choi, febuxostat costs about $2,385 wholesale per year, and the annual cost of allopurinol is less than $96.
Probenecid, another alternative ULD that increases the excretion of uric acid in the urine, tends to be less effective and is associated with more frequent drug interactions, adds Dr. Choi.
Another xanthine oxidase inhibitor, benzbromarone, has not been approved by the FDA because of reports of acute liver injury and deaths with its use.
In December 2015, the FDA approved lesinurad, which increases the excretion of uric acid in the urine, for use in combination with a xanthine oxidase inhibitor to treat gout. The FDA’s approval is based on data from three Phase 3 studies that included a total of 1,537 gout patients treated with combination urate-lowering therapy.
Because allopurinol remains the drug of choice for the vast majority of gout patients in the U.S., Dr. Choi’s paper points to the value of studying the potential impact of other known risk factors for SJS/TEN. To this end, his team is expanding its focus beyond race and ethnicity to sex, age and other co-morbidities that may increase the risk of severe adverse events. He hopes that results of the ongoing study will comprehensively aid risk stratification of patients taking allopurinol.
In the meantime, Dr. Choi urges rheumatologists and other physicians who care for gout patients or prescribe allopurinol for other purposes to take heed of his findings. “To our knowledge, our study provides the first evidence that U.S. blacks have a higher risk of SJS/TEN as ULD adverse events than U.S. Caucasians,” says Dr. Choi.
Information on racial and ethnic descent “can be used immediately for risk stratification to reduce adverse events,” he emphasizes.
Deborah Levenson is a writer and editor based in College Park, Md.
References
- Lu N, Rai SK, Terkeltaub R, Kim SC, Menendez ME, Choi HK. Racial disparities in the risk of Stevens-Johnson Syndrome and toxic epidermal necrolysis as urate-lowering drug adverse events in the United States. Semin Arthritis Rheum. 2016 Mar 31. pii: S0049-0172(16)30004-X. doi: 10.1016/j.semarthrit.2016.03.014. [Epub ahead of print]
- Khanna D, Fitzgerald JD, Khanna PP, Bae S, et al. 2012 American College of Rheumatology guidelines for management of gout. Part 1: Systematic nonpharmacologic and pharmacologic therapeutic approaches to hyperuricemia. Arthritis Care Res (Hoboken). 2012 Oct;64(10):1431–1446.
- Yang CY, Chen CH, Deng ST, et al. Allopurinol use and risk of fatal hypersensitivity reactions: A nationwide population-based study in Taiwan. JAMA Intern Med. 2015 Sep;175(9):1550–1557.
