Starting dose is a risk factor for allopurinol hypersensitivity syndrome: A proposed safe starting dose of allopurinol

Easing the way to achieving target serum urate in people with gout: protocol for a non-inferiority randomised strategy trial using an allopurinol dosing model in Aotearoa/New Zealand (the Easy-Allo Study)

INTRODUCTION

Gout is one of the most common forms of arthritis worldwide. Gout is particularly prevalent in Aotearoa/New Zealand and is estimated to affect 13.1% of Māori men, 22.9% of Pacific men and 7.4% of New Zealand European men. Effective long-term treatment requires lowering serum urate to <0.36 mmol/L. Allopurinol is the most commonly used urate-lowering medication worldwide. Despite its efficacy and safety, the allopurinol dose escalation treat-to-target serum urate strategy is difficult to implement and there are important inequities in allopurinol prescribing in Aotearoa. The escalation strategy is labour intensive, time consuming and costly for people with gout and the healthcare system. An easy and effective way to dose-escalate allopurinol is required, especially as gout disproportionately affects working-age Māori men and Pacific men, who frequently do not receive optimal care.

METHODS AND ANALYSIS

A 12-month non-inferiority randomised controlled trial in people with gout who have a serum urate ≥ 0.36 mmol/l will be undertaken. 380 participants recruited from primary and secondary care will be randomised to one of the two allopurinol dosing strategies: intensive nurse-led treat-to-target serum urate dosing (intensive treat-to-target) or protocol-driven dose escalation based on dose predicted by an allopurinol dosing model (Easy-Allo). The primary endpoint will be the proportion of participants who achieve target serum urate (<0.36 mmol/L) at 12 months.

ETHICS AND DISSEMINATION

The New Zealand Northern B Health and Disability Ethics Committee approved the study (2022 FULL 13478). Results will be disseminated in peer-reviewed journals and to participants.

TRIAL REGISTRATION NUMBER

ACTRN12622001279718p.

[Gout, beyond the joint: How should we treat it?]

Gout is a disease caused by the chronic deposition of monosodium urate crystals. Its clinical presentation as an acute, self-limiting arthritis and the belief that it is a banal, self-inflicted disease have led to its poor management. Despite advances in the knowledge of the disease and the simplicity of its management, no more than 30% of patients are well treated. In Spain, the prevalence of gout is 2.5% and its incidence is increasing. In the following article we will review the pathogenesis of gout and hyperuricaemia, highlighting the greater weight of genetics and renal function over diet. We will look at the consequences of crystal deposition. Gout, in addition to its joint presentation and renal involvement, has been shown to be an independent cardiovascular risk factor. Hypouricemic therapy is the most important treatment, as it is the one that dissolves the crystals and cures the disease. This requires the sustained achievement of uricemia levels below 6mg/dl. We will also review preventive and flares treatment, as well as the role of patient education in terms of both lifestyle and dietary habits and adherence to pharmacological treatment.

Efficacy and Safety of Allopurinol and Febuxostat in Patients With Gout and CKD: Subgroup Analysis of the STOP Gout Trial

RATIONALE & OBJECTIVE

We conducted a prespecified examination of the efficacy and safety of allopurinol and febuxostat administered using a treat-to-target strategy in trial participants with chronic kidney disease (CKD).

STUDY DESIGN

Prespecified sub cohort analysis of a randomized controlled trial.

SETTING

& Participants: A sub study of the STOP Gout trial in participants with CKD. CKD was defined as an eGFR 30-59 mL/min/1.73 m2 at baseline.

EXPOSURE

Trial participants with CKD and gout and serum urate (sUA) concentration ≥6.8 mg/dL were randomized 1:1 to receive allopurinol or febuxostat. Urate lowering therapy (ULT) was titrated during weeks 0-24 to achieve a goal sUA of <6.0 mg/dl (<5.0 mg/dl with tophi) (Phase 1) and maintained during weeks 25-48 (Phase 2). Gout flare was assessed between weeks 49-72 (Phase 3).

OUTCOME

Gout flare between weeks 49-72 (Phase 3) was the primary outcome. Secondary outcomes included sUA goal achievement and ULT dosing at end of Phase 2, and serious adverse events (SAEs).

ANALYTICAL APPROACH

Outcomes between treatment groups were compared using logistic regression models for binary outcomes, and Poisson regression for flare rates. Multivariable models were subsequently used, adjusting for factors identified to be imbalanced by treatment arm.

RESULTS

351 of 940 participants (37.3%) had CKD; 277 were assessed for the primary outcome. Fewer patients randomized to allopurinol had a flare during phase 3 (32% vs 45%; p=0.02) despite similar attainment of sUA goal (79% vs. 81%; p=0.6) by the end of Phase 2. Acute kidney injury (AKI) was more common in participants with stage 3 CKD randomized to allopurinol compared to febuxostat.

LIMITATIONS

Limited power to assess infrequent safety events, largely male, older population.

CONCLUSIONS

Allopurinol and febuxostat are similarly efficacious and well-tolerated in the treatment of gout in people with CKD when used in a treat-to-target regimen.

Comparative Risk of Gout Flares When Initiating or Escalating Various Urate-Lowering Therapy: A Systematic Review With Network Meta-Analysis

OBJECTIVE

We systematically examined comparative gout flare risk after initiation or escalation of different urate-lowering therapies (ULTs), comparative flare risk with and without concomitant flare prophylaxis, adverse event rates associated with flare prophylaxis, and optimal duration of flare prophylaxis.

METHODS

We searched the Medline, Embase, Web of Science, and Cochrane databases and clinical trial registries from inception to November 2021 for trials investigating adults with gout initiating or escalating ULT. We performed random effects network meta-analyses and calculated risk ratios (RRs) between treatments. Bias was assessed using the revised Cochrane risk-of-bias tool.

RESULTS

We identified 3,775 records, of which 29 publications (27 trials) were included. When compared to placebo plus prophylaxis, the RR of flares ranged from 1.08 (95% confidence interval [CI] 0.87-1.33) for febuxostat 40 mg plus prophylaxis to RR 2.65 [95% CI 1.58-4.45] for febuxostat 80 mg plus lesinurad 400 mg plus prophylaxis. Compared to ULT alone, the RR of flares was lower for ULT plus rilonacept 160 mg (RR 0.35 [95% CI 0.25-0.50]), ULT plus rilonacept 80 mg (RR 0.43 [95% CI 0.31-0.60]) and ULT plus colchicine (RR 0.50 [95% CI 0.35-0.72]). There was limited evidence for other flare prophylaxis and on prophylaxis harms and optimal duration. Primarily because of missing outcome data and bias in the selection of reported results, 71.4% and 63.4% of studies were assessed as high risk of bias for flares and adverse events, respectively.

CONCLUSION

The RR of flares when introducing ULT varies depending on ULT drug and dosing strategies. There were limited data on ULT escalation. Flare prophylaxis with colchicine and rilonacept reduces flare incidence. More research is required on the harms and optimal duration of prophylaxis.

Gout and its management

Gout is a common and treatable chronic disease of monosodium urate crystal deposition. It is experienced as extremely painful episodes of joint inflammation that impact all aspects of the person's life. This Clinical Perspectives article provides an update on gout diagnosis, medications and strategies to improve the quality of gout care.

The development and evaluation of dose-prediction tools for allopurinol therapy (Easy-Allo tools)

AIMS

Dose escalation at the initiation of allopurinol therapy can be protracted and resource intensive. Tools to predict the allopurinol doses required to achieve target serum urate concentrations would facilitate the implementation of more efficient dose-escalation strategies. The aim of this research was to develop and externally evaluate allopurinol dosing tools, one for use when the pre-urate-lowering therapy serum urate is known (Easy-Allo1) and one for when it is not known (Easy-Allo2).

