Background: Accumulating evidences has suggested that hyperuricemia is associated with aggravation of chronic kidney disease (CKD). Treatment guidelines propose, the administration of a uric acid production inhibitor to achieve serum uric acid level below 6 mg /dL in CKD patients with hyperuricemia; however, the success rate is not satisfactory.
Case Series: Herein, we outlined our experience of the treatment of six patients with advanced CKD with the newly launched uric acid-lowering agent dotinurad, which inhibits the reabsorption of uric acid in the proximal tubule by blocking urate transporter 1 (URAT1). Dotinuradwas administered at a low dose of 0.5 mg per day for 24 weeks. The serum uric acid levels improved significantly in all patients (7.58 ± 0.47 mg / dL to 6.10 ± 0.29 mg / dL after 4 weeks, 6.16 ± 1.02 mg / dL after 12 weeks and 6.12 ± 1.08 mg / dL after 24 weeks). Further, the uric acid clearance / creatinine clearance ratio increased from 5.0 ± 1.8 % to 7.3 ± 2.6 % after 4 weeks. Urinary pH was significantly increased, achieving “alkalization” after 4 weeks (5.8 ± 0.9 to 6.6 ± 0.9). Renal function deterioration and new-onset gout attacks did not appear.
Conclusion: A small dose of dotinurad administered for 24 weeks improved CKD symptoms in all patients, resulting in an increase in uric acid excretion into the urine. Interestingly, the urine became alkalized, indicating that this agent may also inhibit the production of urinary stones.