Systemic allopurinol administration reduces malondialdehyde, interleukin 6, tumor necrosis factor α, and increases vascular endothelial growth factor in random flap Wistar rats exposed to nicotine.

INTRODUCTION: Smoking poses a risk to flap viability, with nicotine being a major contributor to the formation of free radicals. Allopurinol, known for its antioxidant properties, has been shown to enhance tissue survival in ischemic conditions by reducing the production of reactive oxygen species (ROS). This study aims to assess the impact of allopurinol on the viability and success of skin flaps in Wistar rats exposed to nicotine. METHODS: This study examined skin flap survival in nicotine-exposed rats treated with allopurinol. Twenty-eight rats were separated into two groups. During 1 month of nicotine exposure, the treatment group received systemic allopurinol 7 days before and 2 days after the flap procedure, while the control group received no allopurinol. Pro-angiogenic factors, proinflammatory factors, anti-inflammatory factors, and oxidative markers were assessed on the 7th day after the flap procedure using enzyme-linked immunosorbent assay method. Macroscopic flap viability was evaluated on the 7th day using Image J photos. RESULTS: As an oxidative marker, malondialdehyde levels were significantly lower in rats given allopurinol than in controls (P < 0.001). The levels of interleukin 6 and tumor necrosis factor α, as markers of inflammatory factors, were significantly lower in the group of rats given allopurinol compared to controls (P < 0.001). The level of angiogenesis in rats given allopurinol, measured by vascular endothelial growth factor levels, was also higher in the treatment group compared to controls (P < 0.001). Macroscopically, the percentage of distal flap necrosis in Wistar rats given allopurinol was lower and statistically significant compared to controls (P < 0.001). CONCLUSIONS: Xanthine oxidoreductase is part of a group of enzymes involved in reactions that produce ROS. Allopurinol, as an effective inhibitor of the xanthine oxidase enzyme, can reduce oxidative stress by decreasing the formation of ROS. This reduction in oxidative stress mitigates the risk of ischemic-reperfusion injury effects and significantly increases the viability of Wistar rat flaps exposed to nicotine.

Efficacy and Safety of Allopurinol on Chronic Kidney Disease Progression: A Systematic Review and Meta-Analysis.

OBJECTIVE: Hyperuricemia is associated with the progression of chronic kidney disease (CKD). Whether urate-lowering treatment with allopurinol can delay disease progression remains controversial. METHODS: Relevant databases were searched. Randomized clinical trials comparing the efficacy and -safety of allopurinol in patients with CKD were selected. The primary outcomes were changes in serum uric acid concentration and estimated glomerular filtration rate (eGFR). Random-effects modeling was used to -calculate the standard mean difference (SMD) with 95% CIs. RESULTS: Four trials enrolling 698 participants were included. All were 2-arm parallel trials with a mean duration follow-up of 22.5 months. Congenital anomalies of the kidney and urinary tract were the most common cause of CKD in children, whereas diabetes was the leading cause of CKD in adults. Allopurinol significantly increased the eGFR compared with control groups (SMD, 2.04; 95% CI, 0.60-3.49; p = 0.005; I2 = 98.23%). Allopurinol led to a significant decrease in serum uric acid concentration compared with the control group (SMD, -5.16; 95% CI, -8.31 to -2.01; p = 0.001; I2 = 98.80%). No significant difference in adverse effects was identified between treatment and control groups. CONCLUSIONS: Allopurinol treatment in patients with CKD and hyperuricemia slows the decline in eGFR as compared with placebo, without risk of increased adverse effects.

Association of rare and common genetic variants in MOCOS with inadequate response to allopurinol.

