Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P47989 (xanthine oxidase)
 8,633 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gout may be a primary or a secondary disorder. In both types of gout, overproduction or underexcretion of uric acid, or a combination of these abnormalities, may be the underlying mechanism. Controversy exists over the need for treatment of asymptomatic hyperuricemia. Treatment of tophi requires use of both uricosurics and allopurinol. A xanthine oxidase inhibitor is the drug of choice for patients with uric acid stones and for those with renal insufficiency.
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PMID:Hyperuricemia and gout: an update. 689 39

APRT deficiency is an enzyme disorder which is inherited as an autosomal recessive trait. The use of adenine in purine metabolism is disturbed and it accumulates in the body, where it is oxidised by xanthine oxidase to poorly insoluble 2, 8-dihydroxyadenine (DHA). The dihydroxyadenine forms stones which cause recurrent urolithiasis, frequent episodes of urinary tract infection or interstitial nephritis, and finally renal insufficiency in some cases. We report a case of APRT deficiency discovered by urine examination. The patient was a 33-year-old man who had never had any episodes of urolithiasis. He was admitted to our hospital because of pseudoarthrosis of his left arm caused by a traffic accident. His urinalysis revealed no proteinuria nor hematuria, but disclosed numerous round brown crystals in the sediment. These crystals had the characteristics of 2, 8-DHA. The enzyme activity of APRT in his blood was completely deficient. He was diagnosed as an APRT* QO homozygote. In addition, diagnostic imaging revealed that his right kidney was poorly hypoplastic and the pelvis of his left kidney was extra-renal. The renal function was slightly disturbed. In Japan 6 cases of 2, 8-DHA urolithiasis associated with hypoplastic kidney had been reported by 1989. Theoretically, the incidence of hypoplastic kidney is around 20% of all 2, 8-DHA urolithiasis cases. We suspect a genetic correlation between hypoplastic kidney and APRT deficiency. This patient was treated with Allopurinol, which inhibits the process of xanthine oxidation, after which crystals were no longer detected in his urine.
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PMID:[A case of adenine phosphoribosyltransferase (APRT) deficiency discovered by urine examination]. 781 52

Xanthine calculi were found in a 7-month-old male Cavalier King Charles spaniel with urethral obstruction and renal insufficiency. Because the only two other reported cases of naturally occurring xanthine urolithiasis concerned a Cavalier King Charles and a King Charles spaniel the urine of the littermates and parents of the patient were also examined for xanthinuria. Semi-quantitative analysis revealed high urine concentrations of hypoxanthine and xanthine in the patient and his female littermate. Quantitative analysis by high-pressure liquid chromatography (HPLC) of the urine samples from the family of this Cavalier King Charles spaniel and nine control dogs revealed that hypoxanthine and xanthine excretion was 30 and 60 times higher in the affected patient and the female littermate than in the others dogs. The pattern of xanthinuria, which is caused by a deficiency of the enzyme xanthine oxidase, in the relation diagram of this family of Cavalier King Charles Spaniels was consistent with an autosomal recessive mode of inheritance.
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PMID:Xanthinuria in a family of Cavalier King Charles spaniels. 941 15

