Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018099 (gout)
 5,192 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The manifestations of gout can be abolished permanently by lifelong urate-lowering therapy maintaining serum urate levels under 360 mmol/l, as this ensures dissolution of pathogenic crystals of monosodium urate monohydrate. Benzbromarone has been withdrawn from the market, leaving allopurinol as the only urate-lowering drug readily available in France. Allopurinol may induce unacceptable side effects, and in patients with dose-limiting renal failure it may not be sufficiently effective. Because allopurinol can induce serious side effects when given concomitantly with purine antimetabolites, it is contraindicated in organ transplant recipients. In patients who cannot tolerate allopurinol, dietary treatment, discontinuation of diuretic agents, and use of losartan or fenofibrate to treat concomitant hypertension or dyslipidemia, respectively, may ensure adequate control of serum urate levels. Desensitization to allopurinol can be attempted in patients with mild cutaneous hypersensitivity reactions but is difficult to perform and rarely used. Uricosuric agents may be helpful in patients with normal or diminished urate excretion. Probenecid is available in France from hospital pharmacies, and benzbromarone can be prescribed via a time-limited authorization procedure. Rasburicase, an Aspergillus urate oxidase produced by genetic engineering, is indicated to prevent acute hyperuricemia induced by chemotherapy for hematological malignancies. Factors that limit the use of rasburicase include the absence of a marketing authorization, the need for parenteral administration, and the absence of validated treatment schedules. Patients with renal failure precluding the use of effective allopurinol dosages are good candidates for benzbromarone therapy. Organ transplant recipients can be given benzbromarone, within the current restrictions to its use; alternatively, mycophenolate mofetil can be substituted for calcineurin inhibitors, which elevate serum urate levels, or for azathioprine, which contraindicates the use of allopurinol.
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PMID:Current management of gout in patients unresponsive or allergic to allopurinol. 1558 27

Allopurinol, a commonly prescribed medication for gout and hyperuricemia, is a frequent cause of severe cutaneous adverse reactions (SCAR), which include the drug hypersensitivity syndrome, Stevens-Johnson syndrome, and toxic epidermal necrolysis. The adverse events are unpredictable and carry significant morbidity and mortality. To identify genetic markers for allopurinol-SCAR, we carried out a case-control association study. We enrolled 51 patients with allopurinol-SCAR and 228 control individuals (135 allopurinol-tolerant subjects and 93 healthy subjects from the general population), and genotyped for 823 SNPs in genes related to drug metabolism and immune response. The initial screen revealed strong association between allopurinol-SCAR and SNPs in the MHC region, including BAT3 (encoding HLA-B associated transcript 3), MSH5 (mutS homolog 5), and MICB (MHC class I polypeptide-related sequence B) (P < 10(-7)). We then determined the alleles of HLA loci A, B, C, and DRB1. The HLA-B*5801 allele was present in all (100%) 51 patients with allopurinol-SCAR, but only in 20 (15%) of 135 tolerant patients [odds ratio 580.3 (95% confidence interval, 34.4-9780.9); corrected P value = 4.7 x 10(-24)] and in 19 (20%) of 93 of healthy subjects [393.51 (23.23-6665.26); corrected P value = 8.1 x 10(-18)]. HLA alleles A*3303, Cw*0302, and DRB1*0301 were in linkage disequilibrium and formed an extended haplotype with HLA-B*5801. Our results indicated that allopurinol-SCAR is strongly associated with a genetic predisposition in Han Chinese. In particular, HLA-B*5801 allele is an important genetic risk factor for this life-threatening condition.
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PMID:HLA-B*5801 allele as a genetic marker for severe cutaneous adverse reactions caused by allopurinol. 1574 17

Allopurinol is frequently used for the treatment of hyperuricemia and gout. Sometimes, a life-threatening reaction develops, as is illustrated by the following case report. We describe a 60-year-old male patient who was treated with allopurinol because of asymptomatic hyperuricemia, and he was presented with fever, skin rash, eosinophilia, worsening renal function and vanishing bile duct syndrome. In this report, we discussed vanishing bile duct syndrome as a serious side effect of allopurinol, and we briefly reviewed the etiology, prevention, and treatment modalities for vanishing bile duct syndrome.
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PMID:[A case of vanishing bile duct syndrome associated with hypersensitivity to allopurinol]. 1578 88