OBJECTIVES: The minor allele of the common rs2231142 ABCG2 variant predicts inadequate response to allopurinol urate lowering therapy. We hypothesize that additional variants in genes encoding urate transporters and allopurinol-to-oxypurinol metabolic enzymes also predict allopurinol response. METHODS: This study included a subset of participants with gout from the Long-term Allopurinol Safety Study Evaluating Outcomes in Gout Patients, whose whole genome was sequenced (n = 563). Good responders had a 4:1 or 5:1 ratio of good (serum urate (SU) <0.36 mmol/l on allopurinol ≤300 mg/day) to poor (SU ≥ 0.36 mmol/l despite allopurinol >300 mg/day) responses over 5-6 timepoints, while inadequate responders had a 1:4 or 1:5 ratio of good to poor responses. Adherence to allopurinol was determined by pill counts, and for a subgroup (n = 303), by plasma oxypurinol >20µmol/l. Using the sequence kernel association test (SKAT) we estimated the combined effect of rare and common variants in urate secretory (ABCC4, ABCC5, ABCG2, SLC17A1, SLC17A3, SLC22A6, SLC22A8) and reuptake genes (SLC2A9, SLC22A11) and in allopurinol-to-oxypurinol metabolic genes (AOX1, MOCOS, XDH) on allopurinol response. RESULTS: There was an association of rare and common variants in the allopurinol-to-oxypurinol gene group (PSKAT-C = 0.019), and in MOCOS, encoding molybdenum cofactor sulphurase, with allopurinol response (PSKAT-C = 0.011). Evidence for genetic association with allopurinol response in the allopurinol-to-oxypurinol gene group (PSKAT-C = 0.002) and MOCOS (PSKAT-C < 0.001) was stronger when adherence to allopurinol therapy was confirmed by plasma oxypurinol. CONCLUSION: We provide evidence for common and rare genetic variation in MOCOS associating with allopurinol response.

Allopurinol: Clinical Considerations in the Development and Treatment of Stevens-Johnson Syndrome, Toxic Epidermal Necrolysis, and Other Associated Drug Reactions.

Allopurinol lowers urate production through the inhibition of xanthine oxidase. It is oxidatively hydroxylated to oxypurinol and is the most prescribed medication for gout treatment. Although it has a beneficial effect in the treatment of this common disease, like many medications, it is also known for having numerous adverse effects. Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), diseases that exist on a spectrum, are two of the most dangerous adverse effects associated with allopurinol use. These immune-mediated disease processes involve almost every organ system. They are essential to recognize as early as possible, as they could potentially be deadly, requiring cessation of the medication with initial signs of rash or other early manifestations of SJS/TEN. One major consideration in the increased risk of allopurinol-mediated or modulated SJS/TEN is the need to have a lower dose in the setting of renal disease. The purpose of this review is not only to examine the involvement of allopurinol in SJS/TEN but also to provide detailed information about the drug, allopurinol, and general features and characteristics of SJS/TEN and other associated drug reactions.

Controversies and practical management of patients with gout and chronic kidney disease.

Uric acid is a toxin retained with advancing kidney disease. Clinical manifestations of hyperuricemia include gout and systemic inflammation that are associated with increased risk of cardiovascular mortality. As many as one-third of all patients with chronic kidney disease have a history of gout, yet <25% of these patients are effectively treated to target serum urate levels of ≤6 mg/dl. A major reason for ineffective management of gout and hyperuricemia is the complexity in managing these patients, with some medications contraindicated and others requiring special dosing, potential drug interactions, and other factors. Consequently, many nephrologists do not primarily manage gout despite it being a common complication of chronic kidney disease, leaving management to the primary physician or rheumatologist. We believe that kidney specialists should consider gout as a major complication of chronic kidney disease and actively manage it in their patients. Here, we present insights from nephrologists and rheumatologists for a team approach to gout management that includes the nephrologist.

Hyperuricemia - consequences of not initiating therapy. Benefits and drawbacks of treatment.

