The urate-lowering efficacy and safety of febuxostat in the treatment of the hyperuricemia of gout: the CONFIRMS trial

Effect of Hepatic Impairment on the Pharmacokinetics and Pharmacodynamics of SHR4640, a Selective Human Urate Transporter 1 Inhibitor

This parallel-group, open-label Phase I study evaluated the effect of mild to moderate hepatic impairment on pharmacokinetics (PK), pharmacodynamics (PD), and safety of a single oral dose of SHR4640. Participants with mild or moderate hepatic impairment were enrolled, with each cohort consisting of eight individuals, alongside eight well-matched controls with normal hepatic function. The participants were administered 10 mg SHR4640, and blood samples were collected for PK evaluation over 72 h. Additionally, serum uric acid (sUA) levels were measured to assess PD changes. Safety was evaluated through adverse events, laboratory tests, vital signs, and electrocardiograms. The Cmax of SHR4640 decreased by 15.0% in the mild hepatic impairment group (geometric least squares means of the ratios [GMR] = 0.850, 90% CI: 0.701-1.03) and by 17.5% in the moderate hepatic impairment group (GMR = 0.825, 90% CI: 0.681-1.00). These reductions were not statistically significant compared to the normal hepatic function group. AUC0-t and AUC0-inf were similar across all groups, indicating that overall exposure to the drug was not clinical significantly affected by hepatic impairment. Apparent clearance and volume of distribution of SHR4640 showed no association with the severity of hepatic impairment as measured by the Child-Pugh score. There were no significant differences in the changes in sUA levels from baseline across different levels of hepatic function. SHR4640 is well tolerated in participants with mild or moderate hepatic impairment. Mild and moderate hepatic impairment did not have a clinically relevant impact on PK, PD, and safety of SHR4640. SHR4640 can be used in patients with mild to moderate hepatic impairment without the need for dose adjustment.

Projected Health and Economic Burden of Comorbid Gout and Chronic Kidney Disease in a Virtual US Population: A Microsimulation Study

INTRODUCTION

Gout, a common comorbidity of chronic kidney disease (CKD), is associated with high morbidity and healthcare utilization. However, a large proportion of gout remains undermanaged or untreated which may lead to worse patient outcomes and greater healthcare costs. This study estimates the present and future health and economic burden of controlled and uncontrolled gout in a virtual United States (US) CKD population.

METHODS

A validated microsimulation model was used to project the burden of gout in patients with CKD in the USA through 2035. Databases were utilized to build a virtual CKD population of "individuals" with controlled or uncontrolled gout. Modelling assumptions were made on the basis of the literature, which was sparse in some cases. Health and economic outcomes with the current care (baseline) scenario were evaluated, along with potential benefits of urate-lowering intervention scenarios.

RESULTS

The prevalence of comorbid gout and CKD in the USA was projected to increase by 29%, from 7.9 million in 2023 to 9.6 million in 2035 in the baseline scenario. Gout flares, tophi, and comorbidity development were also projected to increase markedly through 2035, with the economic burden of gout in the CKD population subsequently increasing from $38.9 billion in 2023 to $47.3 billion in 2035. An increased use of oral urate-lowering therapies in undermanaged patients, and pegloticase use in patients refractory to oral urate-lowering therapies were also project to result in 744,000 and 353,000 fewer uncontrolled gout cases, respectively, by 2035. Marked reductions in complications and costs ensued.

CONCLUSIONS

This study projected a substantial increase in comorbid gout and CKD. However, improved use of urate-lowering interventions could mitigate this growth and reduce the health and economic burdens of gout.

Managing Gout in Patients with Metabolic Syndrome

Gout is characterized by monosodium urate (MSU) crystal deposition secondary to hyperuricemia. Gout is associated with metabolic syndrome (MetS) and its related comorbid conditions such as cardiovascular disease (CVD). Major advances have been made in the comprehension of the link between MetS and gout. Despite observational studies suggesting an association between MetS-related conditions and hyperuricemia, there is no proof of causality. Most studies using Mendelian randomization did not find hyperuricemia as a causal factor for MetS-related conditions. In contrast, these conditions were found associated with hyperuricemia, which suggests a reverse causality. Among patients with gout, this high CVD risk profile implies the need for systematic screening for MetS-related conditions. Most international guidelines recommend systematic screening for and care of CVD and related risk factors in patients with gout. Some anti-hypertensive agents, such as losartan and calcium channel blockers, are able to decrease serum urate (SU) levels. However, there are potential interactions between gout management therapies and the treatment of metabolic diseases. Some data suggest that anti-inflammatory drugs used for gout flare treatment, such as colchicine or canakinumab, might have benefits for CVD. Regarding the impact of urate-lowering therapies on CVD risk, recent studies found a similar CVD safety profile for allopurinol and febuxostat. Finally, sodium-glucose cotransporter-2 inhibitors are promising for gout because of their ability to decrease SU levels and risk of recurrent flares. In this review, we focus on the clinical challenge of managing MetS in patients with gout, particularly older patients with co-medications.

Asymptomatic hyperuricemia: to treat or not a threat? A clinical and evidence-based approach to the management of hyperuricemia in the context of cardiovascular diseases

Asymptomatic hyperuricemia is defined by serum uric acid levels above 6.2 mg/dl in women and 7 mg/dl in men. In the presence of monosodium urate crystal formation and articular inflammation, hyperuricemia may become symptomatic (namely nephrolithiasis and gout). Uric acid results from purine catabolism and is at the centre of a complex metabolic interplay that involves oxidative stress, inflammation, renin-angiotensin-aldosterone system (RAAS) activation and insulin resistance. Uric acid levels present a continuous relation with conditions like hypertension and chronic kidney disease (CKD) and are reported to have an impact on risk of cardiovascular events. However, whether elevated uric acid is a causal agent and thus a possible therapeutic target is still uncertain and matter of further investigation. Treating symptomatic hyperuricemia involves lowering uric acid drugs and controlling inflammation. Urate-lowering agents are well tolerated but show minimal impact on cardiovascular events in patients with gout. Use of direct-acting urate-lowering agents in asymptomatic hyperuricemia associated with cardiovascular diseases does not warrant a clear benefit, whereas addressing cardiovascular issues with guideline-recommended therapies lowers uric acid and reduces the occurrence of cardiovascular events. Regular assessment of uric acid and clinical symptoms is advised before starting and renewing a urate-lowering treatment.

Comparison of Gout Flares With the Initiation of Treat-to-Target Allopurinol and Febuxostat: A Post-Hoc Analysis of a Randomized Multicenter Trial

OBJECTIVE

Initiating urate-lowering therapy (ULT) in gout can precipitate arthritis flares. There have been limited comparisons of flare risk during the initiation and escalation of allopurinol and febuxostat, administered as a treat-to-target strategy with optimal anti-inflammatory prophylaxis.

METHODS

This was a post-hoc analysis of a 72-week randomized, double-blind, placebo-controlled, noninferiority trial comparing the efficacy of allopurinol and febuxostat. For this analysis, the occurrence of flares was examined during weeks 0 to 24 when ULT was initiated and titrated to a serum urate (sUA) goal of less than 6 mg/dl (<5 mg/dl if tophi). Flares were assessed at regular intervals through structured participant interviews. Predictors of flare, including treatment assignment, were examined using multivariable Cox proportional hazards regression.

RESULTS

Study participants (n = 940) were predominantly male (98.4%) and had a mean age of 62.1 years with approximately equal proportions receiving allopurinol or febuxostat. Mean baseline sUA was 8.5 mg/dl and all participants received anti-inflammatory prophylaxis (90% colchicine). In a multivariable model, there were no significant associations of ULT treatment (hazard ratio [HR] 1.17; febuxostat vs allopurinol), ULT-dose escalation (HR 1.18 vs no escalation), prophylaxis type, or individual comorbidity with flare and no evidence of ULT-dose escalation interaction. Factors independently associated with flare risk during ULT initiation/escalation included younger age, higher baseline sUA, and absence of tophi.

CONCLUSION

These results demonstrate that gout flare risk during the initiation and titration of allopurinol is similar to febuxostat when these agents are administered according to a treat-to-target strategy using gradual ULT-dose titration and best practice gout flare prophylaxis.

