Allopurinol okay on the kidneys in patients with gout

By Megan Brooks

NEW YORK (Reuters Health) - Allopurinol does not increase the risk of chronic kidney disease in patients with gout, according to a study presented today during a plenary session at the American College of Rheumatology annual meeting in Washington, D.C.

Gout is the most common inflammatory arthritis worldwide, but its management "remains suboptimal," study investigator Dr. Tuhina Neogi of Boston University School of Medicine told Reuters Health.

One aspect of suboptimal care of gout, Dr. Neogi explained by email, is the reduction in dose or discontinuation of allopurinol in patients who have kidney dysfunction "out of concern that allopurinol may be worsening kidney function. That then leads to poorer control of their gout. We therefore undertook this study to assess whether people with newly diagnosed gout who are starting allopurinol are at increased risk for developing chronic kidney disease stage 3 or higher."

Using an electronic health record database from the UK, the researchers identified 13,727 patients initiating allopurinol and an equal number of propensity score-matched patients who did not use the drug. Patients with chronic kidney disease stage 3 or higher were excluded.

Over an average follow-up of four years, 1,401 allopurinol initiators and 1,319 non-initiators developed CKD >/= stage 3.

Use of allopurinol was not associated with an increased risk of developing CKD >/= stage 3, compared with non-use, with an adjusted hazard ratio (HR) of 1.05 (95% CI 0.98 to 1.14). The adjusted HR remained unchanged in a sensitivity analysis.

"Chronic kidney disease stage 3 or higher occurs in about 20% of people with gout," Dr. Neogi said. "Yet, there hasn't been any direct evidence that allopurinol contributes to worsening kidney function. In addition, there are some emerging data that allopurinol may potentially improve kidney function among people who have kidney dysfunction. Although the majority of people with gout start out with normal kidney function, there are no data regarding the effects of allopurinol in contributing to renal dysfunction in such individuals."

The main message from this study, Dr. Neogi said, "is that for patients with gout who are starting allopurinol, there does not appear to be any adverse effect on kidney function due to allopurinol. Thus, if a patient with gout starts to have worsening kidney function, clinicians should not automatically stop allopurinol or reduce its dose because it is unlikely that the kidney dysfunction is due to allopurinol. And further, such an action will contribute to worsened control of their gout. Other factors that may be contributing to kidney dysfunction should be evaluated and addressed."

The study was supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases. The authors have disclosed no conflicts of interest.

SOURCE: https://bit.ly/2fPFpL5

American College of Rheumatology Annual Meeting 2016.