Hyperuricemia, characterized by elevated levels of uric acid in the body, is associated with several health risks, including gout, urolithiasis and cardiovascular disease. Although treatment options are available, they can lead to hypersensitivity reactions, particularly with allopurinol therapy. This paper provides a comprehensive review of the consequences of hyperuricemia, the need for treatment and the potential adverse effects of allopurinol, illustrated by a case study. The study highlights the importance of careful consideration before initiating therapy, particularly in patients with comorbidities and concomitant medication. It emphasizes the need for vigilant monitoring and individualized treatment approaches to reduce adverse effects. In addition, genetic factors, particularly HLA-B*5801, play an important role in determining susceptibility to allopurinol hypersensitivity reactions. This paper highlights the importance of informed decision making in the management of hyperuricemia to optimize patient outcomes while minimizing the risks associated with treatment.

Mechanism and use strategy of uric acid-lowering drugs on coronary heart disease.

Coronary heart disease (CHD) is a serious cardiovascular illness, for which an elevated uric acid (UA) level presents as a considerable risk factor. This can be treated with UA-lowering drugs such as allopurinol and benzbromarone, which can reduce UA levels by the inhibition of UA production or by promoting its excretion. Such drugs can also be beneficial to CHD in other ways, such as reducing the degree of coronary arteriosclerosis, improving myocardial blood supply and alleviating ventricular remodeling. Different UA-lowering drugs are used in different ways: allopurinol is preferred as a single agent in clinical application, but in absence of the desired response, a combination of drugs such as benzbromarone with ACE inhibitors may be used. Patients must be monitored regularly to adjust the medication regimen. Appropriate use of UA-lowering drugs has great significance for the prevention and treatment of CHD. However, the specific mechanisms of the drugs and individualized drug use need further research. This review article expounds the mechanisms of UA-lowering drugs on CHD and their clinical application strategy, thereby providing a reference for further optimization of treatment.

Use of allopurinol to manage skewed 6-mercaptopurine metabolism in pediatric maintenance acute lymphoblastic leukemia treatment.

BACKGROUND: 6-mercaptopurine is a cornerstone of maintenance therapy for pediatric ALL. Response to 6MP is typically determined by the ANC. Therapeutic ANC range while receiving 6MP is between 500 and 1500/µL. In addition to desired myelosuppression, 6MP is associated with multiple adverse drug effects. Increased doses of 6MP can lead to therapeutic ANC values; however, patients may experience adverse effects before obtaining therapeutic myelosuppression, often deemed "skewed metabolism." Allopurinol may potentially correct skewed 6MP metabolism. PROCEDURE: Pediatric patients with ALL with 6MMP and 6TGN metabolites drawn during maintenance therapy were analyzed for allopurinol use. The primary outcome evaluated the percentage of time spent in therapeutic ANC range before and after allopurinol initiation. In addition, the difference in 6MMP:6TGN ratios before and after allopurinol initiation, incidence of hepatotoxicity, and rates of relapse, were analyzed. RESULTS: Ninety-five patients were included for analysis. Thirty-two (34%) patients received allopurinol. There were no significant differences in baseline demographics between the patients who received allopurinol and those who did not. When comparing ANC values pre- and post-allopurinol initiation, a statistically significant increase in the percentage of time spent in therapeutic range was observed (27% vs. 43%; p = .03). In addition, when comparing metabolite ratios pre- and post-allopurinol initiation, a statistically significant decrease in 6MMP:6TGN metabolite ratio values was observed (86.7 vs. 3.6; p < .0001). CONCLUSIONS: Allopurinol significantly increased the percent time in therapeutic ANC range and can be safely utilized to significantly lower the ratio of 6MMP:6TGN metabolites, alleviating the undesirable side effects of 6MMP, and optimizing the anti-leukemic effects associated with 6TGN.

Stevens-Johnson syndrome associated with pancytopenia: a case report.

