Febuxostat dose requirement according to renal function in patients who achieve target serum urate levels: A retrospective cohort study

OBJECTIVES

To determine the febuxostat dose requirement according to renal function in patients who achieve target serum urate (SU) levels.

METHODS

Of 3153 gout patients who underwent febuxostat treatment, 873 patients with an initial SU level>6mg/dL were included and categorized by the estimated glomerular filtration rate: normal, chronic kidney disease (CKD) stage 3, and stages 4-5. Ninety-five patients with insufficient follow-up were further excluded. The dose of febuxostat in patients who achieved the SU target (< 6mg/dL) was defined as the average daily dosage at the time of SU target achievement.

RESULTS

The cohort of 778 gout patients had a median age of 52.0 years (IQR, 41.0-63.0) and comprised 711 (91.4%) men. The mean SU at febuxostat initiation was higher in the CKD 4-5 (9.6 [± 3.1] mg/dL) than in the other groups (CKD 3, 8.7 [± 1.7]; normal, 8.4 [± 1.7]; P<0.001). Patients achieved target SU at a median of 4.0 (1.9-9.6) months and in those who achieved target SU, the dose of febuxostat at the time of SU target achievement was significantly lower in the CKD 4-5 group (50.0 [± 16.5] mg) than in the other groups (vs. CKD stage 3, 60.0 [± 19.5] mg; P<0.01, vs. normal, 60.0 [± 19.8] mg; P<0.01). Furthermore, CKD stage 4-5 had a negative correlation with the febuxostat dose requirement (Beta: -2.334, P<0.05).

CONCLUSION

Among patients who achieved SU target, those with severely decreased renal function (CKD 4-5) required a lower febuxostat dose to achieve the target SU level compared to patients with normal or mild renal impairment.

Epidemiology and treatment-related concerns of gout and hyperuricemia in Korean

Gout is the most common form of inflammatory arthritis that affects mainly middle-aged men, and there is clear evidence of an association between hyperuricemia and the risk for gout. Increasing prevalence of gout and hyperuricemia has been reported in many countries. The prevalence of gout and hyperuricemia are constantly increasing in Korea with the patients at risk for developing a variety of comorbidities. Although there have been studies on the association between gout or serum uric acid level and several neurodegenerative diseases, cancer, and cardiovascular mortality, the causal relationship between gout and these comorbidities are still unclear. The associations of substantial economic burden with hyperuricemia, gout attack, and suboptimal treatment are well known. Gout is a disease that requires lifelong management including lifestyle modification. However, gout is poorly managed worldwide although effective urate-lowering drugs exist. In this review, we addressed epidemiological studies and treatment-related problems in the Korean population with gout or hyperuricemia to obtain the best clinical outcomes and reduce their medical burden.

Pharmacotherapy for gout

Background: Gout is a common disease that is mainly caused by hyperuricemia. Although it is relatively easy to treat, adherence to drug treatment and the rate at which treatment targets are met is low.Current Concepts: For the treatment of acute gout attack, colchicine, nonsteroidal anti-inflammatory drugs, and glucocorticoids can be used alone or in combination depending on the severity of symptoms. To prevent gout attacks, patients are started on colchicine prior to or concurrent with treatment with uric acid–lowering drugs. The treatment is maintained until serum uric acid levels have returned to normal, and the patient has had no acute attacks for three to six months. Ultimately, the symptoms of gout are controlled in the long term by treating the patient’s hyperuricemia. For this purpose, allopurinol, febuxostat, and benzbromarone are used, and the side effects and contraindications for each drug should be checked. The goal for the treatment of chronic gout is to maintain a serum uric acid concentration below 6.0 mg/dL.Discussion and Conclusion: Patients visit the emergency departments of hospitals for sudden gout attacks. However, gout is a chronic disease that requires the lifelong use of uric acid–lowering agents. Therefore, it is necessary to educate patients on a serum urate-based treat-to-target approach.