Population pharmacokinetic analysis of febuxostat with high focus on absorption kinetics and food effect.

Febuxostat is commonly used in clinic for the treatment of hyperuricemia. Multiple-peak phenomenon has been observed in human plasma concentration-time profiles of febuxostat, but has not been paid enough attention in previous research. This study takes a pivotal step forward by conducting a comprehensive population pharmacokinetic (PopPK) analysis of febuxostat in a healthy Chinese cohort, with a central focus on delineating its absorption profile under contrasting fasting and fed conditions, while concurrently assessing the influence of food alongside other potential covariates on febuxostat's PK profile. The plasma concentration data used for modeling was obtained from two bioequivalence (BE) studies. Subjects were administered febuxostat 20 mg or 80 mg under fasting or fed condition. Goodness-of-fit plots, visual predict check (VPC), and normalized prediction distribution error (NPDE) were used for model evaluation. Based on the established model, PK profiles in healthy Caucasian subjects were simulated with parameter adjustment for race difference on clearance and bioavailability. Data from 128 subjects were used in the PopPK analysis. Febuxostat concentration-time curves were described by a two-compartment model with two deposit absorption compartments and lag times (Tlag). Prandial states (Food) showed significant impact on absorption rate ka1 and ka2, as well as Tlag1, and body weight was identified as a significant covariate on the apparent distribution volume. The PopPK analysis of febuxostat in healthy Chinese volunteers, under both fasted and fed conditions, successfully characterized its PK profile and underscored the significant influence of food on absorption. The potential difference of absorption between Chinese population and Caucasian population indicated from the simulations needs further investigation.

Urate lowering therapy in patients starting hemodialysis limit gout flares occurrence: ten years retrospective study.

BACKGROUND: Uncontrolled gout can cause articular impairment but is also associated with a global and cardiovascular excess mortality, especially in dialysis population. Data documented within existing research is not conclusive regarding gout flares evolution during hemodialysis and their control by urate lowering therapy (ULT). Without clear guidelines concerning hemodialysis patients management with chronic gout, this study proposes to investigate whether gout flare incidence reduction could be observed on this population treated by urate lowering therapy versus patients without treatment. METHODS: We performed a retrospective cohort study in two hemodialysis centers in France. Were selected patients over 18 years old with a gout history who started hemodialysis between January 2005 and September 2015. Demographics and clinicals data were recorded at hemodialysis start and throughout 5 years of follow up. Gout flare was defined as presence of uric acid crystal in joint punction or clinically diagnosed as such with a colchicine prescription. All statistical analysis were performed in SAS® version 9.4 (SAS Institute Inc., Cary, NC). RESULTS: One hundred eighty-one patients have been included, mean age at dialysis initiation was 68.6 years (± 12.4) with 72% of men, 54% were treated by ULT: 89.7% by allopurinol and 9.3% by febuxostat. One patient received both treatments successively. After hemodialysis initiation, 35.36% patients had experienced at least one gout flare. The appearance of at least one gout flare concerned 50% of patients in no ULT group and 22.68% patients in ULT group (p = 0.0002). Dialysis efficiency was measured at regular interval during follow-up and was similar in both groups. To study the association strength between clinical factors and gout flares occurrences, a Cox model was performed; ULT is a protector factor of gout flare (HR:0,42, CI 95: 0,25-0,71). The proportion of serum urate values within the target (median 53% vs 29.3%, p < 0.0001) was significantly higher in ULT group versus no ULT group (median 53% vs 29.3%, p < 0.0001). CONCLUSION: Urate lowering therapy limit new gout flares occurrence in hemodialysis patients with gout historyCollaboration between rheumatologists and nephrologists may help to update guidelines for urate-lowering therapies in patients on dialysis.

Discovery of a Potent and Orally Bioavailable Xanthine Oxidase/Urate Transporter 1 Dual Inhibitor as a Potential Treatment for Hyperuricemia and Gout.

The main uric acid-lowering agents in clinical use for hyperuricemia and gout are xanthine oxidase (XO) inhibitors or urate transporter 1 (URAT1) inhibitors. While these therapies can partially control the disease, they have various limitations. The development of XO/URAT1 dual inhibitors offers the potential to enhance therapeutic potency and reduce toxicity compared with single-target inhibitors. Through scaffold hopping from the XO inhibitor febuxostat (2) and the URAT1 inhibitor probenecid (3), followed by structure-activity relationship (SAR) studies, we identified compound 27 as a potent dual inhibitor of XO and URAT1. Compound 27 demonstrated significant dual inhibition in vitro (XO IC50 = 35 nM; URAT1 IC50 = 31 nM) and exhibited favorable pharmacology and pharmacokinetic (PK) profiles in multiple species including monkeys. Furthermore, toxicity studies in rats and monkeys revealed general safety profiles, supporting that compound 27 emerges as a promising novel drug candidate with potent XO/URAT1 dual inhibition for the treatment of gout.