Introduction and importance: Stevens-Johnson syndrome (SJS) is a rare and unusual hypersensitivity reaction to certain drugs like allopurinol, commonly used for treating gout. SJS is recognized by extensive necrosis and detachment of skin and mucus membranes. Pancytopenia, characterized by decreased levels of red blood cells, white blood cells and platelets, is an exceedingly rare occurrence in the rare disorder SJS. Case presentation: The authors present a 61-year-old male who exhibited symptoms of fever and rash for 5 days accompanied by pancytopenia and liver injury. Clinical discussion: The abdomen and bilateral lower extremities exhibited several well-defined dusky-colored hyperpigmented macular lesions. Initially, these lesions were small, tender, erythematous, and raised, later transitioning to a dark red. Multiple distinct ulcerations were present on the lips and buccal cavity. Additionally, there was denudation of the skin with bleeding observed between the toes of both legs. The causality was assessed as a definite adverse drug reaction according to the Naranjo and ALDEN algorithm. The patient received treatment consisting of intravenous steroid along with prophylactics antibiotics. The individual's pancytopenia was resolved without requiring any blood cells or plasma or platelet concentrate transfusion. Conclusion: The exact pathophysiology of SJS associated with pancytopenia has not yet been fully elucidated. The authors' study hypothesized that the cause of pancytopenia in SJS could be either the direct cytotoxicity of drugs or immune-mediated damage to the bone marrow cells. Additional studies are necessary to establish the precise pathophysiology of the condition. Moreover, our study also indicates that pancytopenia can resolve in SJS without the need for blood cells or plasma or platelet concentrate transfusion. Once more, further studies are required to establish precise management strategies for managing SJS associated with pancytopenia.

Oxidative stress and plasma ceramides in broiler chickens.

The selection for rapid growth in chickens has rendered meat-type (broiler) chickens susceptible to develop metabolic syndrome and thus inflammation. The sphingolipid ceramide has been linked as a marker of oxidative stress in mammals, however, the relationship between sphingolipid ceramide supply and oxidative stress in broiler chickens has not been investigated. Therefore, we employed a lipidomic approach to investigate the changes in circulating sphingolipid ceramides in context of allopurinol-induced oxidative stress in birds. Day zero hatched chicks (n = 60) were equally divided into six groups; an unsupplemented control, an allopurinol group (25 mg/kg body weight), a conjugated linoleic acid (CLA) group where half of the oil used in the control diet was substituted for a CLA oil mixture, a CLA and an allopurinol group utilizing the same dose of CLA and allopurinol, a berberine (BRB) group consisting of berberine supplementation (200 mg/kg feed), and a BRB and allopurinol group, utilizing the same dose of BRB and allopurinol. Conjugated linoleic acid and berberine were utilized to potentially enhance antioxidant activity and suppress the oxidative stress induced by allopurinol treatment. Body weight, plasma uric acid, nonesterified fatty acids (NEFA) and sphingolipid ceramides were quantified. Allopurinol induced an inflammatory state as measured by a significant reduction in plasma uric acid - an antioxidant in birds as well as a metabolic waste product. Results showed that both total and saturated sphingolipid ceramides declined (p < 0.05) with age in unsupplemented chicks, although plasma ceramides C16:0 and 18:0 increased in concentration over the study period. Simple total and saturated sphingolipid ceremide's were further decreased (p < 0.05) with allopurinol supplementation, however, this may be an indirect consequence of inducing an inflammatory state. Neither CLA or BRB were able to significantly attenuate the decline. The administration of allopurinol specifically targets the liver which in birds, is the primary organ for fatty acids synthesis. For this reason, sphingolipid ceramide production might have been unwittingly affected by the addition of allopurinol.

Effects of Eucommia ulmoides leaf extract on xanthine oxidase and chronic kidney disease induced by adenine in rats.