Hyperuricemia is present in approximately 5% of the population, the vast majority of whom are asymptomatic and at no clinical risk. Complications, including renal calculi, uric acid nephropathy and gout, occur in a small proportion of patients. Allopurinol, an analog of hypoxanthine, has been widely used in clinical practice for over 30 years for the treatment of hyperuricemia and gout. Two percent of patients taking this medication develop a mild exanthema. A syndrome characterized by exfoliative dermatitis, hepatitis, interstitial nephritis and eosinophilia has been described previously. Termed allopurinol hypersensitivity syndrome, its etiology is related to the accumulation of one of the allopurinol metabolites, oxypurinol; clearance of oxypurinol is decreased in the setting of renal insufficiency and the use of thiazide diuretics. The term DRESS syndrome (Drug Rash with Eosinophilia and Systemic Symptoms) was recently introduced to describe a disorder associated with various drugs or viral infections and characterized by similar features. The pathophysiology of allopurinol-induced hypersensitivity, clinical presentation and treatment are reviewed.
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PMID:Allopurinol-induced DRESS syndrome. 1625 49

Hyperuricaemia occurs in 5-84% and gout in 1.7-28% of recipients of solid organ transplants. Gout may be severe and crippling, and may hinder the improved quality of life gained through organ transplantation. Risk factors for gout in the general population include hyperuricaemia, obesity, weight gain, hypertension and diuretic use. In transplant recipients, therapy with ciclosporin (cyclosporin) is an additional risk factor. Hyperuricaemia is recognised as an independent risk factor for cardiovascular disease; however, whether anti-hyperuricaemic therapy reduces cardiovascular events remains to be determined. Dietary advice is important in the management of gout and patients should be educated to partake in a low-calorie diet with moderate carbohydrate restriction and increased proportional intake of protein and unsaturated fat. While gout is curable, its pharmacological management in transplant recipients is complicated by the risk of adverse effects and potentially severe interactions between immunosuppressive and hypouricaemic drugs. NSAIDs, colchicine and corticosteroids may be used to treat acute gouty attacks. NSAIDs have effects on renal haemodynamics, and must be used with caution and with close monitoring of renal function. Colchicine myotoxicty is of particular concern in transplant recipients with renal impairment or when used in combination with ciclosporin. Long-term urate-lowering therapy is required to promote dissolution of uric acid crystals, thereby preventing recurrent attacks of gout. Allopurinol should be used with caution because of its interaction with azathioprine, which results in bone marrow suppression. Substitution of mycophenylate mofetil for azathioprine avoids this interaction. Uricosuric agents, such as probenecid, are ineffective in patients with renal impairment. The exception is benzbromarone, which is effective in those with a creatinine clearance >25 mL/min. Benzbromarone is indicated in allopurinol-intolerant patients with renal failure, solid organ transplant or tophaceous/polyarticular gout. Monitoring for hepatotoxicty is essential for patients taking benzbromarone. Physicians should carefully consider therapeutic options for the management of hypertension and hyperlipidaemia, which are common in transplant recipients. While loop and thiazide diuretics increase serum urate, amlodipine and losartan have the same antihypertensive effect with the additional benefit of lowering serum urate. Atorvastatin, but not simvastatin, may lower uric acid, and while fenofibrate may reduce serum urate it has been associated with a decline in renal function. Gout in solid organ transplantation is an increasing and challenging clinical problem; it impacts adversely on patients' quality of life. Recognition and, if possible, alleviation of risk factors, prompt treatment of acute attacks and early introduction of hypouricaemic therapy with careful monitoring are the keys to successful management.
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PMID:Gout in solid organ transplantation: a challenging clinical problem. 1639 75