A Genome-Wide Association Study of Oxypurinol Concentrations in Patients Treated with Allopurinol

Cohort studies have identified several genetic determinants that could predict the clinical response to allopurinol. However, they have not been commonly used for genome-wide investigations to identify genetic determinants on allopurinol metabolism and concentrations. We conducted a genome-wide association study of a prior cross-sectional investigation of patients from the Montreal Heart Institute Biobank undergoing allopurinol therapy. Four endpoints were investigated, namely plasma concentrations of oxypurinol, the active metabolite of allopurinol, allopurinol, and allopurinol-riboside, as well as allopurinol daily dosing. A total of 439 participants (mean age 69.4 years; 86.4% male) taking allopurinol (mean daily dose 194.5 mg) and who had quantifiable oxypurinol concentrations were included in the genome-wide analyses. Participants presented with multiple comorbidities and received concomitant cardiovascular medications. No association achieved the predefined genome-wide threshold values for any of the endpoints (all p > 5 × 10-8). Our results are consistent with prior findings regarding the difficulty in identifying genetic determinants of drug concentrations or pharmacokinetics of allopurinol and its metabolites, as well as allopurinol daily dosing. Given the size of this genome-wide study, collaborative investigations involving larger and diverse cohorts may be required to further identify pharmacogenomic determinants of allopurinol and measure their clinical relevance to personalize allopurinol therapy.

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.

Superiority of Low-Dose Benzbromarone Add-On to Low-Dose Febuxostat Compared With Febuxostat Monotherapy in Gout With Combined-Type Hyperuricemia

OBJECTIVE

There is an unmet need for simpler urate-lowering therapy (ULT) regimens that achieve the serum urate target and improve the overall quality of gout care. We report a comparative effectiveness trial of febuxostat monotherapy versus benzbromarone add-on to low-dose febuxostat in gout specifically with combined renal urate underexcretion and overload.

METHODS

A prospective randomized trial was conducted on patients with combined-type hyperuricemia and estimated glomerular filtration rate >60 mL/min/1.73 m2 1:1 randomly assigned to febuxostat and benzbromarone combination therapy (initially febuxostat at 20 mg/day, with benzbromarone at 25 mg/day added onto 20 mg/day of febuxostat if not at target) or febuxostat monotherapy (initially 20 mg/day, escalating to 40 mg/day if not at target). The primary end point at 12 weeks was the proportion achieving a serum urate (SU) level <360 μmol/L. Other outcomes included altered liver and kidney function, new-onset urolithiasis, and gout flares.

RESULTS

There were 250 participants randomized; 219 completed 12-week treatment. More patients in the febuxostat and benzbromarone combination group achieved the SU target compared to patients in the febuxostat monotherapy group (75.5% vs 47.7%; odds ratio 3.37 [95% confidence interval 1.90-5.98]). Safety profiles were comparable between the two groups.

CONCLUSION

Simply adding on low-dose benzbromarone (25 mg/day) to low-dose (20 mg/day) febuxostat showed superior urate lowering compared to febuxostat monotherapy in gout with a combined-type hyperuricemia. For selected patients, expedited achievement of the SU target in more than 75% of patients using one titration step and low xanthine oxidase inhibitor and uricosuric doses is a potential alternative to standard ULT regimens.

Pathophysiology and Treatment of Gout Arthritis; including Gout Arthritis of Hip Joint: A Literature Review

Gout is triggered by the accumulation of uric acid in the body, leading to hyperuricemia. Genetic, metabolic, and environmental factors can influence this condition. Excessive uric acid buildup results in the formation of monosodium urate (MSU) crystals, which precipitate in specific areas of the body, including the joints, where they can cause symptoms of gout. While the acute and chronic symptoms of gout have been well-documented, diagnosis of gout affecting the hip joint poses significant challenges. The global incidence of gout, the most prevalent form of inflammatory arthritis, is on the rise. Evaluation of the clinical signs, laboratory results, and imaging results is generally required for diagnosis of gout in cases where MSU crystals have not been detected. Hyperuricemia is considered a primary cause of arthritis symptoms, and comprehensive guidelines for treatment are available. Therefore, the choice of medication is straightforward, and moderate effectiveness of treatment has been demonstrated. Gout is a chronic disease, requiring lifelong uric acid-lowering medications, thus application of a treatment strategy based on the target blood uric acid concentration is necessary. Consequently, cases of gout will likely be observed more frequently by hip surgeons in clinical scenarios in the future. The objective of this review is to provide an overview of the pathophysiology of gout and subsequently examine recent advances in diagnostic methods and therapeutic agents based on an understanding of its underlying mechanisms. In addition, literature on gout-related issues affecting the hip joint, providing a useful reference for hip surgeons is examined.

Cardiovascular Safety of Febuxostat in Patients With Gout or Hyperuricemia: A Systematic Review of Randomized Controlled Trials

INTRODUCTION

To this date, a causal relationship between febuxostat and cardiovascular disease remains controversial as comparison between trials can be challenging and may lead to misleading conclusions, especially when facing heterogeneous cardiovascular outcomes. We aimed to compare the cardiovascular outcomes in the most pertinent trials of febuxostat compared with controls.

METHODS

We searched electronic databases using a PICOS-style approach search strategy of randomized controlled trials (RCTs) on cardiovascular outcomes of febuxostat in patients with gout or hyperuricemia. We conducted a quality and risk of bias assessment of the included clinical trials. The definition of major adverse cardiovascular event as well as all reported cardiovascular outcomes were retrieved from every involved trial.

RESULTS

Of the 1173 records identified from all sources, 20 RCTs were included in the analysis. The mean duration of follow-up was 69.7 ± 81.5 weeks, and febuxostat dose ranged from 10 to 240 mg with 80 mg being the most commonly used dosage. Overall, the quality of evidence deriving from all RCTs showed concerns in most studies (65%). Major adverse cardiovascular event was defined in 7 of the 20 RCTs (35%), and cardiovascular outcome reporting was very heterogeneous. Overall, the data of cardiovascular safety of febuxostat were reassuring.

CONCLUSIONS

Our systematic review showed high level of concerns in quality assessment domains as well heterogeneous cardiovascular outcomes across included studies. Cardiovascular outcomes in the majority of White males with gout treated with febuxostat were reassuring when compared with allopurinol. Further studies are needed to draw conclusions in patients with severe cardiovascular disease.

Urate-Lowering Drugs and Muscle Injury: A Systematic Review and Network Meta-Analysis

Several urate-lowering drugs have been linked to muscle injury. This study investigated the association of oral urate-lowering drugs with the risk of muscle injury by performing a network meta-analysis of randomized and non-randomized controlled trials. A systematic search of MEDLINE, via PubMed, the ClinicalTrials.gov website, and the Cochrane Central Register of Controlled Trials was conducted to identify relevant studies with a primary outcome of "all muscle injuries." A random-effects model was used to perform a frequentist network meta-analysis to estimate whether there was significant heterogeneity among the studies. In total, 32 studies including 28,327 participants with 2694 (9.5%) "all muscle injuries" were assessed, and the overall risk of bias was judged to be low to moderate. No statistically significant differences were found between placebo and 6 urate-lowering therapies: allopurinol (risk ratio, RR, 1.05; 95% confidence interval, 95%CI, 0.63-1.73), febuxostat (RR 1.10, 95%CI 0.71-1.70), lesinurad (RR 7.00, 95%CI 0.31-160.36), lesinurad concomitant with allopurinol (RR 0.85, 95%CI 0.34-2.11), lesinurad concomitant with febuxostat (RR 1.97, 95%CI 0.55-7.03), and topiroxostat (RR 0.99, 95%CI 0.37-2.65). The findings suggest that there is little need to consider the risk of muscle injury when using urate-lowering drugs in the clinical setting.

Integrated Functions of Cardiac Energetics, Mechanics, and Purine Nucleotide Metabolism

Purine nucleotides play central roles in energy metabolism in the heart. Most fundamentally, the free energy of hydrolysis of the adenine nucleotide adenosine triphosphate (ATP) provides the thermodynamic driving force for numerous cellular processes including the actin-myosin crossbridge cycle. Perturbations to ATP supply and/or demand in the myocardium lead to changes in the homeostatic balance between purine nucleotide synthesis, degradation, and salvage, potentially affecting myocardial energetics and, consequently, myocardial mechanics. Indeed, both acute myocardial ischemia and decompensatory remodeling of the myocardium in heart failure are associated with depletion of myocardial adenine nucleotides and with impaired myocardial mechanical function. Yet there remain gaps in the understanding of mechanistic links between adenine nucleotide degradation and contractile dysfunction in heart disease. The scope of this article is to: (i) review current knowledge of the pathways of purine nucleotide depletion and salvage in acute ischemia and in chronic heart disease; (ii) review hypothesized mechanisms linking myocardial mechanics and energetics with myocardial adenine nucleotide regulation; and (iii) highlight potential targets for treating myocardial metabolic and mechanical dysfunction associated with these pathways. It is hypothesized that an imbalance in the degradation, salvage, and synthesis of adenine nucleotides leads to a net loss of adenine nucleotides in both acute ischemia and under chronic high-demand conditions associated with the development of heart failure. This reduction in adenine nucleotide levels results in reduced myocardial ATP and increased myocardial inorganic phosphate. Both of these changes have the potential to directly impact tension development and mechanical work at the cellular level. © 2024 American Physiological Society. Compr Physiol 14:5345-5369, 2024.