The aim of this study was to explore the uric acid-lowering effect and renal protective effect of Eucommia ulmoides leaf extract (EULE). The results of xanthine oxidase inhibition assay showed EULE exhibited a high inhibition rate similar to that of allopurinol, with an IC50 value of 1.53 mg/mL. A chronic kidney disease (CKD) model was established in adenine-induced rats to investigate the therapeutic effect of EULE on CKD. The results demonstrated EULE could reduce blood pressure and improve renal index. Additionally, EULE could regulate serum and urine indicators of renal function injury, and restore renal tissue morphology. Mechanistically, EULE was found to downregulate levels of malondialdehyde (MDA), tumour necrosis factor-α (TNF-α), and interleukin-1ß (IL-1ß), while upregulating total antioxidant capacity (T-AOC), thereby alleviating inflammatory response in rats, leading to a reduction in renal damage. the Our findings provide potential applications of EULE as a natural product for the improvement of renal injury.

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.

Critically Appraised Topic on Canine Leishmaniosis: Does Treatment with Antimonials and Allopurinol Have the Same Clinical and Clinicopathological Efficacy as Treatment with Miltefosine and Allopurinol, after One Month of Treatment?

The treatment of canine leishmaniosis commonly involves meglumine antimoniate with allopurinol or miltefosine with allopurinol. This study aims to compare the clinical and clinicopathological efficacy at 28-30 days of conventional dosing regimens for both treatments using the critically appraised topic methodology. A comprehensive search across three databases (PubMed, CAB Abstracts, and Web of Science) from March 2004 to September 2023 yielded 16 relevant articles, encompassing 325 ogs treated with meglumine antimoniate and allopurinol, and 273 dogs treated with miltefosine and allopurinol. The findings indicated a significantly higher rate of complete clinical cure in the group treated with meglumine antimoniate and allopurinol. Most dogs in both groups exhibited improvement in clinicopathological alterations after one month of treatment. No significant difference was observed in the number of dogs that showed a negative Leishmania qPCR between the two groups, one month post-treatment. However, quantitative serology results were not commonly reported in the available data and therefore this aspect could not be compared.

Assessment of Bitterness in Non-Charged Pharmaceuticals with a Taste Sensor: A Study on Substances with Xanthine Scaffold and Allopurinol.

Taste sensors with an allostery approach have been studied to detect non-charged bitter substances, such as xanthine derivatives, used in foods (e.g., caffeine) or pharmaceuticals (e.g., etofylline). In this study, the authors modified a taste sensor with 3-bromo-2,6-dihydroxybenzoic acid and used it in conjunction with sensory tests to assess the bitterness of non-charged pharmaceuticals with xanthine scaffolds (i.e., acefylline and doxofylline), as well as allopurinol, an analogue of hypoxanthine. The results show that the sensor was able to differentiate between different levels of sample bitterness. For instance, when assessing a 30 mM sample solution, the sensor response to acefylline was 34.24 mV, which corresponded to the highest level of bitterness (τ = 3.50), while the response to allopurinol was lowest at 2.72 mV, corresponding to relatively weaker bitterness (τ = 0.50). Additionally, this study extended the application of the sensor to detect pentoxifylline, an active pharmaceutical ingredient in pediatric medicines. These results underscore the taste sensor's value as an additional tool for early-stage assessment and prediction of bitterness in non-charged pharmaceuticals.

Tophaceous gout.

Hyperuricemic patients (≥7.8 mg/dL) can develop polyarticular tophaceous gout from intermittent arthritis if untreated. Acute flares and tophi development can be avoided by lowering blood urate levels with xanthine oxidase inhibitors.

