M.K. Reinders

A randomised controlled trial on the efficacy and tolerability with dose escalation of allopurinol 300–600 mg/day versus benzbromarone 100–200 mg/day in patients with gout

Objectives: To compare the efficacy and tolerability of allopurinol 300–600 mg/day versus benzbromarone 100–200 mg/day used to attain a target serum urate concentration (sUr) ⩽0.30 mmol/l (5 mg/dl). Methods: A randomised, controlled, open-label, multicentre trial in gout patients with renal function defined as a calculated creatinine clearance ⩾50 ml/min. Patients were treated with 300 mg allopurinol or 100 mg benzbromarone once a day (stage 1). If sUr ⩽0.30 mmol/l was not attained after 2 months, the dose was doubled to allopurinol 300 mg twice a day or benzbromarone 200 mg once a day (stage 2). The primary end point was treatment success in either of the two stages, defined as clinical tolerability and attainment of biochemical target sUr. Results: Sixty-five patients were enrolled in stage 1; 36 received allopurinol and 29 received benzbromarone. Fifty-five patients (85%) were analysed at stage 1: the success rates were 8/31 (26%) and 13/25 (52%), respectively, and the difference was −0.26 (95% CI from −0.486 to −0.005), p = 0.049. At stage 2, the success rates were 21/27 (78%) and 18/23 (78%), respectively, and the difference was −0.005 (95% CI from −0.223 to 0.220), p = 1.00. Two patients stopped receiving allopurinol and three stopped receiving benzbromarone because of adverse drug reactions. Conclusions: Increasing the allopurinol dose from 300 to 600 mg/day and the benzbromarone dose from 100 to 200 mg/day according to the target sUr produced significantly higher success rates (both 78% successful in attaining sUr ⩽0.30 mmol/l). No significant differences in treatment success between benzbromarone and allopurinol were found after dose escalation. Trial registration number: ISRCTN49563848).

Efficacy and tolerability of urate-lowering drugs in gout: a randomised controlled trial of benzbromarone versus probenecid after failure of allopurinol

Objectives: To investigate the efficacy and tolerability of allopurinol as the first-choice antihyperuricaemic treatment for gout, and compare the efficacy and tolerability of benzbromarone and probenecid as second-choice treatment. Methods: Prospective, multicentre, open-label, two-stage randomised controlled trial in gout patients with normal renal function. Enrolled patients were given 300 mg allopurinol for 2 months (stage 1). Those patients who could not tolerate allopurinol or who did not attain the target serum urate concentration (sUr) ⩽0.30 mmol/l (5.0 mg/dl), which was defined as successful, were randomised to benzbromarone 200 mg/day or probenecid 2 g/day for another 2 months (stage 2). Results: 96 patients were enrolled in stage 1. 82 patients (85%) were eligible for the analysis at the end of stage 1: there was a mean (SD) decrease in sUr concentration of 35 (11)% from baseline; 20 patients (24%) attained target sUr ⩽0.30 mmol/l; and 9 patients (11%) stopped allopurinol because of adverse drug reactions. 62 patients were enrolled in stage 2. 27 patients received benzbromarone (3 patients not eligible for analysis) and 35 received probenecid (4 patients not eligible for analysis). Treatment with benzbromarone was successful in 22/24 patients (92%) and with probenecid in 20/31 patients (65%) (p = 0.03 compared with benzbromarone). Compared with baseline values, there was a mean (SD) decrease of sUr concentration of 64 (9)% with benzbromarone and 50 (7)% with probenecid (p<0.001). Conclusion: This study showed that allopurinol 300 mg/day has a poor efficacy and tolerability profile when used to attain a biochemical predefined target level of sUr ⩽0.30 mmol/l, following 2 months of treatment. In stage 2, benzbromarone 200 mg/day was more effective and better tolerated than probenecid 2 g/day. Trial registration number: ISRCTN21473387.

Rasburicase treatment in severe tophaceous gout: a novel therapeutic option

We recently encountered a destructive case of tophaceous gout in a 57-year-old patient. Despite perfect therapy compliance, the patient failed in the conventional urate-lowering treatment, accounting for the ongoing urate retention and accumulation with progressive tophaceous bulky disease. Application of an experimental scheme of uricolytical therapy on this patient was able to reduce bulky disease significantly. In modern medicine, potent urate-debulking medication with urate oxidase (uricase) derivatives is at our disposal, and it is a challenge for rheumatologists to install the right strategy including innovative approaches with potent uricolytic therapy on the right patient at the right time.

Management of hyperuricemia in gout: focus on febuxostat

Gout is the most common inflammatory arthritis in an elderly population, and can be diagnosed with absolute certainty by polarization microscopy. However, diagnosis may be challenging because atypical presentations are more common in the elderly. Management of hyperuricemia in the elderly with gout requires special consideration because of co-medication, contra-indications, and risk of adverse reactions. Urate-lowering agents include allopurinol and uricosuric agents. These also must be used sensibly in the elderly, especially when renal function impairment is present. However, if used at the lowest dose that maintains the serum urate level below 5.0 to 6.0 mg/dL (0.30 to 0.36 mmol/L), the excess urate in the body will eventually be eliminated, acute flares will no longer occur, and tophi will resolve. Febuxostat, a new xanthine oxidase inhibitor, is welcomed, as few alternatives for allopurinol are available. Its pharmacokinetics and pharmacodynamics are not significantly altered in patients with moderate renal function or hepatic impairment. Its antihyperuricemic efficacy at 80 to 120 mg/day is better than “standard dosage” allopurinol (300 mg/day). Long-term safety data and efficacy data on tophus diminishment and reduction of gout flares have recently become available. Febuxostat may provide an important option in patients unable to use allopurinol, or refractory to allopurinol.

New advances in the treatment of gout: review of pegloticase.

Treatment-failure gout (TFG) affects approximately 50,000 patients or about 1% of the overall population of patients with gout in the United States of America. The severity of TFG is manifested by frequent acute attacks of disabling arthritis, chronic deforming joint disease, destructive masses of urate crystals (tophi), progressive physical disability, and poor health-related quality of life. Pegloticase (Krystexxa®; Savient Pharmaceuticals, Inc), a novel PEGylated urate oxidase (uricase) enzyme, has been resubmitted for US Food and Drug Administration approval. In a 6-month, placebo-controlled clinical trial, 8 mg of pegloticase for every 2 weeks induced a lytic decrease of serum urate (sUr) concentrations, leading to dissolution of tophi in 40% of patients at final visit. However, 58% were nonresponders to the defined target sUr of 0.36 mmol/L (80% were nonresponders during months 3 and 6), possibly due to anti-body formation. Also, 26%–31% experienced infusion reactions (IRs) and 77% suffered from gout flares. Although long-term data are awaited, an anti-inflammatory strategy, eg, based on glucocorticosteroids, is needed to prevent pegloticase antibody formation leading to IRs and diminished or shortened efficacy, and might also prevent gout flares. According to the current clinical data, pegloticase might have an important role as a (bridging) treatment in sUr-responsive patients for tophi clearance in severe chronic refractory gout.