METHODS

A revised population pharmacokinetic-pharmacodynamic model was developed using data from 653 people with gout. Maintenance doses to achieve the serum urate target of <0.36 mmol L-1 in >80% of individuals were simulated and evaluated against external data. The predicted and observed allopurinol doses were compared using the mean prediction error (MPE) and root mean square error (RMSE). The proportion of Easy-Allo predicted doses within 100 mg of the observed was quantified.

RESULTS

Allopurinol doses were predicted by total body weight, baseline urate, ethnicity and creatinine clearance. Easy-Allo1 produced unbiased and suitably precise dose predictions (MPE 2 mg day-1 95% confidence interval [CI] -13-17, RMSE 91%, 90% within 100 mg of the observed dose). Easy-Allo2 was positively biased by about 70 mg day-1 and slightly less precise (MPE 70 mg day-1 95% CI 52-88, RMSE 131%, 71% within 100 mg of the observed dose).

CONCLUSIONS

The Easy-Allo tools provide a guide to the allopurinol maintenance dose requirement to achieve the serum urate target of <0.36 mmol L-1 and will aid in the development of novel dose-escalation strategies for allopurinol therapy.

Targeting Neutrophil Extracellular Traps in Gouty Arthritis: Insights into Pathogenesis and Therapeutic Potential

Gouty arthritis (GA) is an immune-mediated disorder characterized by severe inflammation due to the deposition of monosodium urate (MSU) crystals in the joints. The pathophysiological mechanisms of GA are not yet fully understood, and therefore, the identification of effective therapeutic targets is of paramount importance. Neutrophil extracellular traps (NETs), an intricate structure of DNA scaffold, encompassing myeloperoxidase, histones, and elastases - have gained significant attention as a prospective therapeutic target for gouty arthritis, due to their innate antimicrobial and immunomodulatory properties. Hence, exploring the therapeutic potential of NETs in gouty arthritis remains an enticing avenue for further investigation. During the process of gouty arthritis, the formation of NETs triggers the release of inflammatory cytokines, thereby contributing to the inflammatory response, while MSU crystals and cytokines are sequestered and degraded by the aggregation of NETs. Here, we provide a concise summary of the inflammatory processes underlying the initiation and resolution of gouty arthritis mediated by NETs. Furthermore, this review presents an overview of the current pharmacological approaches for treating gouty arthritis and summarizes the potential of natural and synthetic product-based inhibitors that target NET formation as novel therapeutic options, alongside elucidating the intrinsic challenges of these inhibitors in NETs research. Lastly, the limitations of HL-60 cell as a suitable substitute of neutrophils in NETs research are summarized and discussed. Series of recommendations are provided, strategically oriented towards guiding future investigations to effectively address these concerns. These findings will contribute to an enhanced comprehension of the interplay between NETs and GA, facilitating the proposition of innovative therapeutic strategies and novel approaches for the management of GA.

The Association between High-Dose Allopurinol and Erythropoietin Hyporesponsiveness in Advanced Chronic Kidney Disease: JOINT-KD Study

INTRODUCTION

The aim of the study was to explore the association between urate-lowering agents and reduced response to erythropoietin-stimulating agents in patients suffering from chronic kidney disease G5.

METHODS

We conducted a cross-sectional, multicenter study in Japan between April and June 2013, enrolling patients aged 20 years or older with an estimated glomerular filtration rate of ≤15 mL/min/1.73 m2. Exclusion criteria encompassed patients with a history of hemodialysis, peritoneal dialysis, or organ transplantation. The patients were categorized into four groups based on the use of urate-lowering drugs: high-dose allopurinol (>50 mg/day), low-dose allopurinol (≤50 mg/day), febuxostat, and no-treatment groups. We used a multivariable logistic regression model, adjusted for covariates, to determine the odds ratio (OR) for erythropoietin hyporesponsiveness, defined by an erythropoietin resistance index (ERI) of ≥10, associated with urate-lowering drugs.

RESULTS

A total of 542 patients were included in the analysis, with 105, 36, 165, and 236 patients in the high-dose allopurinol, low-dose allopurinol, febuxostat, and no-treatment groups, respectively. The median and quartiles of ERIs were 6.3 (0, 12.2), 3.8 (0, 11.2), 3.4 (0, 9.8), and 4.8 (0, 11.2) in the high-dose allopurinol, low-dose allopurinol, febuxostat, and no-treatment groups, respectively. The multivariate regression model showed a statistically significant association between the high-dose allopurinol group and erythropoietin hyporesponsiveness, compared to the no-treatment group (OR = 1.98, 95% confidence interval: 1.10-3.57).

CONCLUSIONS

Our study suggests that the use of high-dose allopurinol exceeding the optimal dose may lead to hyporesponsiveness to erythropoiesis-stimulating agents.

Is colchicine prophylaxis required with start-low go-slow allopurinol dose escalation in gout? A non-inferiority randomised double-blind placebo-controlled trial

OBJECTIVES

To determine whether placebo is non-inferior to low-dose colchicine for reducing gout flares during the first 6 months of allopurinol using the 'start-low go-slow' dose approach.

METHODS

A 12-month double-blind, placebo-controlled non-inferiority trial was undertaken. Adults with at least one gout flare in the preceding 6 months, fulfilling the American College of Rheumatology (ACR) recommendations for starting urate-lowering therapy and serum urate ≥0.36 mmol/L were recruited. Participants were randomised 1:1 to colchicine 0.5 mg daily or placebo for the first 6 months. All participants commenced allopurinol, increasing monthly to achieve target urate <0.36 mmol/L. The primary efficacy outcome was the mean number of gout flares/month between 0 and 6 months, with a prespecified non-inferiority margin of 0.12 gout flares/month. The primary safety outcome was adverse events over the first 6 months.

RESULTS

Two hundred participants were randomised. The mean (95% CI) number of gout flares/month between baseline and month 6 was 0.61 (0.47 to 0.74) in the placebo group compared with 0.35 (0.22 to 0.49) in the colchicine group, mean difference 0.25 (0.07 to 0.44), non-inferiority p=0.92. There was no difference in the mean number of gout flares/month between randomised groups over the 12-month period (p=0.68). There were 11 serious adverse events in 7 participants receiving colchicine and 3 in 2 receiving placebo.

CONCLUSIONS

Placebo is not non-inferior to colchicine in prevention of gout flares in the first 6 months of starting allopurinol using the 'start-low go-slow' strategy. After stopping colchicine, gout flares rise with no difference in the mean number of gout flares/month between groups over a 12-month period.

TRIAL REGISTRATION NUMBER

ACTRN 12618001179224.

Impact of pharmacist-led collaborative gout clinic on timely achievement of serum uric acid goals

Background

The concept of a pharmacist-led collaborative gout clinic is relatively new in Singapore.

Objective

This study examined the impact of this pilot shared care model on providing dose titration of urate lowering therapy, gout education and patient support to achieve target serum uric acid (sUA) levels.

Method

A retrospective pre-post study was undertaken to compare outcomes in patients who were started on either allopurinol or febuxostat in the 24 months prior to (Group A: Pre implementation) or 33 months following launch of the collaborative gout clinic (Group B: Post implementation). The collaborative gout clinic comprises of a clinical pharmacist under the supervision of a rheumatologist.

Results

Of 98 eligible subjects enrolled in our study, there were 50 patients (all prescribed allopurinol) for Group A and 48 patients for Group B (allopurinol n = 29, febuxostat n = 19). Among patients who achieved target sUA level of 360 μmol/L or less at 1 year of drug initiation with use of allopurinol, the median [interquartile range, IQR] time taken to attain target sUA was shorter in Group B than Group A (111 [82–308] days vs. 293 [265–414] days, p = 0.016). As compared to Group A, Group B had lesser patients experiencing gout flare (41.3% vs. 70.0%, p = 0.018) and more patients achieving target sUA (75.9% vs. 22.0%, p < 0.001). Mean ± [standard deviation, SD] daily allopurinol dose to achieve target sUA levels was 276 mg ± [138 mg].