Spinal Gout: An Unusual Cause of Low Back Pain.

Low back pain is the most common musculoskeletal complaint accounting for over 30 million visits to primary care physicians annually. Serious pathology is found in less than 1% of these visits. Therefore it is often a challenge to distinguish worrisome findings requiring further workup and treatment from common complaints of pain. Gout is an inflammatory arthritis that most commonly affects the appendicular skeleton. It is characterized by the saturation of uric acid and deposition of monosodium urate crystals in joints and tissues. Spinal involvement is rare and is not typically considered on the differential diagnosis for a patient presenting with acute low back pain. We present such a case of a 35-year-old male who presented with intractable back pain, highlighting the need to recognize signs and symptoms that raise suspicion for spinal gout.

Synthesis and Biological Evaluation of Novel Chlorogenic Acid-Apigenin Conjugates as Anti-acute Gout Agents.

Gout is the second largest metabolic disease worldwide after diabetes, with acute gouty arthritis as most common symptom. Xanthine oxidase (XOD) and the NOD like receptor-3 (NLRP3) inflammasome are the key targets for acute gout treatment. Chlorogenic acid has been reported with a good anti-inflammatory activity, and Apigenin showed an excellent potential in XOD inhibition. Therefore, a series of chlorogenic acid-apigenin (CA) conjugates with varying linkers were designed and synthesized as dual XOD/NLRP3 inhibitors, and their activities both in XOD and NLRP3 inhibition were evaluated. An in vitro study of XOD inhibitory activity revealed that the majority of CA conjugates exhibited favorable XOD inhibitory activity. Particularly, the effects of compounds 10c and 10d, with an alkyl linker on the apigenin moiety, were stronger than that of allopurinol. The selected CA conjugates also demonstrated a favorable anti-inflammatory activity in RAW264.7 cells. Furthermore, compound 10d, which showed the optimal activity both in XOD inhibition and anti-inflammatory, was chosen and its inhibitory ability on NLRP3 and related proinflammatory cytokines was further tested. Compound 10d effectively reduced NLRP3 expression and the secretion of interluekin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α) with an activity stronger than the positive control isoliquiritigenin (ISL). Based on these findings, compound 10d exhibits dual XOD/NLRP3 inhibitory activity and, therefore, the therapeutic effects on acute gout is worthy of further study.

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 Maori 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 Maori 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.

Exercise and hyperuricemia: an opinion article.

Hyperuricaemia (HUA) is an abnormally high concentration of serum urate caused by either an excess of uric acid production or decreased excretion capacity in the body. Serum urate concentration forms sodium salts that deposit in the soft tissues of the joints, ultimately leading to gout. Additionally, HUA is strongly associated with several acute and chronic illnesses. In various clinical guidelines and practices, xanthine oxidase inhibitors, such as allopurinol and febuxostat, are commonly used as the initial medication for treating HUA. However, extended usage of urate-lowering drugs may have risks, including cardiovascular thrombotic events and hepatic impairment. Implementing a scientifically informed fitness diet in conjunction with appropriate exercise may decrease HUA. Unfortunately, there is currently a shortfall in exercise intervention trials for individuals suffering from HUA. Most of the previous evidence suggesting that exercise improves serum urate levels comes from intervention trials in other populations, and serum urate is only one of the outcomes observed. This opinion article analyses the causes of HUA, offers dietary and exercise guidance with the aim of furnishing a point of reference for individuals with HUA or fitness enthusiasts.

Psychometric evaluation of the Adherence to Refills and Medications Scale (ARMS) in Australians living with gout.