Effectiveness and safety of different doses of febuxostat compared with allopurinol in the treatment of hyperuricemia: a meta-analysis of randomized controlled trials

BACKGROUND

The prevalence of hyperuricemia has increased steadily with the continuous improvement of living standards. Some studies have reported the clinical effectiveness and safety of different doses of febuxostat in comparison with allopurinol in hyperuricemia treatment, but the sample sizes of the studies have been small, and the results have been inconsistent. We designed this meta-analysis to evaluate the effectiveness and safety of different doses of febuxostat compared with allopurinol in the treatment of hyperuricemia.

METHODS

The Cochrane Library, Embase, PubMed, Web of Science and ClinicalTrials.gov databases were searched to identify randomized controlled trials (RCTs) comparing the use of febuxostat and allopurinol for the treatment of hyperuricemia. The effectiveness and safety of different doses of febuxostat and allopurinol in treating hyperuricemia were assessed using meta-analysis.

RESULTS

A total of 11 randomized controlled trials were included in the meta-analysis. The results of the meta-analysis showed that the percentage of patients achieving serum uric acid levels of 6.0 mg/dL or less was higher among patients taking febuxostat (80 mg/d) than among patients taking allopurinol (200-300 mg/d) [RR = 1.79, 95% CI (1.55, 2.08), P < 0.00001]. However, there was no statistically significant difference in the percentage of patients achieving serum uric acid levels of 6.0 mg/dL or less between febuxostat (40 mg/d) and allopurinol (200-300 mg/d) [RR = 1.10, 95% CI (0.93, 1.31), P = 0.25]. There was also no statistically significant difference in the incidence of gout between the febuxostat (40 mg/d) and allopurinol (200-300 mg/d) [RR = 0.97, 95% CI (0.64, 1.49), P = 0.91] or between the febuxostat (80 mg/d) and allopurinol (200-300 mg/d) [RR = 1.13, 95% CI (0.81, 1.58), P = 0.48].No significant difference in the incidence of major adverse reactions as observed between the febuxostat (40 mg/d) and allopurinol (200-300 mg/d) [RR = 1.16; 95% CI (0.43, 3.16), P = 0.77] or between the febuxostat (80 mg/d) and allopurinol (200-300 mg/d) [RR = 1.06; 95% CI (0.79, 1.42), P = 0.70]. The incidence of adverse cardiovascular events did not differ significantly between the febuxostat (40 mg/d) and allopurinol (200-300 mg/d) [RR = 1.30; 95% CI (0.57, 2.95), P = 0.53] or between the febuxostat (80 mg/d) and allopurinol (200-300 mg/d) [RR = 1.79; 95% CI (0.74, 4.32), P = 0.20].

CONCLUSIONS

Febuxostat (80 mg/d) was associated with a higher percentage of patients achieving serum uric acid levels of 6.0 mg/dL or less than allopurinol (200-300 mg/d), however, febuxostat (80 mg/d) did not exhibit better efficacy in reducing the incidence of gout. More attention should be devoted to the adverse reactions caused by an increase in febuxostat doses.

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.

Past, present and future of xanthine oxidase inhibitors: design strategies, structural and pharmacological insights, patents and clinical trials

Xanthine oxidase, a molybdo-flavoenzyme, and an isoform of xanthine dehydrogenase both exist as xanthine oxidoreductase and are responsible for purine catabolism. Xanthine oxidase is more involved in pathological conditions when extensively modulated. Elevation of xanthine oxidase is not only the prime cause of gout but is also responsible for various hyperuricemia associated pathological conditions like diabetes, chronic wounds, cardiovascular disorders, Alzheimer's disease, etc. Currently available xanthine oxidase inhibitors in clinical practice (allopurinol, febuxostat and topiroxostat) suffer from fatal side effects that pose a serious problem to the healthcare system, raising global emergency to develop novel, potent and safer xanthine oxidase inhibitors. This review will provide key and systematic information about: a. design strategies (inspired from both marketed drugs in clinical practice and natural products), structural insights and pharmacological output (xanthine oxidase inhibition and associated activities) of various pre-clinical candidates reported by various research groups across the globe in the past two decades; b. patented xanthine oxidase inhibitors published in the last three decades and c. clinical trials and their outcomes on approved drug candidates. Information generated in this review has suggested fragment-based drug design (FBDD) and molecular hybridization techniques to be most suitable for development of desired xanthine oxidase inhibitors as one provides high selectivity toward the enzyme and the other imparts multifunctional properties to the structure and both may possess capabilities to surpass the limitations of currently available clinical drugs. All in combination will exclusively update researchers working on xanthine oxidase inhibitors and allied areas and potentially help in designing rational, novel, potent and safer xanthine oxidase inhibitors that can effectively tackle xanthine oxidase related disease conditions and disorders.

Hepatic Safety of Febuxostat and Allopurinol for Gout Patients: A Systematic Review of Randomized Controlled Trial

Purpose

This study aims to systematically review the hepatic safety of febuxostat and allopurinol in adult gout patients.

Methods

We searched for information using the following databases: PubMed, Cochrane Library, and Scopus. The inclusion criteria were to review all randomized controlled trials (RCT) that compared allopurinol and febuxostat for adult gout patients that had an assessment of liver function outcomes. Non-English studies on case reports, case series, reviews, and abstracts only were excluded. We extracted information from the studies to answer the research question, ie, study design, publication year, population, sample size, patient characterization, duration, Jadad score, and liver function outcomes.

Results

We screened 512 publications from the databases and identified 11 studies that met the inclusion criteria. Ten out of 11 included studies were double-blind RCTs. In the majority of the included studies, no statistically significant differences were observed in terms of hepatic safety data between febuxostat and allopurinol. However, in studies where allopurinol titration was used, it posed a challenge to maintain blinding. Notably, consistent adverse events related to liver function findings were observed across all reviewed RCTs. These abnormal liver function test results sometimes led to study withdrawal based on the investigators' assessment. Nevertheless, the investigators classified most liver function test elevations as mild to moderate in severity.

Conclusion

Our analysis concluded that adult gout patients enrolled in the included RCTs exhibited similar hepatic safety profiles for both febuxostat and allopurinol treatment. Liver function abnormalities were identified in all RCTs included in this systematic review. Consequently, it is important for the product labeling information of both allopurinol and febuxostat to present and describe the current safety data to guide healthcare practitioners when prescribing these medications to patients. Pharmacovigilance and post-marketing pharmacoepidemiology data are essential in establishing the comprehensive safety profile.

Allopurinol for Secondary Prevention in Patients with Cardiovascular Disease: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

The effects of allopurinol in patients with cardiovascular disease are not well defined; therefore, the latest evidence is summarized in this study.

METHODS

PubMed, Embase, Cochrane Library, and ClinicalTrials.gov databases were searched for randomized controlled trials (RCTs) of allopurinol in patients with cardiovascular disease published up to 11 February 2023. The primary outcome was cardiovascular death.

RESULTS

We combined the results of 21 RCTs that included 22,806 patients. Compared to placebo/usual care, allopurinol treatment was not associated with a significant reduction in cardiovascular death (RR 0.60; 95% CI 0.33-1.11) or all-cause death (RR 0.90; 95% CI 0.72-1.12). However, evidence from earlier trials and studies with small sample sizes indicated that allopurinol might confer a protective effect in decreasing cardiovascular death (RR 0.34; 95% CI 0.15-0.76) across patients undergoing coronary artery bypass grafting (CABG) or having acute coronary syndrome (ACS). In comparisons between allopurinol and febuxostat, we observed no difference in cardiovascular death (RR 0.92; 95% CI 0.69-1.24) or all-cause death (RR 1.02; 95% CI 0.75-1.38).