Conclusion

Our results demonstrate the use of a pharmacist-led collaborative gout clinic may help to achieve better clinical outcomes in gout management.

Population pharmacokinetics, pharmacodynamics and pharmacogenetics modelling of oxypurinol in Hmong adults with gout and/or hyperuricemia

AIMS

The aim of this study was to quantify identifiable sources of variability, including key pharmacogenetic variants in oxypurinol pharmacokinetics and their pharmacodynamic effect on serum urate (SU).

METHODS

Hmong participants (n = 34) received 100 mg allopurinol twice daily for 7 days followed by 150 mg allopurinol twice daily for 7 days. A sequential population pharmacokinetic pharmacodynamics (PKPD) analysis with non-linear mixed effects modelling was performed. Allopurinol maintenance dose to achieve target SU was simulated based on the final PKPD model.

RESULTS

A one-compartment model with first-order absorption and elimination best described the oxypurinol concentration-time data. Inhibition of SU by oxypurinol was described with a direct inhibitory Emax model using steady-state oxypurinol concentrations. Fat-free body mass, estimated creatinine clearance and SLC22A12 rs505802 genotype (0.32 per T allele, 95% CI 0.13, 0.55) were found to predict differences in oxypurinol clearance. Oxypurinol concentration required to inhibit 50% of xanthine dehydrogenase activity was affected by PDZK1 rs12129861 genotype (-0.27 per A allele, 95% CI -0.38, -0.13). Most individuals with both PDZK1 rs12129861 AA and SLC22A12 rs505802 CC genotypes achieve target SU (with at least 75% success rate) with allopurinol below the maximum dose, regardless of renal function and body mass. In contrast, individuals with both PDZK1 rs12129861 GG and SLC22A12 rs505802 TT genotypes would require more than the maximum dose, thus requiring selection of alternative medications.

CONCLUSIONS

The proposed allopurinol dosing guide uses individuals' fat-free mass, renal function and SLC22A12 rs505802 and PDZK1 rs12129861 genotypes to achieve target SU.

Management of Patients with Gout and Kidney Disease: A Review of Available Therapies and Common Missteps

Gout, a common form of inflammatory arthritis, is characterized by deposition of monosodium urate crystals in articular and periarticular tissues. Repeated flares of gout cause joint damage as well as significant health care utilization and decreased quality of life. Patients with CKD have a higher prevalence of gout. Treating Patients with CKD and gout is challenging because of the lack of quality data to guide management in this specific population. This often leads to suboptimal treatment of patients with gout and impaired renal function because concerns regarding the efficacy and safety of available gout therapies in this population often result in significant interphysician variability in treatment regimens and dosages. Acute gout flares are treated with various agents, including nonsteroidal anti-inflammatory drugs, colchicine, glucocorticoids, and-more recently-IL-1 inhibitors. These medications can also be used as prophylaxis if urate-lowering therapy (ULT) is initiated. While these drugs can be used in patients with gout and CKD, there are often factors that complicate treatment, such as the numerous medication interactions involving colchicine and the effect of glucocorticoids on common comorbidities, such as diabetes and hypertension. ULT is recommended to treat recurrent flares, tophaceous deposits, and patients with moderate-to-severe CKD with a serum urate goal of <6 mg/dl recommended to prevent flares. While many misconceptions exist around the risks of using urate-lowering agents in patients with CKD, there is some evidence that these medications can be used safely in Patients with renal impairment. Additional questions exist as to whether gout treatment is indicated for Patients on RRT. Furthermore, there are conflicting data on whether ULT can affect renal function and cardiovascular disease in patients. All of these factors contribute to the unique challenges physicians face when treating patients with gout and CKD.

The Hong Kong Society of Rheumatology consensus recommendations for the management of gout

Gout is one of the most common noncommunicable diseases in Hong Kong. Although effective treatment options are readily available, the management of gout in Hong Kong remains suboptimal. Like other countries, the treatment goal in Hong Kong usually focuses on relieving symptoms of gout but not treating the serum urate level to target. As a result, patients with gout continue to suffer from the debilitating arthritis, as well as the renal, metabolic, and cardiovascular complications associated with gout. The Hong Kong Society of Rheumatology spearheaded the development of these consensus recommendations through a Delphi exercise that involved rheumatologists, primary care physicians, and other specialists in Hong Kong. Recommendations on acute gout management, gout prophylaxis, treatment of hyperuricemia and its precautions, co-administration of non-gout medications with urate-lowering therapy, and lifestyle advice have been included. This paper serves as a reference guide to all healthcare providers who see patients who are at risk and are known to have this chronic but treatable condition.

Therapeutics in rheumatology and the kidney

The field of rheumatology has advanced significantly in recent years to provide rheumatologists with an extensive array of medications to combat rheumatic joint conditions. In contrast to an older era, when NSAIDs and other nephrotoxic agents were the mainstay of treatment, modern DMARDs vary considerably in their nephrotoxic potential and their use is not always precluded in populations with pre-existing chronic kidney disease (CKD). This review will explore in detail the safety and efficacy profiles of medications used to treat rheumatologic disease, specifically in the setting of CKD. Specifically, we discuss both traditional agents used, i.e. NSAIDs, CSs and conventional synthetic DMARDs, as well as novel biologic DMARDs and targeted synthetic DMARDs. Anti-gout prescribing in CKD is also reviewed. We aim to provide practical guidance to rheumatologists, nephrologists and general physicians when prescribing these medications in the setting of CKD.

The Singapore Experience With Uncontrolled Gout: Unmet Needs in the Management of Patients

Gout is the most common type of inflammatory arthritis, and its impact on cardiovascular health and quality of life is often underestimated. The prevalence and incidence of gout are increasing globally. Further, ischemic heart disease (IHD) and chronic kidney disease (CKD) are prevalent in gout patients. Some unmet needs for gout management include physicians' low initiation rate of urate-lowering therapy (ULT) and poor treatment adherence in patients with gout. There is also a lack of randomized controlled trials that establish safe doses of acute and long-term treatment for gout, particularly in patients with IHD and stage 4 CKD and above (including end-stage renal failure). Furthermore, there is also a lack of studies showing optimal serum uric acid (SUA) target and validated clinical outcome measures, including disease activity and remission criteria for gout tailored to treat-to-target approaches and the high cost of newer gout medications. The causal relationship between asymptomatic hyperuricemia or gout with comorbidities such as IHD and CKD has yet to be fully elucidated. There is a pressing need for collaborative international efforts to address the overall suboptimal management of gout.