This study aimed to examine psychometric properties of the Adherence to Refills and Medications Scale (ARMS) in people with gout. We conducted exploratory factor analysis (EFA) and tested internal consistency (ordinal and Cronbach's alpha coefficients) and agreement (intraclass correlation coefficient (2,1)) in ARMS scores across three timepoints (baseline, 6, and 12 months) in 487 people with gout. The Kruskal-Wallis test, Spearman's rank, Kendall's tau-b correlations, and logistic regression were used to examine the criterion-related validity of the ARMS and factors associated with the ARMS. EFA suggested a one-factor structure, explaining 43.2% of total variance. High internal consistency (ordinal alpha = 0.902 at baseline) and moderate agreement in ARMS scores over time (ICCs > 0.5; p < 0.001) were observed. Lower ARMS scores (indicating better adherence) predicted achieving target serum urate (OR, 0.89; 95% CI, 0.83-0.95; p < 0.001), but not urate-lowering therapy (ULT) adherence (Proportion of Days Covered (PDC) ≥ 80%) (OR, 0.93; 95% CI, 0.81-1.05; p = 0.261). Negative correlations between ARMS and PDC were not statistically significant (Kendall's tau-b, r = - 0.126, p = 0.078; Spearman's rho = - 0.173, p < 0.073). Differences in median ARMS scores (IQR) of 16 (14-20), 13 (12-15), and 17.5 (15-21) in three groups of participants who reported (1) not taking ULT, (2) taking ULT and adherent, and (3) taking ULT but not adherent, respectively, were statistically significant (p < 0.001). Age was the only patient factor independently associated with optimal adherence (ARMS score = 12) (OR, 1.91; 95% CI, 1.50-2.43; p < 0.001). The ARMS is a reliable and valid measure of medication adherence behaviours in people with gout, justifying its use in gout medication adherence research.

Gout: A Rapid Review of Presentation, Diagnosis and Management.

Gout is inflammatory arthritis caused by monosodium urate crystal deposition in articular and non-articular structures. Acute gout flares are often monoarticular/polyarticular involving lower extremity joints characteristically involving 1st metatarsophalangeal joint. However, gout flares can also be polyarticular, involving upper extremity joints, especially in patients with multiple comorbidities and contraindications to urate-lowering therapies (ULT). Risk factors exacerbating gout flares include obesity, high alcohol and purine-rich food consumption, and the use of diuretics. Diagnosis requires synovial fluid analysis with direct visualization of monosodium urate crystals. Acute flares are managed with steroids, non-steroidal anti-inflammatory drugs, or colchicine. Long-term management includes lifestyle modifications including a heavy emphasis on weight loss, avoidance of alcohol, purine-rich foods, and diuretics. ULT is indicated in patients with 2 or more gout flares/year, tophi, or radiographic evidence of gouty arthropathy. Although allopurinol is the first-line ULT agent, it does carry a risk of inducing severe cutaneous adverse reactions, especially in patients with chronic kidney disease and patients harboring the HLA-B*5801 allele. Other ULT agents include febuxostat and probenecid. ULT is usually titrated to achieve goal serum uric acid (SUA) levels below 6 mg/dL. However, in patients with tophi, a lower SUA target of less than 5 mg/dL should be implemented for prompt urate crystal dissolution.

Effects of Xanthine Oxidase Inhibition by Febuxostat on Lipid Profiles of Patients with Hyperuricemia: Insights from Randomized PRIZE Study.

Although patients with hyperuricemia and gout often have dyslipidemia, the effects of febuxostat, a xanthine oxidase inhibitor, on their lipid profiles are unclear. Thus, we performed a sub-analysis of the randomized PRIZE study in which the effects of febuxostat on carotid atherosclerosis were investigated in patients with hyperuricemia. The participants were randomized to the febuxostat or control group. The primary endpoint of this sub-analysis was changes in the patients' non-high-density lipoprotein cholesterol (HDL-C) levels from baseline to 6-month follow-up. Correlations between the changes in lipid profiles and cardiometabolic parameters were also evaluated. In total, 456 patients were included. From baseline to 6 months, non-HDL-C levels were significantly reduced in the febuxostat group (-5.9 mg/dL, 95% confidence interval [CI]: -9.1 to -2.8 mg/dL, p < 0.001), but not in the control group (-1.3 mg/dL, 95% CI: -4.4 to 1.8, p = 0.348). The reduction in non-HDL-C levels was more pronounced in women and correlated with changes in serum uric acid and estimated glomerular filtration rate levels only in the febuxostat group. In patients with hyperuricemia, febuxostat treatment was associated with reduced non-HDL-C levels from baseline to the 6-month follow-up compared to the control treatment, suggesting that the lipid-lowering effect of febuxostat should be considered when targeting dyslipidemia.

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.