CONCLUSION

Allopurinol could not reduce cardiovascular (CV) death or major adverse CV outcomes significantly in patients with existing cardiovascular diseases. Given the limitations of the original studies, the potential advantages of allopurinol observed in patients undergoing CABG or presenting with ACS necessitate further confirmation through subsequent RCTs. In the comparisons between allopurinol and febuxostat, our analysis failed to uncover any marked superiority of allopurinol in reducing the risk of adverse cardiovascular incidents.

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 Stiff Joint: Comparative Evaluation of Monotherapy and Combination Therapy With Urate Lowering Agents in Managing Acute Gout

Gout, an extremely painful form of arthritis, is triggered by the innate immune system's response to the accumulation of monosodium urate crystals in specific joints and surrounding tissues. This condition is characterized by recurring episodes of excruciating arthritis flares, interspersed with periods of disease quiescence. Over time, gout can result in disability, tophi formation, and severe pain. The treatment of gout is centered around two main objectives: alleviating inflammation and pain during acute gout attacks and long-term management to reduce serum urate levels and mitigate the risk of future attacks. Addressing inflammation and pain during acute attacks is often complicated by various factors, including underlying health conditions commonly associated with gout, such as hypertension, chronic kidney disease, cardiovascular disease, and diabetes mellitus. Moreover, gout patients are frequently older and have multiple coexisting health issues, necessitating complex medication regimens. Given the rising prevalence of gout and its associated comorbidities, there's a growing demand for improved treatment options. While existing treatments effectively manage gout in some patients, a significant portion, particularly those with comorbidities, face contraindications to these treatments and require alternative approaches. Innovative medications are required to enhance gout treatment, especially for individuals with concurrent health conditions. These considerations underscore the importance of reviewing both monotherapy and combination therapy approaches for acute gout treatment.

Contributing Factors of Diabetes Mellitus among Patients with Gout (Results of the Long-Term Prospective Study)

It is assumed that the risk of developing type 2 diabetes mellitus (T2DM) in patients with gout is influenced by both generally accepted risk factors and factors related to gout. The aim of the study was to evaluate the impact of various risk factors for T2DM in patients with gout. A total of 444 patients (49 women, 395 men) ≥18 years old with gout and without DM were included. The duration of observation was 5.66 [2.69; 7.64] years. To identify the factors associated with the risk of developing T2DM, multivariate logistic regression was used, which included sex; T2DM in relatives; insufficient physical activity; unbalanced diet; age  ≥ 45 years; ≥4 attacks per year; presence of tophi; BMI ≥30 kg/m2; allopurinol, febuxostat, glucocorticoids, diuretics, metformin, colchicine; GFR < 60 mL/min/1.73 m2; serum uric acid level (sUA) ≥ 420 µmol/L and  ≥ 480 µmol/L. T2DM developed in 108 (24.3%) patients. According to the multivariate model, the presence of ≥4 attacks of arthritis per year increased the risk of T2DM (OR = 5.23; 95% CI: 2.98-9.19; p = 0.0001); presence of tophi (OR = 2.61; 95% CI: 1.50-4.54; p = 0.001); sUA ≥ 480 µmol/L (OR = 2.26; 95% CI: 1.02-5.00; p = 0.144); diuretics (OR = 2.35; 95% CI: 1.19-4.64; p = 0.014). Febuxostat (OR = 0.31; 95% CI: 0.11-0.84; p = 0.022) and metformin (OR = 0.49; 95% CI: 0.21-1.16; p = 0.107) reduced the risk of developing T2DM. Risk of T2DM in patients with gout is associated with high incidence of arthritis attacks, MK ≥ 480 μmol/L, hypertension, diuretic use, and febuxostat and metformin reduces risk.

Females present higher dose-adjusted drug concentrations of metoprolol and allopurinol/oxypurinol than males

Females present a higher risk of adverse drug reactions. Sex-related differences in drug concentrations may contribute to these observations but they remain understudied given the underrepresentation of females in clinical trials. The aim of this study was to investigate whether anthropometric and socioeconomic factors and comorbidities could explain sex-related differences in concentrations and dosing for metoprolol and oxypurinol, the active metabolite of allopurinol. We conducted an analysis of two cross-sectional studies. Participants were self-described "White" adults taking metoprolol or allopurinol selected from the Montreal Heart Institute Hospital Cohort. A total of 1007 participants were included in the metoprolol subpopulation and 459 participants in the allopurinol subpopulation; 73% and 86% of the participants from the metoprolol and allopurinol subpopulations were males, respectively. Females presented higher age- and dose-adjusted concentrations of both metoprolol and oxypurinol (both p < 0.03). Accordingly, females presented higher unadjusted and age-adjusted concentration:dose ratio of both metoprolol and allopurinol/oxypurinol compared to males (all p < 3.0 × 10^-4 ). Sex remained an independent predictor of metoprolol concentrations (p < 0.01), but not of oxypurinol concentrations, after adjusting for other predictors. In addition to sex, age, daily dose, use of moderate to strong CYP2D6 inhibitors, weight, and CYP2D6 genotype-inferred phenotype were associated with concentrations of metoprolol (all p < 0.01). Daily dose, weight, estimated glomerular filtration rate (eGFR), and employment status were associated with oxypurinol concentrations (all p < 0.01). Females present higher dose-adjusted concentrations of metoprolol and oxypurinol than males. This suggests the need for sex-specific dosing requirements for these drugs, although this hypothesis should be validated in prospective studies.

A lifetime economic research of universal HLA-B*58:01 genotyping or febuxostat initiation therapy in Chinese gout patients with mild to moderate chronic kidney disease

OBJECTIVE

To evaluate Chinese long-term economic impact of universal human leukocyte antigen B (HLA-B)*58:01 genotyping-guided urate-lowering therapy or febuxostat initiation therapy for gout patients with mild to moderate chronic kidney disease (CKD) from perspective of healthcare system.

METHODS

A Markov model embedded in a decision tree was structured including four mutually exclusive health states (uncontrolled-on-therapy, controlled-on-therapy, uncontrolled-off-therapy, and death). Mainly based on Chinese real-world data, the incremental costs per quality-adjusted life years (QALYs) gained were evaluated from three groups (universal HLA-B*58:01 testing strategy, and no genotyping prior to allopurinol or febuxostat initiation therapy) at 25-year time horizon. All costs were adjusted to 2021 levels based on Chinese Consumer Price Index and were discounted by 5% annually. One-way and probability sensitivity analysis were performed.

RESULTS

Among these three groups, universal HLA-B*58:01 genotyping was the most cost-effective strategy in base-case analysis according to Chinese average willingness-to-pay threshold of $37 654.50 per QALY. The based incremental cost-effectiveness ratio was $31784.55 per QALY, associated with 0.046 additional QALYs and $1463.81 increment costs per patient at a 25-year time horizon compared with no genotyping prior to allopurinol initiation strategy. Sensitivity analysis showed 64.3% robustness of these results.

CONCLUSION

From Chinese perspective of healthcare system, HLA-B*58:01 genotyping strategy was cost-effective for gout patients with mild to moderate CKD in mainland China, especially in the most developed area, such as Beijing and Shanghai. Therefore, we suggest China's health authorities choose the genotyping strategy and make different recommendations according to the differences of local conditions.

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.

Oxyberberrubine, a novel liver microsomes-mediated secondary metabolite of berberine, alleviates hyperuricemic nephropathy in mice

BACKGROUND

Berberrubine (BRB), one of the major metabolites of berberine (BBR), exerts an anti-hyperuricemic effect even superior to BBR. Liver is an important location for drug transformation. Nevertheless, there are few studies on the bioactivities and metabolites of BRB.

PURPOSE

We investigated whether oxyberberrubine (OBR), a liver metabolite of BRB, exerted urate-lowering and reno-protective effects in hyperuricemic mice.

METHODS

Liver microsomes were used to incubate BRB for studying its biotransformation. We isolated and identified its new metabolite OBR, and investigated its anti-hyperuricemic and reno-protective effects. In this work, the hyperuricemic mice model was established by receiving potassium oxonate (PO) and hypoxanthine (HX) for 7 consecutive days. 1 h after modeling, different dosages of OBR (5, 10 and 20 mg/kg), BRB (20 mg/kg) or febuxostat (Fex, 5 mg/kg) were given mice by gavage.