A Drug-Drug Interaction Study of a Novel Selective Urate Reabsorption Inhibitor, SHR4640, and Xanthine Oxidase Inhibitor, Febuxostat, in Patients With Primary Hyperuricemia

SHR4640 is a novel, selective urate reabsorption inhibitor. As the mode of action of SHR4640 differs from that of a xanthine oxidase inhibitor, such as febuxostat, coadministration of these drugs may be a treatment option for patients with primary hyperuricemia. We assessed the potential drug-drug interaction between SHR4640 and febuxostat. In this single-center, open-label, randomized, drug-drug interaction study, subjects received 80 mg febuxostat or 10 mg SHR4640 alone daily in the first week, whereas during the second week a combination of SHR4640 and febuxostat was administered daily to all subjects. Plasma concentrations of SHR4640 and febuxostat were analyzed. We compared their pharmacokinetic and pharmacodynamic parameters and assessed both safety and tolerability. Compared with febuxostat alone, the geometric mean ratios (90%CIs) of the maximum concentration (C_max ) and the area under the plasma concentration-time curve over the dosing interval τ (AUC_0-τ ) for febuxostat after coadministration were 1.284 (1.016 to 1.621) and 0.984 (0.876 to 1.106), respectively. The geometric mean ratios (90%CIs) of C_max and AUC_0-τ for SHR4640 after coadministration compared with SHR4640 alone were 0.910 (0.839 to 0.988) and 0.929 (0.893 to 0.966), respectively. Febuxostat had no effect on SHR4640 pharmacokinetic parameters, as the 90%CIs of the geometric mean ratios were all within the range of 0.80 to 1.25. The coadministration of febuxostat and SHR4640 was well tolerated. The coadministration of SHR4640 with febuxostat was not associated with any clinically relevant pharmacokinetic drug interactions. SHR4640 combined with febuxostat had a synergistic effect on reducing uric acid in the pharmacodynamics, with the AUC decreasing from 7440 to 3170 h μmol/L compared with febuxostat alone and from 5730 to 2960 h μmol/L compared with SHR4640 alone.

Initiation Dose of Allopurinol and the Risk of Severe Cutaneous Reactions in Older Adults With CKD: A Population-Based Cohort Study

RATIONALE & OBJECTIVE

Allopurinol should be started at lower doses in patients with chronic kidney disease (CKD) to avoid adverse effects. We examined the risk of severe cutaneous reactions in older adults with CKD who were newly prescribed allopurinol at varied doses.

STUDY DESIGN

Population-based cohort study using linked health care databases.

SETTING & PARTICIPANTS

Patients in Ontario, Canada (2008-2019) aged ≥66 years, with an estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73 m², and who were new users of allopurinol.

EXPOSURE

A new prescription for allopurinol >100 mg/d versus a dose ≤100 mg/d.

OUTCOME

The primary outcome was a hospital visit with a severe cutaneous reaction within 180 days of starting allopurinol. Secondary outcomes included all-cause hospitalization and all-cause mortality.

ANALYTICAL APPROACH

The exposure and referent groups were balanced on indicators of baseline health using inverse probability of treatment weighting on the propensity score. Weighted risk ratios (RR) were obtained using modified Poisson regression and weighted risk differences (RD) using binomial regression.

RESULTS

Of 47,315 patients (median age, 76 years; median eGFR, 45 mL/min/1.73 m²), 55% started allopurinol at >100 mg/d. Starting allopurinol at >100 versus ≤100 mg/d was associated with an increased risk of a severe cutaneous reaction: number of events (weighted), 103 of 25,802 (0.40%) versus 46 of 25,816 (0.18%), respectively (weighted RR, 2.25 [95% CI, 1.50-3.37]; weighted RD, 0.22% [95% CI, 0.12%-0.32%]. Starting allopurinol at >100 versus ≤100 mg/d was associated with an increased risk of all-cause hospitalization but not with all-cause mortality.

LIMITATIONS

This study was underpowered to detect risk differences in the association of allopurinol dose with outcomes across eGFR categories (ie, 45-59, 30-44, and <30 mL/min/1.73 m²).

CONCLUSIONS

Older patients with CKD who started allopurinol at >100 mg/d versus ≤100 mg/d were twice as likely to visit a hospital with a severe cutaneous reaction in the next 180 days.

The effect of allopurinol on cardiovascular outcomes in patients with type 2 diabetes: a systematic review

BACKGROUND

Cardiovascular disease (CVD) remains the main cause of death in patients with type 2 diabetes (T2D). Although hyperuricemia has been associated with multiple CV complications, it is not officially recognized as a target parameter for CVD risk reduction.

AIM

To systematically review the literature in order to determine whether treating hyperuricemia with allopurinol in patients with T2D reduces CVD risk.

METHODS

A thorough literature search in the PubMed, CENTRAL, and EMBASE databases from inception to August 2022 was performed. After application of selection criteria, 6 appropriate studies were identified.

RESULTS

Detailed analysis of the data derived indicated that there is an association between allopurinol treatment and CV benefits, resulting in a reduced risk of CVD events and mortality rates. This association can be attributed mainly to the reduction of inflammation and oxidative burden, as well as to the improvement of glycemic and lipid profiles.

CONCLUSIONS

This systematic review provides evidence that allopurinol may reduce CVD risk in patients with T2D. Randomized, placebo-controlled trials should be performed in order to confirm these findings and identify specific subgroups of patients who will benefit most.

Considerations for Choosing First-Line Urate-Lowering Treatment in Older Patients with Comorbid Conditions

Gout is the most common inflammatory arthritis in adults. The prevalence of gout increases with age. Urate-lowering treatment (ULT) among older patients is often challenging in that patients frequently suffer insufficient effectiveness or adverse events due to comorbidities, concurrent medications, and altered pharmacokinetics. The large-scale randomized controlled trials (RCTs) directly investigating gout patients regarding cardiovascular (CV) safety have only recently been introduced; CARES and FAST compared the CV safety of the two xanthine oxidase inhibitors (XOis), febuxostat versus allopurinol, in patients with gout. Based on the CARES trial that showed CV concerns with febuxostat, the current international guidelines recommend allopurinol as first-line ULT in gout, while preserving other agents as a second-line treatment, despite a higher potency of febuxostat. XOis would be more suitable than uricosurics to treat older patients with gout due to the high prevalence of chronic kidney disease (CKD) in older patients. However, allopurinol alone might not achieve the target serum uric acid levels below 6 mg/dL and CKD might confer an increased risk of allopurinol induced cutaneous adverse reactions in older patients. Furthermore, as well as the later analysis of CARES participants who were lost to follow-up, data from the FAST trial and real-world studies suggest non-inferior CV safety for febuxostat compared to allopurinol even in the presence of CV diseases. Thus, febuxostat use in older patients with renal impairment may be more positively considered. The combination therapy of a novel uricosuric, verinurad, plus febuxostat reduced albuminuria in hyperuricemic patients with type 2 diabetes and CKD in a phase 2a trial, and further RCTs are awaited. Finally, the sodium-glucose cotransporter-2 inhibitor class of oral hypoglycemic agents, known to exert beneficial CV and renal effects independent of glycemic control, have shown a uricosuric effect and could be used as adjunctive therapy in older patients with cardiorenal comorbidities.

Clinical features, treatment outcomes and prognostic factors of allopurinol-induced DRESS in 52 patients

WHAT IS KNOWN AND OBJECTIVE

Allopurinol-induced drug reaction with eosinophilia and systemic symptoms (DRESS) is a rare but serious and potentially life-threatening drug hypersensitivity syndrome. In this study, we aimed to investigate the clinical features, treatment outcomes, and prognostic factors of allopurinol-induced DRESS.

METHODS

Case reports of allopurinol-induced DRESS published by China from January 2000 to August 2021 were retrieved from CNKI, Wan Fang, VIP, and PubMed databases for analysis.