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

RATIONALE & OBJECTIVE: We conducted a prespecified examination of the efficacy and safety of allopurinol and febuxostat administered using a treat-to-target strategy in trial participants with chronic kidney disease (CKD). STUDY DESIGN: Prespecified subcohort analysis of a randomized controlled trial. SETTING & PARTICIPANTS: A substudy of the STOP Gout Trial in participants with CKD. CKD was defined as an estimated glomerular filtration rate (eGFR) 30-59mL/min/1.73m2 at baseline. EXPOSURE: Trial participants with CKD and gout and serum urate (SUA) concentration of≥6.8mg/dL were randomized 1:1 to receive allopurinol or febuxostat. Urate-lowering therapy (ULT) was titrated during weeks 0-24 to achieve a goal SUA of<6.0mg/dL (<5.0mg/dL with tophi) (phase 1) and maintained during weeks 25-48 (phase 2). Gout flare was assessed between weeks 49-72 (phase 3). OUTCOME: Gout flare between weeks 49-72 (phase 3) was the primary outcome. Secondary outcomes included SUA goal achievement and ULT dosing at end of phase 2, and serious adverse events. ANALYTICAL APPROACH: Outcomes between treatment groups were compared using logistic regression models for binary outcomes, and Poisson regression for flare rates. Multivariable models were subsequently used, adjusting for factors identified to be imbalanced by treatment arm. RESULTS: CKD was present in 351 of 940 participants; 277 were assessed for the primary outcome. Fewer patients randomized to allopurinol had a flare during phase 3 (32% vs 45%; P=0.02) despite similar attainment of the SUA goal (79% vs 81%; P=0.6) by the end of phase 2. Acute kidney injury was more common in participants with stage 3 CKD randomized to allopurinol compared with febuxostat. LIMITATIONS: Limited power to assess infrequent safety events, largely male, older population. CONCLUSIONS: Allopurinol and febuxostat are similarly efficacious and well-tolerated in the treatment of gout in people with CKD when used in a treat-to-target regimen with lower incidence of gout flares in participants randomized to allopurinol. PLAIN-LANGUAGE SUMMARY: The STOP Gout Trial was a multicenter, randomized, double-blind, noninferiority, comparative effectiveness trial, which found that allopurinol was noninferior to febuxostat in gout flare prevention and that both medications were similarly efficacious in reaching a serum urate goal when used as part of a treat-to-target approach. A significant proportion of patients with chronic kidney disease (CKD) are afflicted by gout, yet there is a lack of high-quality comparative effectiveness data comparing allopurinol and febuxostat in these patients. We evaluated the efficacy and safety of allopurinol and febuxostat in the subgroup of STOP Gout Trial participants with stage 3 CKD and found that allopurinol and febuxostat are similarly efficacious and well-tolerated in the treatment of gout in people with CKD when used in a treat-to-target regimen, with lower incidence of gout flares in participants randomized to allopurinol.

Association between urate-lowering therapy initiation and all-cause mortality in patients with type 2 diabetes and asymptomatic hyperuricemia.

AIMS: To assess the relationships between urate-lowering therapy (ULT) initiation with all-cause mortality in patients with asymptomatic hyperuricemia and Type 2 Diabetes (T2D). METHODS: This nationwide retrospective cohort study involved patients with T2D and asymptomatic hyperuricemia from 19 academic hospitals across China between 2000 and 2021. The primary exposure was ULT initiation, including allopurinol, febuxostat, or benzbromarone. The primary outcome was all-cause mortality. The secondary outcomes were cardiovascular (CV) and non-CV mortality. Propensity score matching was employed to create a 1:2 matched cohort with balanced likelihood of ULT initiation. Associations between ULT initiation with all-cause and CV mortality were assessed in the matched cohort. RESULTS: Among 42 507 patients, 5028 initiated ULT and 37 479 did not. In the matched cohort, comprising 4871 ULT initiators and 9047 noninitiators, ULT initiation was significantly associated with reduced risk of all-cause mortality (hazard ratio [HR] 0.77; 95% confidence interval [CI], 0.71-0.84), CV mortality (HR 0.86; 95% CI, 0.76-0.97), and non-CV mortality (HR 0.72; 95% CI, 0.64-0.80) over an average 3.0 years of follow-up. Among the ULT initiators, post-treatment SUA levels of 360-420 µmol/L was related to a significantly lower risk for all-cause mortality compared to levels >420 µmol/L (HR 0.74; 95% CI, 0.59-0.94) while levels ≤360 µmol/L did not (HR, 0.96; 95% CI, 0.81-1.14), suggesting a U-shaped relationship. CONCLUSIONS: Initiating ULT was associated with a significant reduction in all-cause mortality in patients with T2D and asymptomatic hyperuricemia. Notably, maintaining post-treatment SUA concentrations within 360-420 µmol/L could potentially enhance this reduced mortality.