RESULTS

Results showed that OBR possessed potent anti-hyperuricemic and reno-protective effects in hyperuricemic mice. Serum uric acid (UA) level was lowered, and the activities of xanthine oxidase (XOD) as well as adenosine deaminase (ADA) in the liver were suppressed after treatment with OBR. Hepatic expressions of XOD were remarkably decreased at mRNA and protein levels by OBR treatment. In addition, OBR prominently alleviated renal injury, embodied in markedly reduced serum creatinine and blood urea nitrogen (BUN) levels, decreased inflammatory mediators (TNF-α, IL-1β, IL-6 and IL-18) levels, mRNA expression of CYP27B1 and repairment of renal tissues damage. Besides, OBR down-regulated renal expression of urate transporter 1 (URAT1), glucose transporter 9 (GLUT9), NOD-like receptor 3 (NLRP3), apoptosis-associated speck-like protein containing CARD (ASC), and caspase-1 at mRNA and protein levels.

CONCLUSIONS

In short, our study indicated that OBR possessed superior anti-hyperuricemic and reno-protective effects, at least in part, through the inhibition of XOD, URAT1, GLUT9 and NLRP3 inflammasome signaling pathway in the kidney.

Effects of febuxostat on delaying chronic kidney disease progression: a randomized trial in China

BACKGROUND

A few studies have tested febuxostat for its usefulness in delaying chronic kidney disease (CKD) progression by treating hyperuricemia and results were controversial. Thus, we attempted to conduct a randomized controlled study using the Chinese population with advanced grade of CKD.

METHODS

One hundred CKD patients in stages 3 and 4 with asymptomatic hyperuricemia from seven medical centers were included in this prospective randomized controlled study and assigned to the control and febuxostat group, the latter of which received febuxostat to titrate to achieve serum uric acid (SUA) < 6 mg/dL. The observation period was 12 months. The primary outcomes included the event of estimated glomerular filtration rate (eGFR) decline ≥ 30% or 50% from baseline at 12 months, dialysis and death from CKD; secondary outcome was the change in eGFR. Safety analysis was also performed.

RESULTS

Forty-seven patients and 45 patients in the febuxostat and control groups, respectively completed the study. Seven of 47 (14.9%) participants reached 30% decline in eGFR in the febuxostat group, while 1 (2.1%) and 2 (4.3%) patients reached 50% decline in eGFR or dialysis. Thirteen (28.9%), 10 (22.2%) and 3 (6.7%) of 45 patients reached primary kidney outcomes separately in the control group. The change in eGFR after 12 months from baseline in the febuxostat group was 0.50 mL/min/1.73 m², which was significantly higher than that in the control group - 4.46 mL/min/1.73 m² (p = 0.006). Adverse events did not differ between two groups.

CONCLUSIONS

Febuxostat effectively slowed eGFR decline in patients with CKD stages 3 and 4 and asymptomatic hyperuricemia.

Population pharmacokinetic modelling of febuxostat in healthy subjects and people with gout

AIMS

To investigate and characterise the pharmacokinetics of febuxostat and the effect of the covariates of renal function and body size descriptors on the pharmacokinetics of the drug.

METHODS

Blood samples (n = 239) were collected using sparse and rich sampling strategies from healthy (n = 9) and gouty (n = 29) subjects. Febuxostat plasma concentrations were measured by a validated high-performance liquid chromatography method. Population pharmacokinetic analysis was performed using NONMEM. A common variability on bioavailability (FVAR) approach was used to test the effect of fed status on absorption parameters. Covariates were modelled using a power model.

RESULTS

The time course of the plasma concentrations of febuxostat is best described by a two-compartment model. In the final model, the population mean for apparent clearance (CL/F), apparent central volume of distribution (Vc/F), apparent peripheral volume of distribution (Vp/F), absorption rate constant (ka) and apparent intercompartmental clearance (Q/F) were 6.91 l h^-1 , 32.8 l, 19.4 l, 3.6 h^-1 and 1.25 l h^-1 , respectively. The population parmater variability (coefficient of variation) for CL/F, Vc/F and Vp/F were 13.6, 22 and 19.5%, respectively. Food reduced the relative biovailability and ka by 67% and 87%, respectively. Renal function, as assessed by creatinine clearance, was a significant covariate for CL/F while body mass index was a significant covariate for Vc/F.

CONCLUSIONS

Renal function and body mass index were significant covariates. Further work is warranted to investigate the clinical relevance of these results, notably as renal impairment and obesity are common occurrences in people with gout.

A Retrospective Study of the Perioperative Period Management of Joint Arthroplasty in Patients with Chronic Kidney Disease

OBJECTIVE

With the rising prevalence of chronic kidney disease (CKD) and the increasing demand for joint arthroplasty, the management of CKD patients in the perioperative period of joint arthroplasty has become an issue worthy of attention for orthopedic surgeons. This study aimed to explore comprehensive perioperative period management strategies for CKD patients.

METHODS

From March 2017 to August 2022, 62 patients who underwent joint arthroplasty in our hospital were included in a retrospective study, including 31 CKD patients (mean age 69.8 ± 13.4 years old) and 31 non-CKD patients (mean age 69.4 ± 14.2 years old). The outcome indicators were analyzed, including serum urea, serum creatinine, blood uric acid, hematocrit, and hemoglobin.

RESULTS

All patients included in the retrospective study had an average preoperative preparation time of 4.3 ± 2.6 days and an average hospitalization time of 11.0 ± 7.3 days. There were no significant differences in the changes in the serum urea values between the preoperative and postoperative measurements in the CKD patients or in the serum creatinine values and blood uric acid values (P > 0.05). The hemoglobin value in postoperative measurements was lower than in preoperative measurements in the CKD patients (P < 0.05). The hematocrit value in postoperative measurements was lower than in preoperative measurements in the CKD patients (P < 0.001).

CONCLUSION

Patients with CKD have distinct characteristics compared to non-CKD patients, and they generally have a higher risk for postoperative complications and adverse events. Recognition of risk factors, suitable timing of surgery, the undertaking of protective strategies, and proper management of complications are vital for managing CKD patients in the perioperative period of joint arthroplasty.

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.

Febuxostat Therapy for Patients with Gout and Stage 2-4 CKD: a Retrospective Study

Introduction

The aim of this study is to explore the efficacy and renal safety of febuxostat in gout and stage 2–4 chronic kidney disease (CKD) and factors that correlated with target serum urate (SU).

Methods

A single-center retrospective study including male patients with gout and CKD was conducted. SU, the rate of SU < 360 µmol/L (RAT), and renal safety were analyzed in subjects who received febuxostat over 44 weeks. Factors that correlated with target SU were also explored.

Results

Between January 2017 and March 2021, 102 patients (stage 2 CKD: n = 27; stage 3 CKD: n = 70; stage 4 CKD: n = 5) were enrolled. The SU level reduced significantly over 44 weeks (600.76 ± 95.42 versus 405.52 ± 111.93 µmol/L; P < 0.05), and RAT increased to 39.20%. The overall estimated glomerular filtration rate (eGFR) level improved over 44 weeks (52.05 ± 11.68 versus 55.46 ± 14.49 mL/min/1.73 cm², P < 0.05). An obvious improvement of eGFR was observed in stage 3 CKD, in patients with ≤ 1 risk factor (hypertension, diabetic mellitus, hyperlipidemia, or usage of non-steroidal anti-inflammatory drugs), and in patients with terminal SU < 360 µmol/L (P < 0.05). Logistic regression analysis indicated that baseline SU level and body weight were correlated with RAT. Further analysis revealed that patients with SU < 600 μmol/L and body weight ≤ 70 kg reached higher RAT (56.7%).

Conclusions

Febuxostat demonstrated efficacy and renal safety in patients with gout and CKD in clinical practice. Achieving the target SU could obviously improve renal function. Baseline SU level and body weight could affect the achievement of target SU.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40744-022-00480-7.

Traditional Chinese herbs and natural products in hyperuricemia-induced chronic kidney disease

Hyperuricemia is a common biochemical disorder, which resulted from both excessive uric acid (UA) production and/or absolute or relative impairment of urinary UA excretion. Growing evidence has indicated that hyperuricemia is an independent risk factor for the development and progression of chronic kidney disease (CKD), causing hyperuricemia-induced CKD (hyperuricemic nephropathy, HN). The therapeutic strategy of HN is managing hyperuricemia and protecting kidney function. Adverse effects of commercial drugs make persistent treatment of HN challenging. Traditional Chinese medicine (TCM) has exact efficacy in lowering serum UA without serious adverse effects. In addition, TCM is widely applied for the treatment of CKD. This review aimed to provide an overview of efficacy and mechanisms of traditional Chinese herbs and natural products in hyperuricemia-induced CKD.

