Benzbromarone may reduce the risk of developing chronic kidney disease (CKD) among adults with asymptomatic hyperuricemia, new study findings suggest.

Using the 2003 to 2015 National Health Insurance Research Database in Taiwan, investigators propensity score matched 9107 benzbromarone users to 4554 allopurinol users by age, sex, and comorbidities. All patients had asymptomatic hyperuricemia, defined as the use of urate-lowering drugs without history of gout flares. Patients were free of gouty disorders and CKD at baseline. The cohort had a mean age of 56 years; 71% were male.

The benzbromarone group had a lower incidence of newly diagnosed CKD compared with the allopurinol group (1.18 vs 1.99 per 100 person-years).

Older age, male sex, and pre-existing diabetes and hypertension were each significantly associated with higher risk of CKD.

A Cox proportional hazards regression analysis showed that the benzbromarone group had a significant 41% lower risk of CKD diagnosis compared with the allopurinol group, Chiu-Shong Liu, MD, China Medical University in Taichung, Taiwan, and colleagues reported in the European Journal of Internal Medicine. Regardless of the cumulative defined daily drug dose, benzbromarone appeared more protective than allopurinol.

Benzbromarone may better reduce serum uric acid levels compared with allopurinol, according to Dr Liu’s team. The drug is an inhibitor of urate transporter 1 (URAT1) in the proximal tubule. The investigators could not evaluate serum uric acid levels, serum creatinine levels, albuminuria, or estimated glomerular filtration rate before or after drug use, which is a study limitation.

Patients with renal impairment or urolithiasis should avoid using benzbromarone, the investigators noted. The drug has been taken off the market in many countries due to the potential for hepatotoxicity.

Dr Liu’s team pointed out that in Taiwan urate-lowering treatment is considered when patients have high serum uric acid levels. These include individuals with serum uric acid levels of 9 mg/dL or more with comorbidities but no evidence of gouty arthritis, gouty tophi, or urolithiasis and those with serum uric acid levels of 10 mg/dL or more and no comorbidities. CKD risk might be higher for these patients.

“If the above approach is how physicians prescribe the urate-lowering drugs for persons included in our study, then the study findings might only apply to persons who have quite high serum level of uric acid,” Dr Liu and colleagues stated.

Reference

Lai SW, Liao KF, Kuo YH, Hwang BF, Liu CS. Comparison of benzbromarone and allopurinol on the risk of chronic kidney disease in people with asymptomatic hyperuricemia. Eur J Intern Med. Published online April 29, 2023. doi:10.1016/j.ejim.2023.04.025