Acute severe liver dysfunction induced by febuxostat in a patient undergoing hemodialysis

Pathology, target discovery, and the evolution of XO inhibitors from the first discovery to recent advances (2020-2023)

Hyperuricemia, a disease characterized by elevation of serum uric acid level beyond 6 mg/dL. This elevation led to appearance of symptoms from joint pain to gout and from gout to difficulty in mobility of the patient. So, in this review, we have summarized the pathology of hyperuricemia, discovery of target and discovery of first XO inhibitor. At last, this review provides in-sights about the recently discovered as natural XO inhibitors, followed by design, structure activity relationship and biological activity of synthetic compounds as XO inhibitors discovered between 2020 and 2023 years. At last, the pharmacophores generated in this study will guide new researchers to design and modify the structure of novel XO inhibitors.

Two cases report of febuxostat-induced acute liver injury: acute heart failure as a probable risk factor?

Drug induced liver injury, as a sub-type of hepatotoxicity, is rare but practical problem, producing challenges for clinicians. Within the recent two months, two patients with heart failure develop febuxostat-induced acute liver injury during hospital stay. To the best of our knowledge, very few cases of febuxostat-induced hepatotoxicity have been reported up to now. In this paper, two unusual cases of febuxostat-induced acute liver injury are herein described. The medical history, drug treatment, clinical symptoms, liver function tests, diagnosis and prognosis are fully given in this paper. It should be noticed that, two liver injury happen in patients of heart failure with reduced ejection fraction. Whether heart failure is a risk factor of febuxostat related liver injury, deserves further research. This paper reminds the clinicians that more attention should be paid to the acute liver injury caused by febuxostat, and liver function tests are suggested especially for patients of heart failure.

Shikonin derivatives as potent xanthine oxidase inhibitors: in-vitro study

Induction of hypersensitivity reactions (may be fatal too) by specific XO inhibitors has led to development of new molecules that are efficacious and have safer ADME profile. Among natural compounds, biologically active Alkannin/Shikonin (A/S) derivatives have unexplored XO inhibition potential. Therefore, their iso-hexenylnaphthazarin nucleus was studied and found that the nucleus is similar to that of allopurinol, signifying the XO inhibitory potential of these derivatives. For confirmation of their potential, β,β-dimethylacrylshikonin and deoxyshikonin were successfully isolated and characterised from Arnebia euchroma (Royle.) Johnst. (Boraginaceae) and were evaluated for in vitro XO inhibitory potential. β,β-dimethylacrylshikonin and deoxyshikonin showed a good XO inhibition potential with IC₅₀ values of 7.475 ± 1.46 µg/mL and 4.487 ± 0.88 µg/mL, respectively. Results also validated the pharmacophore hypothesis, and it was concluded that nucleus iso-hexenylnaphthazarin can be remodelled for optimising the efficacy.

Study of quality markers of antiuric acid formula by grey relational analysis

Gout has become a global problem, antiuric acid formula (AAF) is a clinical prescription highly effective in reducing uric acid levels. In order to find its quality control standards and contribute to the treatment of gout in the future, we adopted high-performance liquid chromatography and orbitrap liquid chromatography–mass spectrometry to establish fingerprints of 13 batches of AAF. The different batches of AAF were tested the activity of inhibit uric acid by the xanthine oxidase inhibition experiment. Grey relational analysis and bio-activity validation to assess the spectrum–effect relationship. Finally, we choose puerarin, calycosin-7-O-beta-d-glucoside and puerarin apioside as the AAF quality control component, and its average content is 6036.006 μg/g, 296.113 μg/g and 878.285 μg/g. As the quality control components of AAF, puerarin, calycosin-7-O-beta-d-glucoside and puerarin apioside can be of great significance for the treatment of gout and gout related research.

Ascites management by cell-free concentrated ascites reinfusion therapy during recovery from drug-induced acute liver injury: a case report

Background

The symptoms of drug-induced hepatic injury are manifold; however, the presence of ascites indicates a severe disease condition. The rapid accumulation of ascites is distressing and requires palliative treatment. Because many cases are addressed by repeated large-volume paracentesis, often resulting in impairment due to protein and electrolyte loss, a different approach is required.

Case presentation

A 61-year-old Japanese man on maintenance dialysis was admitted to our hospital with acute liver injury. Our patient was diagnosed as having drug-induced liver injury due to warfarin or diltiazem, which started immediately after coronary artery bypass grafting 7 months previously. One month after admission, our patient’s hepatic encephalopathy remained grade 1 and his prothrombin time international normalized ratio was maintained at < 1.5. However, the liver was markedly atrophied with massive ascites. Although liver transplantation was desired, he was considered unfit for transplantation because of his renal and cardiac complications. Therefore, we devised a strategy to manage the massive ascites with cell-free concentrated ascites reinfusion therapy while awaiting liver regeneration. At first, cell-free concentrated ascites reinfusion therapy was required frequently because ascites accumulated rapidly. But the fluid retention interval was gradually extended as intended, and cell-free concentrated ascites reinfusion therapy was withdrawn after 8 months. During that time, the size of his liver increased from 1419 cm³ to 1587 cm³ on computed tomography.

