Previous Dosage of Allopurinol Is a Strong Determinant of Febuxostat Efficacy

The Effect of Decrease in Serum Urate for the Risk of Gout Flares During Urate-Lowering Therapy Initiation Among Chinese Male Gout Patients: A Prospective Cohort Study

Purpose

Higher baseline serum urate or higher initial urate-lowering medication dose increased risk of gout flares during urate-lowering therapy (ULT) initiation. The decrease in serum urate may play a crucial role in this process. Therefore, we aim to explore the relationship between decrease in serum urate and the risk of gout flares during ULT initiation.

Patients and Methods

A 12-week prospective cohort study of Chinese male gout patients was conducted at Shandong Provincial Clinical Research Center for Immune Diseases and Gout in China. Patients were grouped by baseline serum urate (7-7.9 mg/dL, 8-8.9 mg/dL and ≥9 mg/dL). All patients received febuxostat 20 mg daily during weeks 0-4, then escalated to 40mg during weeks 4-12 if serum urate >6mg/dL. The main outcomes were the number of gout flares and the decrease in serum urate. Poisson regression was performed.

Results

A total of 282 participants were enrolled, of whom 260 completed (84, 87 and 89 in each group) from March 2021 to December 2021. A 44.2% of all participants experienced at least one gout flare. In the multivariate Poisson regression 1, Δ serum urate 0-12 weeks (IRR 1.184, 95% CI, 1.062-1.320; P=0.002), the number of gout flares before treatment 1 year (1.017, 1.010-1.024; P<0.001) and tophus (1.580, 1.023-2.440; P=0.039) were independently associated with the number of gout flares. While in the multivariate Poisson regression 2, baseline serum urate (1.256, 1.050-1.503; P=0.013) and the number of gout flares before treatment 1 year (1.014, 1.007-1.022; P<0.001) were independently associated with the number of gout flares, Δ serum urate 0-12 weeks (1.055, 0.923-1.207; P=0.433) was no longer a risk factor.

Conclusion

ULT-induced gout flares depend on the degree of decrease in serum urate, which is affected by baseline serum urate. Higher baseline serum urate and greater decrease in serum urate lead to higher risk of gout flares.

Efficacy of febuxostat versus allopurinol and the predictors of achieving target serum urate in a cohort of Thai people with gout

OBJECTIVE

The objectives of our study were to compare the efficacy of febuxostat with allopurinol in Thai subjects with gout, as well as to determine the predictive factors of responsiveness to urate-lowering agents and to evaluate the safety of febuxostat in a real-world setting.

METHODS

The study was a retrospective cohort study; a total of 354 gout patients were recruited from February 2015 to November 2018. The patients were categorized according to prescription of allopurinol or febuxostat. Demographic data, comorbidities, concomitant medications, gout-related clinical parameters, and the laboratory results were collected. The serial serum urate (sUA) levels were recorded at the beginning of the treatment (baseline), and after treatment at 12 weeks, 18 weeks, and 27 weeks. The primary efficacy endpoint was the achievement of target urate of < 6 mg/dl in people taking febuxostat, compared with those taking allopurinol. The secondary endpoints were the predictive factors of achieving target urate level and adverse drug reactions in patients taking febuxostat. Multivariable regression analysis was used to determine factors associated with achieving target serum urate.

RESULTS

After the treatment, the febuxostat groups had significantly lower mean sUA compared with the allopurinol groups across all follow-up periods. The proportion of people who achieved target serum urate was also higher in the febuxostat groups compared with the allopurinol groups throughout the follow-up periods. The multivariable regression analysis showed that febuxostat 40 mg (OR = 10.96 (95% CI 4.32-27.80); p value < 0.001), febuxostat 80 mg (OR = 9.54 (95% CI 3.91-23.28), smoking (OR = 2.35 (95% CI 1.13-4.91); p value = 0.023), and low baseline serum urate (OR = 0.62 (95% CI 0.52-0.74); p value < 0.001) were associated with the achievement of target serum urate. No adverse drug reaction from febuxostat was observed even among people with renal insufficiency.

CONCLUSION

In a Thai cohort, people receiving febuxostat are more likely to achieve target serum urate level, compared with people receiving allopurinol. Febuxostat (40 or 80 mg), smoking, and low baseline serum urate were associated with the achievement of target serum urate.

KEY POINTS

• Febuxostat showed superior urate-lowering efficacy compared with allopurinol in an Asian population. • In addition to febuxostat, lower baseline serum urate level and history of smoking were associated with achieving target serum urate in gout patients.

Pharmacological urate-lowering approaches in chronic kidney disease

Chronic kidney disease (CKD) has become a global public health issue and uric acid (UA) remains a major risk factor of CKD. As the main organ for the elimination of UA, kidney owned a group of urate transporters in tubular epithelium. Kidney disease hampered the UA excretion, and the accumulation of serum UA in return harmed the renal function. Commercially, there are three kinds of agents targeting at urate-lowering, xanthine oxidoreductase inhibitor which prevents the production of UA, uricosuric which increases the concentration of UA in urine thus decreasing serum UA level, and uricase which converts UA to allantoin resulting in the dramatic decrement of serum UA. Of note, in patients with CKD, administration of above-mentioned agents, alone or combined, needs special attention. New evidence is emerging for the efficacy of several urate-lowering drugs for the treatment of hyperuricemia in patients with CKD. Besides, loads of novel and promising drug candidates and phytochemicals are in the different phases of research and development. As of today, there is insufficient evidence to recommend the widespread use of UA-lowering therapy to prevent or slow down the progression of CKD. The review summarized the evidence and perspectives about the treatment of hyperuricemia with CKD for medicinal chemist and nephrologist.