There are three stages in the management of gout: (i) treating the acute attack; (ii) lowering excess stores of uric acid to prevent flares of gouty arthritis and to prevent tissue deposition of urate; and (iii) providing prophylaxis to prevent acute flares. It is important to distinguish between therapy to reduce acute inflammation in acute gout and therapy to manage hyperuricaemia in patients with chronic gouty arthritis. During the acute gouty attack nonpharmacological treatments such as topical ice and rest of the inflamed joint are useful. NSAIDs are the preferred treatment in acute gout. The most important determinant of therapeutic success is not which NSAID is chosen, but rather how soon NSAID therapy is initiated. Other treatments include oral and intravenous colchicine, intra-articular and systemic corticosteroids, and intramuscular corticotropin. Optimal treatment of chronic gout requires long-standing reduction in serum uric acid. The urate-lowering drugs used to treat chronic gout are the uricosuric drugs, the uricostatic drugs, which are xanthine oxidase inhibitors, and the uricolytic drugs. Xanthine oxidase inhibitors such as allopurinol, oxipurinol and febuxastat should be used as first-line treatment in patients with renal calculi, renal insufficiency, concomitant diuretic therapy and ciclosporin (cyclosporine) therapy, and urate overproduction. Uricosuric drugs include probenecid, benzbromarone, micronised fenofibrate and losartan. They are the urate-lowering drugs of choice in allopurinol-allergic patients and underexcretors with normal renal function and no history of urolithiasis. The use of recombinant urate oxidase in patients with chronic gout is limited by the need for parenteral administration, the potential antigenicity and production of anti-urate oxidase antibodies, and declining efficacy. The effectiveness of colchicine prophylaxis as an isolated therapy is still to be confirmed by placebo-controlled trials. Another issue is prophylaxis with NSAIDs. There are no comparative studies with colchicine.
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PMID:Management of acute and chronic gouty arthritis: present state-of-the-art. 1548 99

Febuxostat is a non-purine, selective inhibitor of xanthine oxidase being developed for the management of hyperuricaemia in patients with gout. With febuxostat 10-120 mg, the pharmacokinetics are linear. No dose adjustment appears to be necessary in those with renal insufficiency or mild-to-moderate hepatic impairment. Febuxostat 10-120 mg/day rapidly and sustainably reduces serum uric acid by 25-70% in uric acid underexcretors and overproducers. Prophylaxis with colchicine or a non-steroidal anti-inflammatory drug can mitigate the gout-flare risk from the rapid urate lowering after febuxostat initiation. Febuxostat is well tolerated, the majority of treatment-related adverse events are transient and mild-to-moderate in severity. Febuxostat can broaden the therapeutic options for urate-lowering therapy in those with gout.
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PMID:Febuxostat: a non-purine, selective inhibitor of xanthine oxidase for the management of hyperuricaemia in patients with gout. 1602 78

The prevalence of gout has increased markedly in the United States in the past two decades, and new treatments for hyperuricemia are being developed. Recent molecular identification of urate transporter-1 (URAT1) as the central mediator of renal urate reabsorption has provided novel understanding of the pathogenesis of hyperuricemia, and the target site for current and possibly future primary uricosuric agents. Recent studies have also highlighted uricosuric effects of several drugs (losartan, atorvastatin, fenofibrate) that are prescribed for primary indications other than hyperuricemia. The niche of these agents in current management of hyperuricemia is discussed. We also review the ongoing development of recombinant uricase preparations and of novel xanthine oxidase inhibitors exemplified by febuxostat. These agents should provide novel options for patients with chronic, refractory gout and hyperuricemia, particularly in association with allopurinol hypersensitivity and renal insufficiency.
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PMID:New developments in clinically relevant mechanisms and treatment of hyperuricemia. 1690 Oct 81

Febuxostat is a novel non-purine selective inhibitor of xanthine oxidase being developed for the management of hyperuricaemia in patients with gout. To critically review the clinical trial data, safety profile, pharmacology, and role of febuxostat for the treatment of hyperuricemia and gout. A review of the literatures on febuxostat was performed. All available human studies describing the pharmacology of febuxostat were included; including pharmacodynamics, efficacy, and safety of febuxostat. Available studies, patents and abstracts were identified through PubMed (1990-December 2006), Delphion, Cochrane Databases, and the American College of Rheumatology and European League Against Rheumatism Web sites. Key search terms were febuxostat, TMX-67, and TEI-6720. Febuxostat has been used at a dose of 80 to 120 mg for the management of hyperuricemia in gout. The drug is mainly metabolized by the liver and therefore mild-moderate renal impairment does not appear to impede its effect. However, given the limited long-term liver function safety data, failure of a large percentage of patients taking febuxostat to achieve the primary end point of serum urate levels less than 6.0 mg/dL, and higher drop out rate in the Febuxostat group in the clinical trials, the exact role of febuxostat as a urate-lowering therapy remains uncertain. Febuxostat is a promising alternative to allopurinol for the treatment of gout and hyperuricemia. The optimal length of colchicines prophylactic therapy for chronic gout, clinical significance of abnormal liver function tests results during therapy, and safety in patients with moderate or severe hepatic and renal insufficiency warrant further investigation. A post-market surveillance is also needed to address the safety issue of long-term febuxostat treatment.
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PMID:Febuxostat: a novel non-purine selective inhibitor of xanthine oxidase for the treatment of hyperuricemia in gout. 1907 68