Conclusions

Cell-free concentrated ascites reinfusion therapy is an apheresis therapy in which ascites are collected aseptically by paracentesis, concentrated, and then reinfused intravenously. This treatment has the advantage of preserving nutrition by reusing the fluid. Previously, cell-free concentrated ascites reinfusion therapy was used only for the management of ascites in patients with cirrhosis or carcinomatous peritonitis. This case suggests that palliation and maintenance of nutritional status with cell-free concentrated ascites reinfusion therapy may be useful as an adjunct to liver regeneration in drug-induced hepatic injury.

Concomitant febuxostat enhances methotrexate-induced hepatotoxicity by inhibiting breast cancer resistance protein

Methotrexate (MTX) is an antifolate agent used for the treatment of various malignancies and is eliminated by breast cancer resistance protein (BCRP). Because febuxostat (FBX) is known to inhibit BCRP activity, FBX might exacerbate MTX-related adverse effects. In this study, we examined the drug-drug interaction between FBX and MTX in BCRP-expressing membrane vesicles. Moreover, we retrospectively investigated the impact of FBX on MTX-related adverse effects in 38 patients (144 cycles) receiving high-dose MTX therapy (HDMTX). The Food and Drug Administration Adverse Event Reporting System (FAERS) database and human hepatocellular carcinoma cell line HepG2 cells were used to evaluate the effects of FBX on MTX-induced hepatotoxicity. In the membrane vesicle study, FBX significantly inhibited BCRP-mediated transport of MTX. Concomitant FBX significantly increased the incidence of hepatotoxicity, but not of nephrotoxicity and hematological toxicity in patients receiving HDMTX. FAERS database analyses revealed that the reporting odds ratio of FBX for MTX-induced hepatotoxicity was 4.16 (95% CI: 2.89-5.98). Co-incubated FBX significantly decreased the cell viability and increased cytotoxicity in MTX-treated HepG2 cells. These findings suggest that concomitant FBX enhances MTX-induced hepatotoxicity by inhibiting hepatic BCRP. These findings provide important information for the safe management of HDMTX therapy in clinical settings.

Clinical Pharmacokinetics and Pharmacodynamics of Febuxostat

Febuxostat is a xanthine oxidoreductase inhibitor that has been developed to treat chronic gout. In healthy subjects, the pharmacokinetic parameters of febuxostat after multiple oral dose administration include an oral availability of about 85 %, an apparent oral clearance (CL/F) of 10.5 ± 3.4 L/h and an apparent volume of distribution at steady state (V _ss/F) of 48 ± 23 L. The time course of plasma concentrations follows a two-compartment model. The initial half-life (t _½) is approximately 2 h and the terminal t _½ determined at daily doses of 40 mg or more is 9.4 ± 4.9 h. Febuxostat is administered once daily. The maximum (peak) plasma concentrations are approximately 100-fold greater than the trough concentrations. Consequently, there is no significant accumulation of the drug during multiple dose administration. There are few data on the pharmacokinetics of febuxostat in patients with gout. While the pharmacokinetic parameters are not affected by mild to moderate hepatic impairment, there is no consensus on whether renal impairment has any effect on the pharmacokinetics of febuxostat. Febuxostat is extensively metabolised by oxidation (approximately 35 %) and acyl glucuronidation (up to 40 %); febuxostat acyl glucuronides are cleared by the kidney. In healthy subjects treated with multiple doses of febuxostat 10-240 mg, the concentrations of serum urate are reduced by a maximum of about 80 %. The percentage reduction in the concentrations of serum urate is slightly less in gouty patients than in healthy subjects.

A Novel Multi-Epitope Vaccine Based on Urate Transporter 1 Alleviates Streptozotocin-Induced Diabetes by Producing Anti-URAT1 Antibody and an Immunomodulatory Effect in C57BL/6J Mice

Hyperuricemia (HUA) is related to diabetes. Uric acid-induced inflammation and oxidative stress are risk factors for diabetes and its complications. Human urate transporter 1 (URAT1) regulates the renal tubular reabsorption of uric acid. IA-2(5)-P2-1, a potent immunogenic carrier designed by our laboratory, can induce high-titer specific antibodies when it carries a B cell epitope, such as B cell epitopes of DPP4 (Dipeptidyl peptidase-4), xanthine oxidase. In this report, we describe a novel multi-epitope vaccine composing a peptide of URAT1, an anti-diabetic B epitope of insulinoma antigen-2(IA-2) and a Th2 epitope (P2:IPALDSLTPANED) of P277 peptide in human heat shock protein 60 (HSP60). Immunization with the multi-epitope vaccine in streptozotocin-induced diabetes C57BL/6J mice successfully induced specific anti-URAT1 antibody, which inhibited URAT1 action and uric acid reabsorption, and increased pancreatic insulin level with a lower insulitis incidence. Vaccination with U-IA-2(5)-P2-1 (UIP-1) significantly reduced blood glucose and uric acid level, increased Th2 cytokines interleukin (IL)-10 and IL-4, and regulated immune reactions through a balanced Th1/Th2 ratio. These results demonstrate that the URAT1-based multi-epitope peptide vaccine may be a suitable therapeutic approach for diabetes and its complications.