Allopurinol hepatotoxicity

Gout: An old disease in new perspective - A review

Gout is a picturesque presentation of uric acid disturbance. It is the most well understood and described type of arthritis. Its epidemiology is studied. New insights into the pathophysiology of hyperuricemia and gouty arthritis; acute and chronic allow for an even better understanding of the disease. The role of genetic predisposition is becoming more evident. The clinical picture of gout is divided into asymptomatic hyperuricemia, acute gouty arthritis, intercritical period, and chronic tophaceous gout. Diagnosis is based on laboratory and radiological features. The gold standard of diagnosis is identification of characteristic MSU crystals in the synovial fluid using polarized light microscopy. Imaging modalities include conventional radiography, ultrasonography, conventional CT, Dual-Energy CT, Magnetic Resonance Imaging, nuclear scintigraphy, and positron emission tomography. There is remarkable progress in the application of ultrasonography and Dual-Energy CT which is bound to influence the diagnosis, staging, follow-up, and clinical research in the field. Management of gout includes management of flares, chronic gout and prevention of flares, as well as management of comorbidities. Newer drugs in the pharmacological armamentarium are proving successful and supplement older ones. Other important points in its management include patient education, diet and life style changes, as well as cessation of hyperuricemic drugs.

Gout and risk of non-alcoholic fatty liver disease

OBJECTIVES

To investigate the association between gout and non-alcoholic fatty liver disease (NAFLD).

METHODS

The study subjects were participants in a health-screening programme at Chang Gung Memorial Hospital from 2000 to 2006. Subjects were classified into eight groups based on serum urate (SU) level and gout status (≤ 4.9, 5.0-6.9, 7.0-8.9, and ≥ 9.0 mg/dL, without and with gout). The association between gout and NAFLD was assessed by multiple logistic regression.

RESULTS

Among a total of 54 325 subjects, 1930 (3.6%) had gout and 6169 (11.3%) had NAFLD. The prevalence of NAFLD was significantly higher in subjects with gout (23.1%, n = 445) than in those without gout (10.9%, n = 5724, p < 0.001). Among subjects with NAFLD, the severity of NAFLD was higher in gout patients. Gout was associated with an increased risk for NAFLD [odds ratio (OR) 1.42, 95% confidence interval (CI) 1.25-1.60, p < 0.001], after adjustment for age, sex, presence of metabolic syndrome, and low estimated glomerular filtration rate (eGFR). With SU ≤ 4.9 mg/dL in the absence of gout as reference, the ORs (95% CI) for NAFLD, after adjustment for age, sex, presence of metabolic syndrome, and low eGFR, were, respectively, 2.16 (1.94-2.41), 3.98 (3.55-4.46), and 5.99 (5.19-6.90) for SU levels 2-4 in those without gout and 2.61 (1.39-4.91), 2.87 (2.04-4.04), 4.53 (3.70-5.56), and 6.31 (5.12-7.77) for SU levels 1-4 in those with gout.

CONCLUSIONS

There was an independent association between gout and the risk for NAFLD. In addition, there was a dose-response relationship between SU and NAFLD in subjects with and without gout.

Effect of hexacosanol on the characteristics of novel sustained-release allopurinol solid lipospheres (SLS): factorial design application and product evaluation

This investigation involved the evaluation of the effect of hexacosanol (HC, ceryl alcohol), a new hydrophobic wax modifier (WM) in comparison with conventional modifiers, on the development of sustained-release allopurinol (AP) solid lipospheres (SLS) intended for use in a suspension formulation and other oral dosage forms. Various beeswax (BW)/WM blends (composition ratio 1:1) were thus used to prepare SLS by a modified oil-in-water emulsion meltable disperse-phase (MDP) encapsulation method without using organic solvents and the influence of these blends on the drug encapsulation efficiency (EE), size distribution and the time for 50% of the drug to be released (t50%) was investigated. Results indicated that incorporation of HC in wall matrix of SLS provided the means to enhance the EE of AP and to modulate the rate of drug release into dissolution media (simulated gastric fluid (S.G.F.: pH 1.2) and simulated intestinal fluid (S.I.F.: pH 7.4). The effects of the process variables; HC concentration, dispersant (pluronic F-68: PF-68) concentration and drug:wax ratio were also studied on the properties of AP-loaded SLS by a 2(3) factorial design. The EE values were in the range of 80.8-92.67%. The only significant parameter affecting (P<0.01) the size and size distribution of the SLS formulations was the amount of the PF-68, whereas the factor with the biggest influence (P<0.05) on the drug EE was the initial loading of AP (in terms of the drug:wax ratio). The amount of HC blended with wax and the initial drug loading significantly (P<0.01) affected the t50% values of all of the formulations. The release of AP was more extended (t50% values (S.I.F.; pH 7.4)=9.91-25.36 h, depending on the drug:wax ratio) and surface morphology of SLS was improved with higher HC content (15%, w/w) formulations. The release patterns fitted the Baker-Lonsdale dissolution kinetics for spherical matrices. A significant decrease of plasma uric acid levels (P<0.05) and hepatic impairment in male rats was observed after oral administration of a SLS (mean size: 120 microm) suspensions of the optimum formulation, compared to suspensions of pure AP.