RESULTS AND DISCUSSION

This study included 52 patients, consisting of 41 (78.8%) males and 11 (21.2%) females (M:F = 3.7:1). The mean of age was 56.1 ± 17.1 years (range: 18-86 years). The mean of latency periods was 24.6 ± 15.0 days (range:1-63 days). Most patients presented with fever, cutaneous eruption, eosinophilia, lymphadenopathy, and facial edema. 36/52 (69.2%) patients showed two or more internal organs involved. Liver and kidney injuries were the most common visceral manifestation. Pulmonary involvement (34.6%), cardiac involvement (25.0%) and gastrointestinal involvement (21.2%) were relatively less known but severe complications. 2/52 (3.8%) patients showed nervous system involved, presenting as leukoencephalopathy or peripheral neuropathy. 2/52 (3.8%) patients presented with secondary hemophagocytic lymphohistiocytosis.1/52 (1.9%) patient developed pure red cell aplasia and 1/52 (1.9%) patient developed painless thyroiditis. HLA*B 58:01 allele was tested in 18/52 (34.6%) patients. 16/18 (88.9%) cases were positive. 48/52 (92.3%) patients were treated with systemic corticosteroids. 16/52 (30.8%) patients were cured, 23/52 (44.2%) patients received partial recovery, and 13/52 (25.0%) patients were died. Septic shock, gastrointestinal bleeding and multiple organ failure were the leading causes of death. Advanced age, underlying cardiovascular disease, chronic kidney disease and high dose of allopurinol, infection and internal organ involvement (including kidney, heart, lung and gastrointestinal tract) were risk factors for death.

WHAT IS NEW AND CONCLUSION

We explored clinical features, treatment outcomes and prognostic factors of 52 allopurinol-induced DRESS cases in China. Ethnicity, especially Han Chinese, and positive HLA-B*58:01 allele are the clearest risk factors so far. Advanced age, underlying cardiovascular disease, chronic kidney disease and high dose of allopurinol, infection and internal organ involvement (including kidney, heart, lung and gastrointestinal tract) were associated with poorer outcomes. Early identification and discontinuation of the causative drug are crucial to the management of DRESS. For patients with severe disease, corticosteroids are recommended as the first-line therapy. However, further studies are needed to address diagnostic criteria of DRESS for early diagnosis, as well as to develop standardized corticosteroid treatment regimens.

Acylation of Anthocyanins and Their Applications in the Food Industry: Mechanisms and Recent Research Advances

Anthocyanins are extensively used as natural non-toxic compounds in the food industry due to their unique biological properties. However, the instability of anthocyanins greatly affects their industrial application. Studies related to acylated anthocyanins with higher stability and increased solubility in organic solvents have shown that the acylation of anthocyanins can improve the stability and fat solubility of anthocyanins. However, relevant developments in research regarding the mechanisms of acylation and applications of acylated anthocyanins are scarcely reviewed. This review aims to provide an overview of the mechanisms of acylation and the applications of acylated anthocyanins in the food industry. In the review, acylation methods, including biosynthesis, semi-biosynthesis, and chemical and enzymatic acylation, are elaborated, physicochemical properties and biological activities of acylated anthocyanins are highlighted, and their application as colourants, functionalizing agents, intelligent indicators, and novel packaging materials in the food industry are summarized. The limitations encountered in the preparation of acylated anthocyanins and future prospects, their applications are also presented. Acylated anthocyanins present potential alternatives to anthocyanins in the food industry due to their functions and advantages as compared with non-acylated analogues. It is hoped that this review will offer further information on the effective synthesis and encourage commercialization of acylated anthocyanins in the food industry.

Egyptian consensus on treat-to-target approach of gout: evidence-based clinical practice guidelines for the management of gout

Introduction

New therapies, management approaches, and evidence regarding the management of gout have become available over the past years. This triggered the need for an updated recommendation for gout management. Through an up-to-date consensus evidence-based clinical practice guideline for the management of gout including recommendations for management of gout flares, optimum usage of urate lowering therapy for chronic gout, as well as patient education and lifestyle guidance. A wide systematic literature review was performed, and evidence-based recommendations were extrapolated, based on 16-key questions identified according to population, intervention, comparator, and outcomes (PICO) approach. These were evaluated by a panel consisted of 17 rheumatology experts via online surveys over a 2-round Delphi process. The purpose of this study is to offer an updated, consensus-evidence-based, and in the meantime patient-focused, expert recommendations for the treat-to-target approach of gout management.

Results

Results revealed that after round 2 ended, a total of 30-recommendation items, categorized into 10 domains, were obtained. Agreement with the recommendations (rank 7–9) ranged from 90 to 100%. Consensus was reached (i.e., ≥ 75% of respondents strongly agreed or agreed) on the wording, the grade of recommendation, and level of evidence of all the 30 clinical standards identified by the scientific committee.

Conclusions

This guideline provides updated evidence-based recommendations for the prevention and treatment of acute as well as chronic gout. This guideline provides an approach for physicians and patients making decisions on the management of gout. It will also facilitate improvement and uniformity of care.

Management and Cure of Gouty Arthritis

Gout is the most common inflammatory arthritis in the United States. Gouty arthritis is associated with significant morbidity and mortality and is the result of chronic hyperuricemia. Gout is effectively managed and potentially cured by decreasing the overall urate burden with serum urate-lowering therapy. When serum urate is maintained at less than 6.0 mg/dL, urate deposition is resolved, and gout can be cured. Unfortunately, because of less than optimal physician monitoring and dose escalation, many patients do not achieve these urate levels.

Update on gout management: what is old and what is new

PURPOSE OF REVIEW

The global burden of gout is rising, as are the prevalence of associated comorbidities, all-cause mortality and societal costs. In this review, we discuss recent advances in epidemiology and treatment strategies for gout.

RECENT FINDINGS

Genetic factors and obesity are prominent contributors to hyperuricemia and gout, while dietary factors contribute to less variance in serum urate, though can still have some contribution to population attributable risk. A consensus statement by the Gout, Hyperuricemia and Crystal-Associated Disease Network outlined appropriate terminology regarding gout, which will aid in communication about various aspects of the disease. The 2020 American College of Rheumatology gout guideline offers comprehensive evidence-based recommendations for the management of hyperuricemia using urate-lowering therapy, prophylaxis when initiating urate-lowering therapy, treatment of gout flare and adjunctive management strategies. There is improved understanding of risk factors for allopurinol hypersensitivity syndrome and well tolerated use of allopurinol in chronic kidney disease. Trial data have provided new insights regarding cardiovascular risk with febuxostat. Several new drug therapies are being tested for both urate-lowering efficacy and gout flare management.

SUMMARY

Although there have been significant advances in understanding of risk factors and treatment approaches, gout remains suboptimally managed. There is substantial need for improving gout management efforts and gout education among patients and clinicians.

Safety and efficacy of SHR4640 combined with febuxostat for primary hyperuricemia: a multicenter, randomized, double-blind, phase II study

Background:

To evaluate the safety, tolerability, and efficacy of SHR4640, a highly selective urate transporter-1 inhibitor, in combination with febuxostat, in patients with primary hyperuricemia.

Methods:

In this randomized, double-blind, parallel-controlled phase II study, patients whose fasting serum uric acid (sUA) levels were ⩾ 480 μmol/L at screening with gout or sUA levels were ⩾ 420 μmol/L lasting for at least 3 months without gout, either with sUA levels ⩾ 540 μmol/L at screening or sUA levels ⩾ 480 μmol/L with comorbidities at screening, were enrolled. Patients were randomized (1:1:1) to receive SHR4640 10 mg plus febuxostat 80 mg, SHR4640 10 mg plus febuxostat 40 mg, and SHR4640 5 mg plus febuxostat 20 mg orally once daily. The primary end point was the incidence of treatment-emergent adverse events (TEAEs).

Results:

A total of 93 patients were randomized and received treatment. TEAEs occurred in 55.9% of patients. The incidence of TEAEs was comparable among all the groups. Serious TEAEs occurred in one patient (1.1%), with no deaths observed. The proportion of patients who achieved the target sUA levels by week 4 was 79.3%, 96.6%, and 75.0% in the SHR4640 10 mg plus febuxostat 80 mg, SHR4640 10 mg plus febuxostat 40 mg, and SHR4640 5 mg plus febuxostat 20 mg groups, respectively. The mean percent reduction of sUA was 59.7%, 63.7%, and 41.8%, respectively.

