Table 2 Efficacy of allopurinol as first-line serum urate (sUr)-lowering treatment (stage 1) and benzbromarone versus probenecid as second-line treatment (stage 2)
Stage 1Stage 2Probenecid 2 g/dayp Value*
Allopurinol 300 mg/dayBenzbromarone 200 mg/day
Treatment success resultsn = 82n = 24n = 31
    Treatment goal reached
        sUr ⩽0.30 mmol/l, n (%)20 (24)22 (92)20 (65)0.03
            95% CI16–3573–9945–81
    Treatment goal not reached
    Withdrawn due to ADR, n (%)9 (11)1 (4)8 (26)
    sUr 0.31–0.36 mmol/l, n (%)26 (32)0 (0)1 (3)
    sUr >0.36 mmol/l, n (%)27 (33)1 (4)2 (6)
Urate resultsn = 73n = 23n = 23
    sUr reached (mmol/l), mean (SD)0.34 (0.06)0.19 (0.07)0.27 (0.05)<0.001
        Range0.23–0.460.12–0.460.20–0.40
    ΔsUr from baseline (%), mean (SD)−35 (11)−64 (9)−50 (7)<0.001
    uUr (mmol/day), mean (SD)2.2 (1.2)5.3 (1.9)4.7 (1.7)NS
        Range0.8–6.62.6–9.30.5–8.1
    UrCl (ml/min/1.73 m2), mean (SD)3.6 (1.8)17.7 (7.2)10.1 (4.5)<0.001
        Range1.3–7.36.7–33.41.2–23.2
Drug serum concentrations
    Serum oxipurinol (mg/l), mean (SD)13.2 (7.1)
        Range2.5–39.2
  • *Comparison of stage 2 groups.

  • ADR, adverse drug reaction; NS, non-significant (p>0.05); sUr, serum urate; UrCl, urate clearance; uUr, urate excreted in urine.