Duration and dose of allopurinol needed to attain the serum urate target in gout

To examine, in patients with gout using escalating urate-lowering therapy (ULT), the treatment duration and allopurinol dose required to attain the serum urate (SU) target (< 360 μmol/L; < 6 mg/dL).

We studied patients in the NOR-Gout prospective cohort with a recent gout flare and increased SU (> 360 μmol/L). Patients escalated allopurinol dosage until reaching the SU treatment target of <360 µmol/L, switching, if needed, to febuxostat.

Of 211 patients, 95.2% were male; mean ± sd age was 56.7 ± 13.7 years, disease duration 8.1 years, 16.6% had clinical tophi, and 12.8% used allopurinol at cohort entry. Mean SU (μmol/L) was reduced from 500 at baseline to 312 at 1 year and 325 at 2 years. Target SU was attained at least once during year 1 by 197 patients (93.4%). Median time to attaining the treatment target was 2 months (mean 2.9 months), and median allopurinol dose was 200 mg (mean 243 mg). Eighty per cent of patients reached the treatment target by 3 months. Patients with SU >480 μmol/L at baseline needed a median of 3 months to attain target SU versus 2 months for patients with SU <480 μmol/L (log-rank p < 0.001). A switch to febuxostat was seen in 12.4% at year 1 and 15.1% at year 2.

Treat-to-target ULT using allopurinol leads to attainment of the SU target within 2-3 months at low doses for most patients. Very few patients did not achieve the treatment target at least once during year 1.

ACTRN12618001372279.