The prototypical xanthine oxidase (XO) inhibitor allopurinol, has been the cornerstone of the clinical management of gout and conditions associated with hyperuricemia for several decades. More recent data indicate that XO also plays an important role in various forms of ischemic and other types of tissue and vascular injuries, inflammatory diseases, and chronic heart failure. Allopurinol and its active metabolite oxypurinol showed considerable promise in the treatment of these conditions both in experimental animals and in small-scale human clinical trials. Although some of the beneficial effects of these compounds may be unrelated to the inhibition of the XO, the encouraging findings rekindled significant interest in the development of additional, novel series of XO inhibitors for various therapeutic indications. Here we present a critical overview of the effects of XO inhibitors in various pathophysiological conditions and also review the various emerging therapeutic strategies offered by this approach.
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PMID:Therapeutic effects of xanthine oxidase inhibitors: renaissance half a century after the discovery of allopurinol. 1650 84

An acute attack of gouty arthritis is one of the most painful experiences reported throughout medical history. Therefore it is paramount to initiate appropriate therapy quickly in order to terminate the acute phase. This goal can be achieved with non-steroidal anti-inflammatory agents, colchicine, or corticosteroid-based therapies. Rarely, because of contraindications to these agents, only symptomatic treatment can be given until the attack subsides. The next step is to lower the serum urate level below the limit of solubility (i.e., below 40.8 mmol/L, or 6.8mg/dL) which reduces recurrences and begins to return the total body urate pool to normal. This equally important goal can be achieved by uricosuric agents or xanthine oxidase inhibitors, although the latter is generally favored. Allopurinol is the agent most commonly preferred because of its safety profile and ease of use, but there are known serious allergic reactions and untoward side effects that occasionally require discontinuation. Febuxostat, a xanthine oxidase inhibitor, and pegylated uricase are new agents under development and may be beneficial in these situations or when other comorbid conditions prevent the use of conventional treatments. Alcohol and dietary consumption are also related to hyperuricemia and acute gout. Recently beer, wine, and liquor were studied and the risk of gout varied according to the alcohol ingested. Furthermore, recent data sheds light on important dietary modifications that may help in the treatment of gout, and dispels certain beliefs about protein ingestion and the occurrence of acute gout. As we learn more about the associated conditions of hypertriglyceridemia, hypertension, and the metabolic syndrome, it may allow the tailoring of medical regimens that directly prevent or reduce recurrent attacks of gouty arthritis. There are specific approved treatments for these common comorbidities that have parallel effects of lowering serum urate levels. These recent findings may be especially important for treating refractory cases. While patient education remains a cornerstone to ensure compliance, other quality indicators for the management of this disease have been reported and should guide the clinician in the treatment of gout and result in improved care.
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PMID:Advances in the management of gout and hyperuricaemia. 1688 87

Allopurinol is used widely for the treatment of purine disorders such as gout, but efficacy and safety of allopurinol has not been analyzed systematically in an extensive series of patients with HPRT deficiency. From 1984 to 2004 we have diagnosed 30 patients with HPRT deficiency. Eighteen patients (12 with Lesch-Nyhan syndrome or complete HPRT deficiency, and 6 with partial HPRT deficiency) were treated with allopurinol (mean dose, 6.44 mg/Kg of weight per day) and followed-up for at least 12 months (mean follow-up 7,6 years per patient). Mean age at diagnosis was 7 years (range, 5 months to 35 years). Treatment with allopurinol was associated to a mean reduction of serum urate concentration of 50%, and was normalized in all patients. Mean urinary uric acid excretion was reduced by 75% from baseline values, and uric acid to creatinine ratio was close or under 1.0 in all patients. In contrast, hypoxanthine and xanthine urinary excretion rates increased by a mean of 6 and 10 times, respectively, compared to baseline levels. These modifications were similar in patients with complete or partial HPRT deficiency. In 2 patients xanthine stones were documented despite allopurinol dose adjustments to prevent markedly increased oxypurine excretion rates. Neurological manifestations did not appear to be influenced by allopurinol therapy. Allopurinol is a very efficacy and fairly safety drug for the treatment of uric acid overproduction in patients with complete and partial HPRT deficiency. Allopurinol was associated with xanthine lithiasis.
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PMID:Efficacy and safety of allopurinol in patients with the Lesch-Nyhan syndrome and partial hypoxanthine- phosphoribosyltransferase deficiency: a follow-up study of 18 Spanish patients. 1706 67