Hypouricemic effect of 2,4-dihydroxybenzoic acid methyl ester in hyperuricemic mice through inhibiting XOD and down-regulating URAT1

In this paper, we reported the hypouricemic effect of 2,4-dihydroxybenzoic acid methyl ester (DAE), a component of Ganoderma applanatum, in hyperuricemic mice through inhibiting XOD and down-regulating URAT1. Computationally, DAE showed a high similarity to allopurinol and depicted a high affinity in docking to XOD. In vitro, DAE exhibited an inhibitory effect against XOD. Importantly, DAE demonstrated a remarkable hypouricemic effect, decreasing serum uric acids (SUAs) of hyperuricemic mice (407 ± 31 μmol/L) to 195 ± 23, 145 ± 33 and 134 ± 16 μmol/L (P < 0.01) at the doses of 20, 40, and 80 mg/kg with a dose-dependent manner and showing efficacies at 54-68 %, which were close to the efficacies of allopurinol (61 %) and benzbromarone (57 %). DAE depicted higher and negatively dose-independent urinary uric acids in comparison with that of the hyperuricemic control, implying DAE exerted an uricosuric effect and also a reduction effect on uric acid production. Unlike toxic allopurinol and benzbromarone, no general toxicity on body weights and no negative influence on liver, kidney, spleen and thymus were observed for DAE. Mechanistically, DAE inhibited XOD activities in vivo. Moreover, DAE up-regulated OAT1 and down-regulated GLUT9, URAT1 and CNT2. Overall, DAE may present a hypouricemic effect through inhibiting XOD and up-regulating OAT1 and down-regulating GLUT9, URAT1 and CNT2. This work provided novel insights into the hypouricemic effect of DAE and G. applanatum.

Effect modification by contextual factors of urate-lowering therapy on serum urate in people with gout: A systematic review with meta-regression analysis

OBJECTIVE

To synthesize evidence of the effect of contextual factors (CFs) on efficacy of urate-lowering therapy (ULT) on serum urate (SU) as outcome in gout patients.

METHODS

Randomised controlled trials (RCTs) from (updated) Cochrane reviews were the starting point. RCTs were included if they explored the role of any CF on efficacy of ULT on SU in gout patients. For CFs with sufficient data (i.e. ≥3 trials), a mixed-effects meta-regression analysis was performed with trial and comparison as random effects, whereas specific CFs were modelled as fixed factors.

RESULTS

Eight RCTs were included. Effect modification by CFs was explored for age, sex, race, renal function, cardiovascular comorbidity, tophi, thiazide-diuretic use, and previous ULT use. Crude data stratified by renal function were available for four trials (36 randomised comparisons), and suitable for meta-analysis. Pooled estimates revealed that gout patients with a normal, mildly-, or moderately impaired renal function were consistently more likely to achieve SU target with ULT compared to control. Among RCTs comparing ULT to placebo (30 comparisons), effects of ULT on achieving SU target were not statistically different for those with normal (OR:66.87;[11.39-392.75]) compared to mildly (OR:28.54;[5.11-159.46]) and moderately (OR:21.45;[3.20-143.64]) impaired renal function, but seemed lower in those with severely impaired (OR:9.13;[0.96-86.97]) renal function. Data were insufficient to draw conclusions on effect modification by other CFs.

CONCLUSION

Few RCTs report stratified analyses exploring the role of CFs. ULT seemed effective in reaching the SU target in all levels of renal function, though severely impaired renal function appeared to render a slight disadvantage.

Effect of omega-three supplementation on serum urate and gout flares in people with gout; a pilot randomized trial

Objectives

To determine the effect of omega-three supplementation with fish oil on serum urate, weight and body mass index (BMI) in people with gout.

Methods

A pilot 6-month, randomized, open-label clinical trial was undertaken in people with gout with serum urate ≥ 0.36 mmol/l. Forty participants were randomized to receive 6.2 g omega-3 fish oil daily or no fish oil for 24 weeks. Blood was obtained monthly for serum urate and red cell EPA (20:5n-3) DHA (22:6n-3) were measured using a blood spot collection system.

Results

There was no statistically significant difference in the mean (SEM) decrease in serum urate between baseline and week 24 between randomized groups: fish oil − 0.021 (0.02) mmol/l versus control − 0.006 (0.02) mmol/l. There was no significant difference in change in weight or BMI between baseline and week 24 between randomized groups. There was a statistically significant correlation between red cell omega-three concentrations and the total number of flares per participant between week 12 and week 24; total omega-three r =  − 0.75 (p ≤ 0.001), EPA r =  − 0.75 (p ≤ 0.001) and DHA r = -0.76 (p ≤ 0.001). In the omega-three fish oil group four participants reported gastrointestinal adverse effects definitely or probably related to the omega-three supplementation.

Conclusions

The lack of untoward effect of omega three fish oil supplementation on serum urate and BMI together with the relationship between higher omega-three concentrations and lower gout flares supports the development of further adequately powered clinical trials to determine the role of omega-three supplements as prophylaxis against gout flares in people starting urate lowering therapy.

Clinical trial registration ACTRN12617000539336p Registered 13/04/2017.

Increased risk of cardiovascular events and death in the initial phase after discontinuation of febuxostat or allopurinol: another story of the CARES trial

OBJECTIVES

The Cardiovascular Safety of Febuxostat or Allopurinol in Patients with Gout (CARES) trial suggested a higher risk of cardiovascular (CV) death from febuxostat than from allopurinol. However, a significant number of patients died after discontinuation of febuxostat or allopurinol. We investigated whether major adverse cardiovascular events (MACE) and CV death were increased because of discontinuation of febuxostat or allopurinol using the CARES trial data.

METHODS

We compared the MACE that occurred during administration and after discontinuation in the initial phase after discontinuation, and we compared the CV and non-CV mortality rates in the initial phase after discontinuation to determine the impact of discontinuation of febuxostat or allopurinol.

RESULTS

Among 6190 patients, the incidence rate per 100 person-years for MACE was 3.11 during administration and 6.71 after discontinuation. MACE was significantly increased after discontinuation compared with that during administration within 1 month (HR 7.40; 95% CI 5.38 to 10.17) and 6 months (HR 5.22; 95% CI 4.26 to 6.39). In the analysis excluding death induced by adverse events that occurred up to 1 day after the last medication, the CV mortality rate was higher than the non-CV mortality rate within 6 months (45.7% vs 27.9%, p=0.0001). In addition, changes in serum uric acid levels from baseline to the last measurement before discontinuation were significantly associated with higher MACE risk after drug discontinuation (HR 1.14; 95% CI 1.04 to 1.26).

CONCLUSIONS

MACE and CV death were increased in the initial stage after discontinuation of febuxostat or allopurinol in patients with gout.

Efficacy of Xanthine Oxidase Inhibitors in Lowering Serum Uric Acid in Chronic Kidney Disease: A Systematic Review and Meta-Analysis

Objective: Current guidelines for gout recommend a treat-to-target approach with serum uric acid (SUA). However, there is little evidence for the dose-dependent effects of urate-lowering therapy (ULT). Herein, we analyzed the reported SUA-lowering effect and SUA target achievement differences for various doses of xanthine oxidase inhibitors. Methods: Approved ULT drugs were selected from the FDA Drug Database. We included prospective randomized controlled trials of ULT drugs from ClinicalTrials.gov, articles published in the journal “Drugs”, and Embase, a literature database. A meta-analysis was performed to determine the ability of different ULT drugs and doses to lower and maintain a target SUA < 6 mg/dL. Results: We identified 35 trials including 8172 patients with a baseline SUA of 8.92 mg/dL. The allopurinol, febuxostat, and topiroxostat showed dose-proportional SUA-lowering responses. Compared with allopurinol 300 mg daily, febuxostat 80 mg daily and 120 mg daily more effectively maintained SUA < 6 mg/dL. Conclusion: Allopurinol, febuxostat, and topiroxostat showed dose-proportional ability to lower and achieve a target SUA < 6 mg/dL. Significance and Innovations. We showed dose-dependent SUA lowering effects of allopurinol, febuxostat, and topiroxostat. Febuxostat is effective at ULT compared to allopurinol and could be potentially offered as an alternative agent when patients (1) have CKD, (2) have the human leukocyte antigen HLA-B*5801 allele, and (3) become refractory to allopurinol. Gradual allopurinol dose increase with a lower starting dose is needed in CKD.