Risk of urolithiasis associated with allopurinol versus benzbromarone among patients with gout: a population-based cohort study.

OBJECTIVES: To compare the risk of urolithiasis in gout patients initiating allopurinol, a xanthine oxidase inhibitor, vs benzbromarone, a uricosuric. METHODS: Using the 2011-20 Korea National Health Insurance Service database, we conducted a cohort study on gout patients initiating allopurinol vs benzbromarone as the first-line urate-lowering treatment. The primary outcome was a new onset urinary stone. The secondary outcome was a stone requiring intervention. We estimated hazard ratios (HRs) and 95% CIs using Cox proportional hazard models with a 5:1 ratio propensity-score matching on >80 variables. Subgroup analyses were done by age, sex, thiazide use and cardiovascular risk. RESULTS: 61 300 allopurinol initiators PS-matched on 12 260 benzbromarone initiators were included (mean age 59 years, 79% male). During a mean follow-up of 322 days, 619 urolithiasis cases occurred with an incidence rate of 0.87 per 100 person-years in allopurinol and 1.39 in benzbromarone initiators, showing a HR of 0.64 (95% CI, 0.51-0.80). Approximately 44% of urinary stones required intervention with a HR of 0.61 (95% CI, 0.43-0.88). The lower risk associated with allopurinol compared with benzbromarone persisted across subgroups but was greater in the high than non-high cardiovascular risk subgroup (P for interaction = 0.02). CONCLUSION: This population-based cohort study found that allopurinol compared with benzbromarone was associated with a substantially lower risk of urolithiasis particularly in the presence of the high cardiovascular risk. This finding provides important safety information for clinicians' decision-making on urate-lowering treatments of different mechanisms of action.

Management of hypertension addressing hyperuricaemia: introduction of nano-based approaches.

Uric acid (UA) levels in blood serum have been associated with hypertension, indicating a potential causal relationship between high serum UA levels and the progression of hypertension. Therefore, the reduction of serum UA level is considered a potential strategy for lowering and mitigating blood pressure. If an individual is at risk of developing or already manifesting elevated blood pressure, this intervention could be an integral part of a comprehensive treatment plan. By addressing hyperuricaemia, practitioners may subsidize the optimization of blood pressure regulation, which illustrates the importance of addressing UA levels as a valuable strategy within the broader context of hypertension management. In this analysis, we outlined the operational principles of effective xanthine oxidase inhibitors for the treatment of hyperuricaemia and hypertension, along with an exploration of the contribution of nanotechnology to this field.

Understanding the impact of ABCG2 polymorphisms on drug pharmacokinetics: focus on rosuvastatin and allopurinol.

INTRODUCTION: In addition to the well-established understanding of the pharmacogenetics of drug-metabolizing enzymes, there is growing data on the effects of genetic variation in drug transporters, particularly ATP-binding cassette (ABC) transporters. However, the evidence that these genetic variants can be used to predict drug effects and to adjust individual dosing to avoid adverse events is still limited. AREAS COVERED: This review presents a summary of the current literature from the PubMed database as of February 2024 regarding the impact of genetic variants on ABCG2 function and their relevance to the clinical use of the HMG-CoA reductase inhibitor rosuvastatin and the xanthine oxidase inhibitor allopurinol. EXPERT OPINION: Although there are pharmacogenetic guidelines for the ABCG2 missense variant Q141K, there is still some conflicting data regarding the clinical benefits of these recommendations. Some caution appears to be warranted in homozygous ABCG2 Q141K carriers when rosuvastatin is administered at higher doses and such information is already included in the drug label. The benefit of dose adaption to lower possible side effects needs to be evaluated in prospective clinical studies.