Conclusion:

SHR4640 plus febuxostat exhibited a tolerable safety profile and substantial sUA lowering activity in patients with primary hyperuricemia.

Registration:

www.chinadrugtrials.org.cn; CTR 20192429

What's new on the front-line of gout pharmacotherapy?

INTRODUCTION

Gout is the most common form of inflammatory arthritis affecting millions of people around the world. Painful flares and tophaceous deposits can be debilitating, reducing quality of life among those affected and putting strain on health care systems.

AREAS COVERED

This review provides an overview of the treatment of gout for flare pain management and lowering serum urate. Firstline agents are discussed with emphasis on emerging evidence. Novel therapies are also covered.

EXPERT OPINION

Lifestyle modifications form a part of gout prevention. Regarding gout flare pharmacotherapy NSAIDs, colchicine and glucocorticoids are first line agents. The IL-1β antagonists also are highly effective for arresting flares but their cost-effectiveness render them as salvage therapies. Allopurinol is an agent of first choice for urate lowering therapy (ULT). In South East Asian and Black populations screening for HLA*B58:01 mutation is a cost-effective approach to decrease the occurrence of the rare but potentially very serious allopurinol hypersensitivity syndrome (AHS.). Febuxostat is another efficacious urate lowering therapy but it has received U.S. FDA black box warning for cardiovascular safety and careful consideration is warranted before its initiation in patients with high cardiovascular risk. Novel uricosurics are a class for continued drug development; verinurad and arhalofenate are agents with future promise. For patients with recalcitrant gout, pegloticase is another effective option in the rheumatologist's armamentarium. Its immunogenicity significantly threatens the achievement of sustained urate lowering responses. Abrogating pegloticase's immunogenicity with immunomodulatory co-therapy may lend to sustained efficacy.

Anti-gout Medications and Risk of Cardiovascular Disease: A Nested Case-Control Study

Introduction: Gout is the leading cause of inflammatory arthritis and is also correlated with multiple comorbidities, including cardiovascular disease (CVD), whose future risk can be lowered by urate-lowering therapy (ULT) in gout patients. It is, however, still not clear whether its effect is associated with the days of usage and the adherence rate of ULT. Methods: Data were collected from Taiwan's National Health Insurance Research Database. The study period was from 1999/1/1 to 2013/12/31. In addition, patients with newly diagnosed gout from 2000 to 2012 and usage of antigout preparations (allopurinol or benzbromarone) within half a year among age ≥20 years old were enrolled in the study. The outcome of interest is CVD. New diagnosis of CVD after half a year of diagnosis of gout was included in the CVD group. Moreover, conditional logistic regression was used to evaluate the odds ratio of CVD in relation to the days of usage and to the adherence rate of ULT after the adjustment for potentially confounding variables. Results: A total of 3,706 gout patients with and without CVD have been included in the final analysis after a 1:1 propensity score that matched for age, sex, comorbidities, aspirin, and statin. The days of usage of allopurinol was <180 days and benzbromarone, in its turn, presupposed a higher risk of CVD. The adherence rate of allopurinol and benzbromarone at ≥ 0.7 both have a lower CVD risk: allopurinol (adjusted OR: 0.66 95% CI: 0.46-0.96), benzbromarone (adjusted OR: 0.68 95% CI: 0.50-0.91). The subgroup analysis revealed an adherence rate of ≥0.7 of ULT with a lower CVD was only found to be present in males and at age <65. Furthermore, the correlations were more pronounced in the ischemic heart disease subgroup than in the cerebrovascular disease group. Conclusion: This study reveals that gout patients taking ULT (allopurinol and benzbromarone) with an adherence rate of ≥0.7 are at a lower risk of developing CVD, especially with a younger age (<65) and if they are male. On top of this, the benefit is more pronounced in ischemic heart disease. Despite further prospective trials needing to be warranted to confirm our findings, health care providers may, bearing these conclusions in mind, emphasize the importance of adherence to ULT in gout patients.

Treatment advances in gout

The purpose of gout treatment is to alleviate symptoms of flares, prevent flares from recurring by lowering serum urate, and minimize structural joint damage and functional impairment. In recent years, several new medications to treat gout have been developed, and novel agents continue to be investigated, in addition to several long-established treatments. Although a number of effective therapies are available, optimal management and outcomes are frequently not achieved due to physician under prescribing of urate-lowering therapy (ULT) and poor adherence with therapy when it is prescribed. This article reviews recent developments in the management of gout with reference to recently published clinical guidelines, outlines some important questions regarding the safety and efficacy of particular agents, and remaining gaps in our knowledge about the most effective strategies for using currently available treatments.

Management of gout in chronic kidney disease: a G-CAN Consensus Statement on the research priorities

Gout and chronic kidney disease (CKD) frequently coexist, but quality evidence to guide gout management in people with CKD is lacking. Use of urate-lowering therapy (ULT) in the context of advanced CKD varies greatly, and professional bodies have issued conflicting recommendations regarding the treatment of gout in people with concomitant CKD. As a result, confusion exists among medical professionals about the appropriate management of people with gout and CKD. This Consensus Statement from the Gout, Hyperuricemia and Crystal-Associated Disease Network (G-CAN) discusses the evidence and/or lack thereof for the management of gout in people with CKD and identifies key areas for research to address the challenges faced in the management of gout and CKD. These discussions, which address areas for research both in general as well as related to specific medications used to treat gout flares or as ULT, are supported by separately published G-CAN systematic literature reviews. This Consensus Statement is not intended as a guideline for the management of gout in CKD; rather, it analyses the available literature on the safety and efficacy of drugs used in gout management to identify important gaps in knowledge and associated areas for research.

Predominant HLA Alleles and Haplotypes in Mild Adverse Drug Reactions Caused by Allopurinol in Vietnamese Patients with Gout

Allopurinol (ALP) is commonly used as a drug for gout treatment. However, ALP is known to cause cutaneous adverse reactions (CARs) in patients. The HLA-B^*58:01 allele is considered a biomarker of severe CAR (SCAR) in patients with gout, with symptoms of Stevens Johnson syndrome, and with toxic epidermal necrolysis. However, in patients with gout and mild cutaneous adverse drug reactions (MCARs), the role of HLA-allele polymorphisms has not been thoroughly investigated. In this study, 50 samples from ALP-tolerant patients and ALP-induced MCARs patients were genotyped in order to examine the polymorphisms of their HLA-A and HLA-B alleles. Our results showed that the frequencies of HLA-A^*02:01/HLA-A^*24:02 and HLA-A^*02:01/HLA-A^*29:01, the dual haplotypes in HLA-A, in patients with ALP-induced MCARs were relatively high, at 33.3% (7/21), which was HLA-B^*58:01-independent, while the frequency of these dual haplotypes in the HLA-A locus in ALP-tolerant patients was only 3.45% (1/29). The HLA-B^*58:01 allele was detected in 38% (8/21) of patients with ALP-induced MCARs, and in 3.45% (1/29) of ALP-tolerant patients. Notably, although HLA-B^*58:01 may be a cause for the occurrence of MCARs in patients with gout, this correlation was not as strong as that previously reported in patients with SCAR. In conclusion, in addition to the HLA-B^*58:01 allele, the presence of the dual haplotypes of HLA-A^*02:01/HLA-A^*24:02 and/or HLA-A^*02:01/HLA-A^*29:01 in the HLA-A locus may also play an important role in the appearance of ALP-induced MCARs in the Vietnamese population. The obtained primary data may contribute to the development of suitable treatments for patients with gout not only in Vietnam but also in other Asian countries.

Early versus Late Allopurinol Initiation in Acute Gout Flare (ELAG): a randomized controlled trial

OBJECTIVE

Currently available guidelines on urate-lowering therapy (ULT) initiation in acute gout flare are conflicting. We compared the time to complete resolution of acute gout flare between early and late allopurinol initiation.