Managing Gout in Women: Current Perspectives

Gout is a common inflammatory arthritis that tends to affect significantly more men than women. However, female gout patients are more likely to have comorbidities such as hypertension, diabetes mellitus, and renal dysfunction. Furthermore, they experience a greater disease burden due to gout than males. While nonbiological causes may possibly contribute to this sex discrepancy in burden, this raises questions regarding whether current gout pharmacotherapies are as efficacious in females as they are in males. In this review, we examine how the clinical profile of female gout patients differs from male patients; we then survey the literature for data on outcomes for female gout patients treated with urate-lowering therapies for chronic management of gout as well as commonly used agents for acute flares. We also discuss considerations for managing gout in women during pregnancy and lactation.

Comparative Effectiveness of Allopurinol and Febuxostat in Gout Management

BACKGROUND

The relative efficacy and safety of allopurinol and febuxostat when used according to current guidelines for the treatment of hyperuricemia are unknown. This double-blind noninferiority trial examined these issues.

METHODS

Participants with gout and hyperuricemia (with at least 33% having stage 3 chronic kidney disease) were randomly assigned to allopurinol or febuxostat in this 72-week trial, with doses titrated to target serum urate. The trial had three phases: titration (weeks 0 to 24), maintenance (weeks 25 to 48), and observation (weeks 49 to 72). Allopurinol and febuxostat were initiated at daily doses of 100 and 40 mg, with maximum titration to 800 and 120 mg, respectively. Antiinflammatory prophylaxis was given during phases 1 and 2. The primary end point was the proportion of patients experiencing one or more flares during phase 3, with a prespecified noninferiority margin of less than 8 percentage points between allopurinol and febuxostat. Secondary end points included efficacy in patients with chronic kidney disease, proportion achieving target serum urate levels, and serious adverse events.

RESULTS

This study included 940 participants; 20.1% withdrew, with similar proportions in treatment arms. During phase 3, 36.5% of allopurinol-treated participants had one flare or more compared with 43.5% of febuxostat-treated participants (P<0.001 for noninferiority). Overall, 80% of participants achieved mean target urates during phase 2 with no differences by treatment. There were no treatment differences (including cardiovascular events) in serious adverse events.

CONCLUSIONS

Allopurinol and febuxostat achieved serum urate goals in patients with gout; allopurinol was noninferior to febuxostat in controlling flares. Similar outcomes were noted in participants with stage 3 chronic kidney disease. (Funded by the Cooperative Studies Program of the Department of Veterans Affairs Office of Research and Development; ClinicalTrials.gov identifier, NCT02579096.).

U-shaped association of uric acid to overall-cause mortality and its impact on clinical management of hyperuricemia

Serum uric acid (SUA) is significantly elevated in obesity, gout, type 2 diabetes mellitus, and the metabolic syndrome and appears to contribute to the renal, cardiovascular and pulmonary comorbidities that are associated with these disorders. Most previous studies have focused on the pathophysiologic effects of high levels of uric acid (hyperuricemia). More recently, research has also shifted to the impact of hypouricemia, with multiple studies showing the potentially damaging effects that can be caused by abnormally low levels of SUA. Along with these observations, recent inconclusive data from human studies evaluating the treatment of hyperuricemia with xanthine oxidoreductase (XOR) inhibitors have added to the debate about the causal role of UA in human disease processes. SUA, which is largely derived from hepatic degradation of purines, appears to exert both systemic pro-inflammatory effects that contribute to disease and protective antioxidant properties. XOR, which catalyzes the terminal two steps of purine degradation, is the major source of both reactive oxygen species (O2^.-, H₂O₂) and UA. This review will summarize the evidence that both elevated and low SUA may be risk factors for renal, cardiovascular and pulmonary comorbidities. It will also discuss the mechanisms through which modulation of either XOR activity or SUA may contribute to vascular redox hemostasis. We will address future research studies to better account for the differential effects of high versus low SUA in the hope that this will identify new evidence-based approaches for the management of hyperuricemia.

The Role of Advanced Imaging in Gout Management

Gout is a common form of inflammatory arthritis where urate crystals deposit in joints and surrounding tissues. With the high prevalence of gout, the standardized and effective treatment of gout is very important, but the long-term treatment effect of gout is not satisfied because of the poor adherence in patients to the medicines. Recently, advanced imaging modalities, including ultrasonography (US), dual-energy computed tomography (DECT), and magnetic resonance imaging (MRI), attracted more and more attention for their role on gout as intuitive and non-invasive tools for early gout diagnosis and evaluation of therapeutic effect. This review summarized the role of US, DECT, and MRI in the management of gout from four perspectives: hyperuricemia, gout attacks, chronic gout, and gout complications described the scoring systems currently used to quantify disease severity and discussed the challenges and limitations of using these imaging tools to assess response to the gout treatment.

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

Reduced Risk of Sepsis and Related Mortality in Chronic Kidney Disease Patients on Xanthine Oxidase Inhibitors: A National Cohort Study

Background

Advanced chronic kidney disease (CKD) patients are at higher risk of sepsis-related mortality following infection and bacteremia. Interestingly, the urate-lowering febuxostat and allopurinol, both xanthine oxidase inhibitors (XOis), have been suggested to influence the sepsis course in animal studies. In this study, we aim to investigate the relationship between XOis and infection/sepsis risk in pre-dialysis population.

Methods

Pre-dialysis stage 5 CKD patients with gout were identified through the National Health Insurance Research Database (NHIRD) in Taiwan from 2012 to 2016. Outcomes were also compared with national data.

Results

In our nationwide, population-based cohort study, 12,786 eligible pre-dialysis stage 5 CKD patients were enrolled. Compared to non-users, febuxostat users and allopurinol users were associated with reduced sepsis/infection risk [hazard ratio (HR), 0.93; 95% confidence interval (CI), 0.87–0.99; P = 0.0324 vs. HR, 0.92; 95% CI, 0.86–0.99; P = 0.0163]. Significant sepsis/infection-related mortality risk reduction was associated with febuxostat use (HR, 0.68; 95% CI, 0.52–0.87). Subgroup analysis demonstrated preference of febuxostat over allopurinol in sepsis/infection-related mortality among patients younger than 65 years of age, stain users, non-steroidal anti-inflammatory drug non-users, and non-diabetics. There was no significant difference in major adverse cardiac and cerebrovascular event (MACCE) risk between users and non-users while reduced risk of all-cause mortality was observed for XOi users.

Conclusions

Use of XOi in pre-dialysis stage 5 CKD patients may be associated with reduced risk of sepsis/infection and their related mortality without increased MACCE and overall mortality.

Gouty Arthropathy: Review of Clinical Manifestations and Treatment, with Emphasis on Imaging

Gout, a crystalline arthropathy caused by the deposition of monosodium urate crystals in the articular and periarticular soft tissues, is a frequent cause of painful arthropathy. Imaging has an important role in the initial evaluation as well as the treatment and follow up of gouty arthropathy. The imaging findings of gouty arthropathy on radiography, ultrasonography, computed tomography, dual energy computed tomography, and magnetic resonance imaging are described to include findings of the early, acute and chronic phases of gout. These findings include early monosodium urate deposits, osseous erosions, and tophi, which may involve periarticular tissues, tendons, and bursae. Treatment of gout includes non-steroidal anti-inflammatories, colchicine, glucocorticoids, interleukin-1 inhibitors, xanthine oxidase inhibitors, uricosuric drugs, and recombinant uricase. Imaging is critical in monitoring response to therapy; clinical management can be modulated based on imaging findings. This review article describes the current standard of care in imaging and treatment of gouty arthropathy.

Simultaneous determination of febuxostat and montelukast in human plasma using fabric phase sorptive extraction and high performance liquid chromatography-fluorimetric detection

In the present work, a new sensitive and selective high-performance liquid chromatography-fluorimetric detection (HPLC-FLD) method was developed and validated to quantify febuxostat (FBX) and montelukast (MON) in human plasma. The developed procedure was successfully applied to a study aimed at evaluating the pharmacokinetic profiles of febuxostat and montelukast in human plasma. A sol-gel poly (caprolactone)-block-poly(dimethylsiloxane)-block-poly(caprolactone) (sol-gel PCAP-PDMS-PCAP) extraction sorbent coated fabric phase sorptive extraction membrane was used in the extraction process. The entire chromatographic analysis was performed with isocratic elution of the composition of the mobile phase (acetonitrile:water, 60:40, v:v, 0.032% glacial acetic acid) on the C18 column. The flow rate is varied during the analysis, particularly from 0.5 mL min^-1 at the start and linearly increased to 1.5 mL min^-1 in 7 min. The detection and quantification of the analytes was carried out by means of a fluorimetric detector at 320 nm and 350 nm as absorption wavelengths and at 380 and 400 nm as emission wavelengths for FBX and MON, respectively. The calibration curves demonstrated linearity in the range 0.3-10 ng mL^-1 and 5-100 ng mL^-1 for FBX and MON, respectively, while the LOD and LOQ values were 0.1 and 0.3 ng mL^-1 for FBX and 1.5 and 5 ng mL^-1 for MON. Intraday and interday RSD% values were found lower than 5.79%. As reported, the method was applied to real plasma samples obtained from a volunteer who was co-administered both the drugs. Pharmacokinetic data reveal that the concentration of both the drugs reaches the plateau approximately at the same time, but exhibits an elimination phase at different rates. This study demonstrated the usefulness of the new method and its applicability in therapeutic drug monitoring (TDM).