Since 1993 we have studied 5 Spanish families with familial nephropathy associated with hyperuricemia (FJHN). Among these families, 24 patients have been identified. All patients had some combination of hyperuricemia, gout, renal insufficiency, arterial hypertension, and reduced kidney size. The clinical presentation in the different families and in the members of the same family was heterogeneous. Allopurinol treatment did not appear to influence renal disease. From a clinical perspective, this syndrome is a distinctive interstitial nephropathy, inherited as an autosomal dominant trait, that progresses to renal failure and is not halted nor prevented by allopurinol therapy. In 2003, genetic linkage analysis in 3 of the 5 families showed linkage of FJHN to 16p 11.2. One family was not analyzed and one family did not show linkage to this region confirming the genetic heterogeneity of this syndrome. A mutation in UMOD gene was found in these 3 families as the cause of the FJHN. The mutations cluster in exon 4 and exon 5 and were point mutation that results in an amino acid change in the uromodulin or Tamm Horsfall protein. This fact allowed in 2004, the presymptomatic genetic diagnosis of an 8-years-old boy belonging to one of these 3 Spanish families. We conclude that in families with a history of renal failure and/or gout in which FJHN is suspected, UMOD mutation screening may enable a definite diagnosis. When a mutation is found, family members can be tested for a UMOD mutation and pre-symptomatic diagnosis may allow counseling to prevent or halt the progression to renal insufficiency.
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PMID:Familial nephropathy associated with hyperuricemia in Spain: our experience with 3 families harbouring a UMOD mutation. 1706 10

In 2003, the uricosuric drug benzbromarone was withdrawn from the market. The first alternative drug of choice was the xanthine oxidase inhibitor allopurinol. The purpose was to (1) investigate the efficacy of allopurinol (standard dosage) compared with previous treatment with benzbromarone; and (2) investigate the combination therapy allopurinol-probenecid as an effective alternative treatment compared with previous benzbromarone treatment. A prospective, open study was carried out in a cohort of 51 gout patients who discontinued benzbromarone therapy because of market withdrawal. Patients were given 200-300 mg allopurinol (stage 1). When allopurinol failed to attain the target serum urate (sUr) levels <or=0.30 mmol/l, probenecid 1,000 mg/day was added (stage 2). Treatment with benzbromarone monotherapy (range: 100-200 mg/day; mean 138 mg/day) resulted in 92% of patients reaching target levels sUr <or= 0.30 mmol/l with a decrease of 61[11]% compared to baseline. In stage 1, 32 patients completed treatment with allopurinol monotherapy (range 200-300 mg/day; mean 256 mg/day), which resulted in 25% of patients attaining sUr target levels. Decrease in sUr levels was 36[11]%, which was significantly less compared to treatment with benzbromarone (p < 0.001). In stage 2, 14 patients received allopurinol-probenecid combination therapy, which resulted in 86% of patients attaining target sUr levels (after failure on allopurinol monotherapy), which was comparable to previous treatment with benzbromarone (p = 0.81). Decrease in sUr levels was 53[9]% (CI 95%: 48-58%), which was a non-significant difference compared to previous treatment with benzbromarone (p = 0.23). Benzbromarone is a very effective antihyperuricemic drug with 91% success in attainment of target sUr levels <or=0.30 mmol/l. Allopurinol 200-300 mg/day was shown to be a less potent alternative for most selected patients to attain target sUr levels (13% success). In patients failing on allopurinol monotherapy, the addition of probenecid proves to be an effective treatment strategy for attaining sUr target levels (86% success).
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PMID:Biochemical effectiveness of allopurinol and allopurinol-probenecid in previously benzbromarone-treated gout patients. 1730 59


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