METHODS

This 28-day, randomized controlled, open-label trial included patients with crystal-proven gout who were presented with acute gout flare within 72 h of arthritis onset. Exclusion criteria were advanced renal failure, ongoing ULT, and presence of the HLA-B*5801 allele. Allopurinol was used on days 1 and 14 in early and late groups, respectively. Primary outcome was time to complete arthritis resolution, and secondary outcomes were time to clinical resolution; arthritis relapse; laboratory parameters; and adverse events.

RESULTS

One hundred seventeen patients were randomized to early and late allopurinol groups (n = 59 and 58, respectively). One patient in each group was lost to follow-up; therefore, 115 patients were included in the modified intention-to-treat analysis. Baseline characteristics were comparable between the groups. The median time to complete resolution was not significantly different between the early and late allopurinol groups (6 [5-14] and 6 [5-7] days, respectively; p = 0.14). The median time to clinical resolution was 4 [3-6] days in both groups (p = 0.12). Other secondary outcomes were not significantly different. Serious adverse events did not occur in either group.

CONCLUSIONS

Early allopurinol initiation during an acute gout flare did not lead to significant changes in time to resolution, flare recurrence, and inflammatory markers. Key Points • Allopurinol Initiation in Gout.

Association of urate-lowering drugs with the risk of future urolithiasis in patients with gout: A population-based nested case-control study

BACKGROUND

Patients with gout have an increased risk of urolithiasis and usually need urate-lowering therapy (ULT) for the prevention of disease progression. However, there is a paucity of clinical data regarding the risk of future urolithiasis in ULT users.

METHODS

This nested case-control study was performed using the Taiwan National Health Insurance Research Database. The aim of this study was to examine whether ULT (xanthine oxidase inhibitors [XOIs] or uricosuric agents) is associated with risk of future urolithiasis in patients with gout. Data were collected from January 2000 to December 2012.

RESULTS

This study included 2307 case patients and 2307 matched controls. Case patients had gout that developed into urolithiasis, and control patients had gout but were not diagnosed with urolithiasis during the study period. Patients had a mean age of 56.3 years at diagnosis of gout, and 83.2% were male patients. No association was detected between use of XOIs or uricosuric agents and risk of future urolithiasis. Furthermore, there was no significant difference in the risk of future urolithiasis in patients exposed to various cumulative days of XOI or uricosuric prescriptions.

CONCLUSION

The present study provides evidence that neither XOIs nor uricosuric agents are associated with risk of future urolithiasis in patients with gout. Before the availability of more clinical evidence, ensuring high fluid intake and prospective monitoring of urolithiasis development are still important for uricosuric agent users.

Gout

Gout is a common and treatable disease caused by the deposition of monosodium urate crystals in articular and non-articular structures. Increased concentration of serum urate (hyperuricaemia) is the most important risk factor for the development of gout. Serum urate is regulated by urate transporters in the kidney and gut, particularly GLUT9 (SLC2A9), URAT1 (SLC22A12), and ABCG2. Activation of the NLRP3 inflammasome by monosodium urate crystals with release of IL-1β plays a major role in the initiation of the gout flare; aggregated neutrophil extracellular traps are important in the resolution phase. Although presenting as an intermittent flaring condition, gout is a chronic disease. Long-term urate lowering therapy (eg, allopurinol) leads to the dissolution of monosodium urate crystals, ultimately resulting in the prevention of gout flares and tophi and in improved quality of life. Strategies such as nurse-led care are effective in delivering high-quality gout care and lead to major improvements in patient outcomes.

The Management of Gout in Renal Disease

Gout, a debilitating inflammatory arthritis, currently affects more than 9 million Americans. Hyperuricemia, the laboratory abnormality associated with the development of gout, also occurs in a significant number of patients with chronic kidney disease (CKD), a condition that affects approximately 14% of the US population. Several recent studies have attempted to provide a definitive link between the presence of hyperuricemia and progression of CKD; however, the treatment of asymptomatic hyperuricemia in CKD is not supported by recent randomized controlled trials. The pharmacology of acute gout flares and urate lowering is complicated in patients who also have evidence of CKD, primarily because of an increased risk of medication toxicity. Recipients of kidney transplants are particularly at risk of debilitating gout and medication toxicity. We review the available data linking CKD, gout, and hyperuricemia, providing practice guidelines on managing gout in CKD patients and kidney transplant recipients. We advocate for much greater involvement of nephrologists in the management of gout in renal patients.

Management and Cure of Gouty Arthritis

Gout is the most common inflammatory arthritis in the United States. Gouty arthritis is associated with significant morbidity and mortality and is caused by hyperuricemia. Gout is effectively managed and potentially cured by decreasing the overall urate burden with serum urate-lowering therapy. When serum urate is maintained at less than 6.0 mg/dL urate deposition is resolved and gout can be cured. Unfortunately, owing to a lack of physician monitoring and dose escalation the majority of patients do not achieve these urate levels.

Managing hyperuricemia and gout in chronic kidney disease: a clinical conundrum

PURPOSE OF REVIEW

There is controversy regarding the impact of hyperuricemia on the progression of chronic kidney disease (CKD), and gout remains sub optimally managed in this population. We discuss the prescribing of drugs for the treatment of gout in patients with CKD.

RECENT FINDINGS

There is a lack of consensus from expert guidelines, and prescribers have concerns regarding the risk of adverse reactions from medicines used to treat gout. These situations appear to contribute to suboptimal management of gout in this cohort. Recent data have challenged the role of urate lowering therapy (ULT) in the management of asymptomatic hyperuricemia in CKD.

SUMMARY

ULT should be commenced in all patients with severe, recurrent disease, tophaceous gout and evidence of joint damage. Most international guidelines recommend a treat-to-target approach for the management of gout. In CKD, ULT should be started at low dose with up titration adjusted to serum urate levels, rather than being based on the creatinine clearance. If patients fail first-line therapy, alternative agents are utilized, the specific agent depending on ease of access, burden of disease and other comorbidities. This approach should be incorporated into routine practice to ensure optimal treatment of gout in CKD. More research is required to investigate whether treatment of asymptomatic hyperuricemia has clinical benefits.

Association Between Use of Anti-gout Preparations and Dementia: Nested Case-Control Nationwide Population-Based Cohort Study

Objectives: Gout is the most common form of inflammatory arthritis and was found to be independently associated with incident dementia in the elderly. However, the associations between anti-gout preparations and dementia were not well-studied.

Methods: Data were collected from Taiwan's National Health Insurance Research Database (NHIRD). A 2005–2013 retrospective cohort study was conducted, and all investigated subjects were identified by International Statistical Classification of Diseases and Related Health Problems, 9th Revision, Clinical Modification. Conditional logistic regression was used to evaluate the odds ratio of dementia in relation to different gout preparations (benzbromarone, allopurinol, sulfinpyrazone, probenecid) and number of days of anti-gout preparation use, after adjustment for potential confounding variables.

Results: A total of 3,242 gout patients with and without dementia were selected from the NHIRD and included in the final analysis after 1:1 matching for age, gender, and diagnosis year of gout. In the anti-gout preparations, only use of Benzbromarone decreased the risk of dementia (adjusted OR, 0.81; 95% CI, 0.68–0.97). The result of the subgroup analysis revealed a trend toward a lower risk of dementia with longer use of benzbromarone. Use of benzbromarone for ≥180 days showed a significantly lower risk of dementia (adjusted OR, 0.72; 95% CI, 0.58–0.89). Moreover, the protective effect was more pronounced in males compared with females.

