Lessons to be learned from real life data from 98 gout patients using benzbromarone

Abstract

Aim: This study aims to analyze the efficacy and safety of benzbromarone as uricosuric, in a real-life clinical setting of a retrospective hospital-based gout cohort. Methods: Data from gout patients were retrieved from the digital hospital dossiers. Demographics, clinical variables, and laboratory parameters were collected at baseline and 6 months. Efficacy was measured by reaching a serum uric acid (sUA) target < 0.30 mmol/L at 6 months, and the fractional excretion of uric acid (FeUA) was used as a parameter with a potential predictor value. Results: Data from 98 gout patients were analyzed. Patients were 70 (± 12) years of age, and 90% were male. After 6 months of treatment, 68 out of 98 patients (69%) reached a sUA level < 0.30 mmol/L (5 mg/dL). In patients with a FeUA < 4.5%, so-called low excretors, the FeUA increase was most impressive from 3.2% (± 1.0%) to 12.1% (± 6.9%) after 6 months of benzbromarone treatment (mean increase +8.9% [95% confidence interval (CI): +6.5 to +11.5%], P < 0.001). In non-low excretors, FeUA was on average 7.3% (± 5.1%) and increased to 9.7% (± 6.1%): a mean +2.1% change (95% CI: –2.2 to +6.6%). The increase differed insignificantly in low versus non-low excretors: P > 0.05. Four patients stopped benzbromarone treatment because of a progressive decline in renal function, a condition that was already present before benzbromarone was initiated. Remarkably 38% of patients still using benzbromarone after 3.8 (± 3.4) years of treatment. Conclusions: Using the uricosuric benzbromarone in real-life gout patients proved effectivity in lowering sUA levels within 6 months by increasing FeUA significantly. Particularly low excretors benefit from benzbromarone treatment manipulating this mode of action. Determining FeUA in gout patients may further help to find the patient profile benefiting the most from benzbromarone treatment.