LAUSR

Background Use of diuretics is a common bystander in patients with gout, and it has been reported to impair response to allopurinol [1,2] and likely lead to treatment failure and refractoriness. However, after the introduction of new urate-lowering therapies (ULT) and treat-to-target strategies, whether this inconvenient effect of diuretics persists has not received critical attention to date. Objectives To analyze the impact of the diuretic therapy on the response to ULT in patients with gout. Methods Retrospective analysis of an inception cohort in patients with crystal-proven gout (Jan2014-Nov2016). Patients were classified according to the use of diuretics (loop and/or thiazide) at baseline. The primary outcome variables were the reduction of serum uric acid (SUA) levels and the achievement of different objectives of SUA (6, 5, and 4mg/dL); as secondary outcome variable the maximum dose of ULT was registered, as well as other clinical, analytical, and ULT-related data. A comparative analysis was performed according to the use of diuretics, using Student's t and chi-2 tests. Also, the analysis was stratified according to the ULT used. Results The inception cohort included 225 patients with an average age of 65 years (SD 14.1), being 86.2% of them men. The median duration of gout at inclusion was 4 years (p25–75 1–10) and 21.3% presented tophi. At baseline, the median (p25–75) SUA and estimated glomerular filtration rate were 8.2 mg/dL (7.2–9.2) and 75.9 mL/min (27.2–88.3), respectively. A total of 98 patients (43.6%) were on diuretics mainly for hypertension (64.7%), heart failure (9.4%), and renal failure (5.9%). Follow-up data was available from 209 patients (92.9%), with a median 9 months of follow-up (4–14). ULT used was allopurinol in 172 patients (82.6%), febuxostat in 34 (16.5%), and benzbromarone in only 2 cases (0.9%). Regarding the baseline characteristics, patients on diuretics were older, had higher rates of females, hypertension, diabetes, and cardiovascular disease, and showed higher SUA and lower glomerular filtration rate. The table shows the outcomes comparison according to diuretic treatment, globally and stratified by type of ULT (excluding the two cases of benzbromarone). Except for a lower achievement of SUA<5 in the allopurinol subgroup, no significant differences were found either globally or by type of ULT. Outcome variable Diuretic therapy p No Yes Whole sample (N=209) N=117 n=92 – SUA reduction (mg/dL), mean (SD) 3.2 (2.1) 3.7 (2.5) 0.196 – SUA<6 (%) 80.0% 75.9% 0.458 – SUA<5 (%) 61.0% 50.6% 0.126 – SUA<4 (%) 31.4% 28.9% 0.575 Allopurinol (n=158) N=92 N=66 – SUA reduction (mg/dL), mean (SD) 3.1 (1.9) 3.2 (2.0) 0.813 – SUA<6 (%) 80.6% 74.2% 0.337 – SUA<5 (%) 60.2% 43.9% 0.043 – SUA<4 (%) 28.0% 21.2% 0.334 – Maximum dose (mg/day), mean (SD) 316.5 (126.9) 278.6 (121.8) 0.053 Febuxostat (n=33) N=14 N=19 – SUA reduction (mg/dL), mean (SD) 3.7 (3.4) 5.6 (3.1) 0.147 – SUA<6 (%) 70.0% 82.4% 0.456 – SUA<5 (%) 70.0% 76.5% 0.711 – SUA<4 (%) 60.0% 58.8% 0.952 – Maximum dose (mg/day), mean (SD) 80.0 (16.3) 80.0 (25.3) 0.348 Conclusions Despite its high rate, diuretics currently seem to not have a significant impact on the achievement of the different objectives of treatment of patients with gout. References Rheumatology; 55:1172. Br J Clin Pharmacol; 81:277. Disclosure of Interest None declared