Conclusion: This cohort study reveals that gout patients taking benzbromarone are at a decreased risk of developing incident dementia, especially with longer use and in male. Further prospective trials are warranted to confirm our findings.

Genetic Markers for Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis in the Asian Indian Population: Implications on Prevention

This review attempts to collate all the studies performed in India or comprising a population originating from India and to find out if there is an association between the HLA (human leucocyte antigen) type of individual and development of Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) subsequent to medication use. The authors performed a PubMed search of all articles published in English from 2009 to 2019 for articles that studied HLA type in patients who developed SJS/TEN after intake of a specific drug in the Asian Indian population or in individuals of Asian Indian origin. The selection criteria were satisfied by a total of 11 studies that reported HLA associations with specific drugs, which induced SJS/TEN, mainly anti-epileptic drugs, and cold medicine/non-steroidal anti-inflammatory drugs. These studies involved a small number of patients, and hence, there is limited evidence to conclude if these associations can be extrapolated to a larger population of the same ethnicity. Similar multi-center studies need to be conducted with a larger sample size to confirm these associations. This would have implications in policy making and for understanding the potential of using genetic markers as a screening tool before prescribing a drug to a patient, which might make them susceptible to developing a potentially life-threatening disease such as SJS/TEN. This is possibly the only mode of primary prevention for this potentially fatal severe cutaneous adverse drug reaction.

Therapeutic Strategies for the Treatment of Chronic Hyperuricemia: An Evidence-Based Update

This article aims to critically review the evidence on the available therapeutic strategies for the treatment of hyperuricemia. For this reason, several papers were reviewed. Xanthine oxidase inhibitors are the safest and most effective uric acid lowering drugs for the management of chronic hyperuricemia, while the efficacy of uricosuric agents is strongly modulated by pharmacogenetics. Emergent drugs (lesinurad, peglotidase) were found to be more effective for the acute management of refractory hyperuricemia, but their use is supported by a relatively small number of clinical trials so that further well-designed clinical research is needed to deepen their efficacy and safety profile.

Efficacy and safety of urate-lowering therapy in people with kidney impairment: a GCAN-initiated literature review

OBJECTIVES

The aim was to evaluate the efficacy, defined as achieving target serum urate <6.0 mg/dl, and safety of urate-lowering therapies (ULTs) for people with gout and chronic kidney disease (CKD) stages 3-5.

METHODS

PubMed, The Cochrane Library and EMBASE were searched from 1 January 1959 to 31 January 2018 for studies that enrolled people with gout, who had an estimated glomerular filtration rate (eGFR) or creatinine clearance (CrCl) of <60 ml/min and exposure to allopurinol, febuxostat, probenecid, benzbromarone, lesinurad or pegloticase. All study designs other than case reports were included, except for people on dialysis, for whom we did include case reports.

RESULTS

There were 36 reports with an analysis of efficacy and/or safety based upon renal function: allopurinol (n = 12), febuxostat (n = 10), probenecid (n = 3), benzbromarone (n = 5), lesinurad (n = 5) and pegloticase (n = 1). There were 108 reports that involved people with gout and renal impairment but did not contain any analysis on efficacy and/or safety based upon renal function: allopurinol (n = 84), febuxostat (n = 14), benzbromarone (n = 1), lesinurad (n = 3) and pegloticase (n = 6). Most studies excluded people with more severe degrees of renal impairment (eGFR or CrCl of <30 ml/min). For allopurinol, in particular, there was significant variability in the dose of drug used and the efficacy in terms of urate lowering, across all levels of renal impairment.

CONCLUSION

There is a lack of evidence regarding the efficacy and/or safety of currently used ULTs according to different levels of renal function. Future studies should include patients with CKD and should report study outcomes stratified by renal function.

Clinical Effects of Xanthine Oxidase Inhibitors in Hyperuricemic Patients

This review aims to critically present the available clinical evidence supporting the treatment of chronic hyperuricemia with xanthine oxidase inhibitors. For this reason, the studies published on uric acid (UA)-lowering drugs in the English language from 2000 to August 2019 have been carefully reviewed. The terms "serum uric acid," "xanthine oxidase," "allopurinol," "febuxostat," and "topiroxostat" were incorporated into an electronic search strategy, alone and in combinations, in both MEDLINE (National Library of Medicine, Bethesda, MD) and the Cochrane Register of Controlled Trials (The Cochrane Collaboration, Oxford, UK). Even if new urate-lowering drugs seem of particular efficacy for acute treatment of refractory hyperuricemia, their use is supported by relatively small clinical evidence. On the contrary, large long-term clinical trials have demonstrated that xanthine oxidase inhibitors (XOIs, namely, allopurinol and febuxostat) are effective, safe, and relatively well-tolerated in most of the patients. They have mainly been tested in the elderly, in patients affected by chronic diseases such as heart failure and cancer, and in patients taking a large number of drugs, confirming their safety profile. Recent data also show that they could exert some positive effects on vascular health, renal function, and glucose metabolism. Their cost is also low. In conclusion, XOIs remain the first choice of UA-lowering drug for chronic treatment.

Renal effects of uric acid: hyperuricemia and hypouricemia

The prevalence of chronic kidney disease (CKD) is increasing worldwide. Although hyperuricemia has been associated with CKD in many studies, it remains controversial whether this is the cause or the result of decreased renal function. Recent observational studies of healthy populations and patients with CKD have reported that uric acid (UA) has an independent role in the development or progression of CKD. Experimental studies have shown several potential mechanisms by which hyperuricemia may cause or promote CKD. However, other reports have indicated an association between hypouricemia and CKD. This opposing effect is hypothesized to occur because UA is a major antioxidant in human plasma and is associated with oxidative stress. In this article, we discuss the potential association between UA imbalance and CKD and how they can be treated.

Risk factors for cutaneous reactions to allopurinol in Kinh Vietnamese: results from a case-control study

OBJECTIVE

The aim of this study was to investigate risk factors for cutaneous adverse reactions (CARs) in Kinh Vietnamese.

METHODS

All patients were prospectively recruited in Ho Chi Minh City. Presence of the HLA-B*58:01 allele was determined by real-time PCR-sequence-specific amplification by using the PG5801 Detection Kit (Pharmigene, Taipei). Patients with severe (SCARs) and mild (MCARs) CARs and controls were compared for differences in features prospectively collected, and odds ratios (ORs) with 95% confidence intervals (CIs) were estimated.

RESULTS

On comparing 32 patients with SCARs and 395 tolerant controls, we identified eight strong risk factors: increased age (OR 15.1 [95% CI 5.8-40.1], P < 0.0001), female sex (OR 333 [40-43,453], P < 0.0001), allopurinol for asymptomatic hyperuricemia (OR 955 [120-125,847], P < 0.0001), allopurinol starting dose > 150 mg (OR 316 [101-122], P < 0.0001), diuretics intake (OR 304 [35-40,018], P < 0.0001), eGFR < 60 ml/min/1.73 m² (OR 100 [32-353], P < 0.0001), history of allopurinol-induced skin reaction (OR 78 [6-10,808], P = 0.004), and HLA-B*58:01 carriage (OR 147 [45-746], P < 0.0001). HLA-B*58:01 allele frequency in controls was 7.3%. For MCARs (n = 74), risk factors were eGFR < 60 ml/min/1.73 m² (OR 4.9 [1.61-14.6], P = 0.006), history of allopurinol-induced skin reaction (OR 27 [2-3777], P = 0.01), and asymptomatic hyperuricemia (OR 27 [2-3777], P = 0.01).

CONCLUSION

This study confirmed 8 risk factors, including HLA-B*58:01, for SCARs and identified 3 risk factors for MCARs in Kinh Vietnamese. HLA-B*58:01 genotyping could guide the indication for allopurinol in Kinh Vietnamese patients with gout.