Pharmacotherapy for gout

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

Effect of Berberine on Hyperuricemia and Kidney Injury: A Network Pharmacology Analysis and Experimental Validation in a Mouse Model

Purpose

Berberine (BBR) is an active component of Phellodendri Cortex (PC), which is a traditional Chinese medicine that has been prescribed clinically for hyperuricemia (HUA) for hundreds of years. Many studies reported the anti-inflammatory and nephroprotective properties of BBR and PC; however, the therapeutic effects of BBR on HUA have not been explored. This study aims to investigate the efficacy and mechanism of BBR for treating HUA.

Methods

The mechanism of BBR in the treatment of HUA were predicted by network pharmacology. A mouse model of HUA established by potassium oxonate and hypoxanthine was used to verify the prediction. The levels of serum uric acid (UA), urea nitrogen (BUN) and creatinine (CRE) were determined by biochemical test kits. Hematoxylin and eosin staining of kidney tissues was used to observe the kidney damage. ELISA kits were applied to detect the levels of interleukin (IL)-1β and IL-18 in serum and kidney tissues. Quantitative real-time PCR and Western blotting were adopted to analyze the expression of NLRP3, ASC, Caspase1, IL-1β and URAT1. The expressions of URAT1 in the kidney tubules were visualized by immunohistochemical staining. Molecular docking was used to assess the interaction between URAT1 and BBR.

Results

The network pharmacology screened out 82 genes and several inflammation-related signaling pathways related to the anti-hyperuricemia effect of BBR. In the in vivo experiment, BBR substantially decreased the level of UA, BUN and CRE, and alleviated the kidney damage in mice with HUA. BBR reduced IL-1β and IL-18, and downregulated expressions of NLRP3, ASC, Caspase1 and IL-1β. BBR also inhibited expression of URAT1 and exhibited strong affinity with this target in silico docking.

Conclusion

BBR exerts anti-HUA and nephroprotective effects via inhibiting activation of NLRP3 inflammasome and correcting the aberrant expression of URAT1 in kidney. BBR might be a novel therapeutic agent for treating HUA.

Pegloticase treatment of chronic refractory gout: Update on efficacy and safety

Gout is currently the most frequent cause of inflammatory arthritis worldwide. It results from elevated serum urate and subsequent deposition of monosodium urate crystals in joints and other tissues. While many patients with gout can be managed with conventional agents (e.g., allopurinol, febuxostat), those with chronic refractory gout often fail to achieve treatment goals with these agents. Pegloticase is a recombinant, pegylated mammalian uricase developed for treatment of chronic refractory gout. Pegloticase is different than other urate lowering therapies in that it enzymatically degrades urate. Pegloticase has been evaluated in multiple studies, most importantly in two randomized controlled trials and a follow-up open-label extension. Extensive analysis of results from these studies has shown that pegloticase profoundly lowers serum urate, resolves tophi, reduces tender and swollen joint counts, decreases pain, and improves both patients' global assessments and quality of life. Pegloticase also significantly decreases blood pressure in patients with chronic refractory gout, but has no significant effect on renal function. Post hoc analyses of clinical results also indicated that chronic refractory gout patients not achieving sustained urate lowering still have significant clinical benefits with pegloticase treatment. The major limitation of pegloticase is immunogenicity and the emergence of anti-drug antibodies that result in increased drug clearance, loss of efficacy, and infusion reactions. However, these reactions can be avoided by stopping pegloticase when there is a loss of serum urate lowering. New dosing regimens and co-administration of immunosuppressive agents are also being employed to overcome this limitation and extend the benefits of pegloticase to a larger number of patients.

The association between urate-lowering therapies and treatment-related adverse events, liver damage, and major adverse cardiovascular events (MACE): A network meta-analysis of randomized trials

PURPOSE

Hyperuricemia is a common disease that may lead to gout, renal damage, and cardiovascular events. Oral medication is the main treatment for hyperuricemia patients when lifestyle intervention fails. An evaluation of the safety of various urate-lowering therapies (ULTs) is integral to clinical decision-making. We constructed a network meta-analysis (NMA) to evaluate the safety of oral ULTs.

METHODS

MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched up to April 1, 2021, for randomized controlled trials that examined the safety of ULTs. The language restriction was English. The three outcomes used to assess the safety of uric acid lowering medications were treatment-related adverse events, liver damage, and major adverse cardiovascular events (MACE).

RESULTS

Thirty-two trials enrolling 23,868 individuals were included in the study. In terms of treatment-related adverse events, there were no statistically significant differences between five uric acid lowering medications and placebo: allopurinol (risk ratio (RR): 1.08; 95% credible interval (CrI): 0.91, 1.29), febuxostat (RR: 1.05; 95% CrI: 0.89, 1.25), lesinurad (RR: 1.19; 95% CrI: 0.85, 1.67), lesinurad combined with xanthine oxidase inhibitor (XOI, RR: 1.05; 95% CrI: 0.83, 1.32), and topiroxostat (RR: 1.01; 95% CrI: 0.83, 1.23). Topiroxostat likely increases risk of liver damage (RR: 2.65; 95%CI: 1.24, 5.70; NNH: 33.40) as compared with placebo. With regard to MACE, there were no statistically significant differences between three uric acid lowering medications and placebo: allopurinol (RR: 0.63; 95% CrI: 0.36, 1.34), febuxostat (RR: 0.69; 95% CrI: 0.38, 1.66), and lesinurad combined with XOI (RR: 0.56; 95% CrI: 0.23, 1.85). The rankings of different interventions were depicted by cumulative ranking curve (SUCRA).

CONCLUSIONS

Through NMA, we provide some evidence for the safety of ULTs. We found no statistically significant differences in their effects on treatment-related adverse events and MACE. However, topiroxostat likely increases the risk of liver damage.

Cardiovascular Safety of Febuxostat and Allopurinol in Hyperuricemic Patients With or Without Gout: A Network Meta-Analysis

Background: Hyperuricemia is a common metabolic disease and has become a public health problem because of its increasing prevalence and association with comorbidities. Allopurinol and febuxostat are recommended as the first-line treatments for hyperuricemia and gout. But cardiovascular safety between febuxostat and allopurinol is still controversial. The purpose of this study is to compare the cardiovascular safety of XOIs and placebo in hyperuricemic patients with or without gout. Methods: PubMed, Embase via OVID, Cochrane Library, CNKI, Wanfang, and VIP were searched from their earliest records to February 8th 2021. ClinicalTrials.gov was also searched for unpublished data. The reference lists of included studies and relevant review articles investigating the cardiovascular safety of XOIs in hyperuricemia patients are screened for potentially eligible studies. Randomized controlled trials (RCTs) evaluating allopurinol (100~900 mg/d), febuxostat (20~120 mg/d), or placebo for hyperuricemia were included. The outcomes were incidence of MACE, non-fatal MI, non-fatal stroke, and cardiovascular death. We conducted a Bayesian random-effects network meta-analysis on the included randomized controlled trials using the Markov Chain Monte Carlo simulation method. The grading of recommendations assessment, development, and evaluation (GRADE) approach was used to assesses the certainty of the evidence. Results: Ten RCTs with 18,004 participants were included. The network estimates showed that there was no significant difference observed among febuxostat, allopurinol, and placebo regarding outcomes. The certainty of the evidence ranged from very low to moderate. The probabilities of rankings and SUCRA showed that compared to placebo, febuxostat, and allopurinol might prevent adverse cardiovascular events. Conclusion: Febuxostat is not associated with increasing risk of adverse cardiovascular events compared to allopurinol; and compared to placebo, whether febuxostat and allopurinol reduce the risk of adverse cardiovascular events remains uncertain.