Crystals in tissues lead the innate immune system to the same kind of acute response seen with pathogens. Via activation of the inflammasome, interleukin-1 (IL-1) is released, which upregulates mediators such as cyclooxygenase, tumor necrosis factor, and IL-8 and induces an acute granulocytic inflammation. Therefore, in addition to nonsteroidal anti-inflammatory drugs (NSAIDs), steroids, and colchicine, IL-1 blockers appear to be effective. Large clinical trials have already been initiated. Such an approach could constitute a valuable alternative for patients with contraindications or insufficient response to NSAIDs. After the attack has subsided, control of uric acid metabolism is central. At least several of the responsible urate transporters have been unraveled, which could lead to more focused therapy in the future. At present, diet and blockade of uric acid synthesis remain the main pillars of therapy. The new xanthine oxidase inhibitor febuxostat constitutes a novel option for patients with renal insufficiency or intolerance to allopurinol.
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PMID:[Crystal-induced activation of the inflammasome: gout and pseudogout]. 1983 18

Gout is a common, painful, and often debilitating rheumatologic disorder that remains one of the few arthritic conditions that can be diagnosed with certainty and cured with appropriate therapy. Allopurinol is the most frequently prescribed agent for gout in the United States. Unfortunately, most patients treated with allopurinol do not achieve target serum uric acid (sUA) levels, possibly due to a perceived intolerability to allopurinol in doses above 300 mg and the need for reduced doses in patients with renal insufficiency. Febuxostat, an orally administered, nonpurine inhibitor of xanthine oxidase, was recently approved by the U.S. Food and Drug administration for chronic management of hyperuricemia in patients with gout. Patients treated with febuxostat achieve rapid and substantial reductions in sUA levels. Compared with allopurinol-treated patients, patients receiving febuxostat 80 mg/day were more likely to achieve sUA concentrations less than 6 mg/dl. In long-term studies (up to 5 yrs), febuxostat demonstrated sustained reductions in sUA levels, nearly complete elimination of gout flares, and a frequency of adverse effects comparable to allopurinol. The most commonly reported adverse effects were liver function abnormalities, rash, nausea, and arthralgias. The recommended starting dose of febuxostat is 40 mg/day, which may be increased to 80 mg/day after 2 weeks if patients do not achieve sUA levels less than 6 mg/dl. Dosage adjustment in mild-to-moderate renal insufficiency is unnecessary; however, data are lacking on the safety of febuxostat in patients with severe renal impairment. Although more costly than allopurinol, febuxostat appears to be an acceptable alternative for the treatment of gout and hyperuricemia, and may be advantageous in patients with renal impairment, intolerance to allopurinol, or the inability to attain sUA levels less than 6 mg/dl despite adequate therapy with available agents.
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PMID:Urate-lowering therapy for gout: focus on febuxostat. 2050 48

The prevalence of gout in the western countries is 1-2%. The disease has become more common during the last two decades, and the same time its clinical picture has changed. The disease is often polyarticular, the patients are older than before and they have more often associated cardiovascular diseases and renal insufficiency. Effective treatment of acute gout is nonsteroidal anti-inflammatory drugs with intra-articular or systematic corticosteroids. The goal for the treatment of intermittent and chronic gout is to maintain serum urate concentration velow 360 micromol/l by diet and by antihyperuricemic meditation, primarly allopurinole and probenecid. Febuxostat is a new xanthine oxidase inhibitor, which will be available for the treatment of refractory gout in the near future. Special attention should be paid on detecting and treating cardiovascular diseases and their risk factors in patients with gout.
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PMID:[The clinical picture of gout is changing]. 2061 51


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