Therapeutic advances in gout

Design, characterization and comparison of transdermal delivery of colchicine via borneol-chemically-modified and borneol-physically-modified ethosome

Gout is a kind of joint disease characterized by the accumulation of monosodium urate (MSU) crystals in the joint and its surrounding tissue, causing persistent hyperuricemia. Colchicine is the first choice of treatment for acute gout attacks. Due to strong toxicity of colchicines oral tablets, there are high fluctuations of blood drug concentration and serious irritation of gastrointestinal tract, and hence a transdermal preparation can help to slow down the blood drug concentration, reduce the frequency of drug taking, and improve the patients' compliance of the drug. The ethosome is a lipid carrier with high concentration of ethanol and has been proved to promote the penetration of drugs into the skin. Borneol (BO) is an excellent penetration enhancer in Chinese medicine, which can promote the entry of drugs into the skin. This paper prepared the borneol-physically-modified colchicine ethosome (COL-bpES) and used the prepared borneol-dioleoyl phosphoethanloamine (BO-DOPE) to prepare borneol-chemically-modified colchicine ethosome (COL-bcES). Compared to the free colchicine aqueous solution (free COL) and normal colchicine ethosome (COL-ES), the borneol-modified colchicine ethosome (COL-bES) demonstrated better drug penetration effect, while the particle size of the COL-bcES was lower than that of the COL-bpES. Toxicity, in vitro diffusion, pharmacokinetics and pharmacodynamics are superior to those of COL-bpES, providing a better delivery system for the treatment of small molecule inflammatory drugs.

Prophylaxis of acute flares when initiating febuxostat for chronic gouty arthritis in a real-world clinical setting

OBJECTIVE

Flare prophylaxis is recommended during urate-lowering therapy (ULT) despite lack of proven benefit especially when initiating febuxostat. We investigated if colchicine or steroids administration during initiation of febuxostat for chronic gouty arthritis reduces the frequency and/or severity of acute gout flares.

METHODS

Patients with confirmed diagnosis of gout starting febuxostat were retrospectively studied. Frequency, severity, and length of flares were analyzed. Assessment of severity based on a visual analog scale (VAS).

RESULTS

Two hundred and seventy-three patients were studied. The mean dose of colchicine and steroids was 0.53 ± 0.15 mg PO QD and 7.55 ± 1.30 mg prednisone equivalent PO QD; while the duration was 6.13 ± 1.14 and 6.20 ± 1.36 months, respectively. Subjects treated with colchicine and steroids suffered fewer total flares (0.30, 0.96 vs 2.47, p = .000), fewer flares from 0 to 3 months (0.26, 0.71 vs 1.72, p = .000), less severe flares assessed by VAS than those without prophylactic therapy (3.65, 3.49 vs 5.54, p = .000). Both total flares (p = .003) and flares from 0 to 3 months (p = .008) of the colchicine group were fewer than the steroids group. There were no significant differences in length of flares among groups (p = .815). Both colchicine and steroids were well tolerated.

CONCLUSION

The use of colchicine or steroids prophylaxis reduces the frequency and severity of acute gout flares during initiation of febuxostat for chronic gouty arthritis. Colchicine is superior to steroids in flares prophylaxis. Prophylactic therapy with colchicine 0.5 mg PO QD or steroids 7.5 mg prednisone equivalent PO QD for 6 months is suggested.

Gout tophus on an intradural fascicle: a case description

STUDY DESIGN

Case report and review of literature.

OBJECTIVE

Detailed description of case and review of literature to determine its uniqueness with special regard to intradural gout tophus formation without any boney attachment or underlying systemic gout. Gout tophi commonly involve the peripheral joints of the upper and lower extremities. Rarely, gout tophi are located within the spinal cord, especially without any underlying hyperuricemia.

METHODS

We report the case of a 64-year-old patient presenting with radiculopathy along the right L2-dermatome and bladder dysfunction and review literature for further discussion.

RESULTS

Imaging studies showed a partly calcified round intradural lesion at the level L2 without contrast enhancement. The lesion was removed via a hemilaminectomy L2. It was adherent to a dorsal sensory fascicle exiting with the L2 nerve root. The neuropathological examination showed a gout tophus. Serologic testing revealed no signs of hyperuricemia.

CONCLUSION

To the best of our knowledge, this is the first report of a gout tophus originating from an intradural fascicle and without any boney attachment or underlying systemic gout. The literature is reviewed and possible pathophysiological mechanisms are discussed.

A Randomized, Controlled Trial to Assess the Efficacy of Arthroscopic Debridement in Combination with Oral Medication Versus Oral Medication in Patients with Gouty Knee Arthritis

Gouty knee arthritis refers to a form of inflammatory diseases caused by deposits of needle-like crystals of uric acid in knee joint. The aim of this study was to assess the efficacy and safety of arthroscopic debridement in combination with oral medication versus oral medication alone for the treatment of gouty knee arthritis. A total of 60 patients with gouty knee arthritis were randomized to receive either arthroscopic surgery in combination with oral medication or oral medication alone. Efficacy was assessed with the angle of motion, functions, and visual analog scale (VAS). These indices were measured prior to treatment and at 2, 4, 12, 24, and 48 weeks posttreatment. Surgery- and medication-related complications were observed. Significant differences in flexion and extension of the knee joint, lymphoma scores, and VAS were detected between the two groups at 2, 4, and 12 weeks posttreatment (P < 0.05) but not at weeks 24 and 48 posttreatment (P > 0.05) . Significant differences in these indices were detected at different time points in each group (P < 0.05), except between weeks 24 and 48 (P > 0.05). Arthroscopic surgery in combination with oral medication is superior to single oral medication in the flexion and extension of the knee joint, lymphoma scores, and pain relief (VAS) before 24 weeks, although no statistical differences were detected in the efficacy after 24 weeks, and in medication-related safety between the two groups. Although arthroscopic debridement cannot replace systemic uric acid-lowering treatments such as medication and dietary control, it is still an effective approach.

Multinational evidence-based recommendations for the diagnosis and management of gout: integrating systematic literature review and expert opinion of a broad panel of rheumatologists in the 3e initiative

We aimed to develop evidence-based multinational recommendations for the diagnosis and management of gout. Using a formal voting process, a panel of 78 international rheumatologists developed 10 key clinical questions pertinent to the diagnosis and management of gout. Each question was investigated with a systematic literature review. Medline, Embase, Cochrane CENTRAL and abstracts from 2010-2011 European League Against Rheumatism and American College of Rheumatology meetings were searched in each review. Relevant studies were independently reviewed by two individuals for data extraction and synthesis and risk of bias assessment. Using this evidence, rheumatologists from 14 countries (Europe, South America and Australasia) developed national recommendations. After rounds of discussion and voting, multinational recommendations were formulated. Each recommendation was graded according to the level of evidence. Agreement and potential impact on clinical practice were assessed. Combining evidence and clinical expertise, 10 recommendations were produced. One recommendation referred to the diagnosis of gout, two referred to cardiovascular and renal comorbidities, six focused on different aspects of the management of gout (including drug treatment and monitoring), and the last recommendation referred to the management of asymptomatic hyperuricaemia. The level of agreement with the recommendations ranged from 8.1 to 9.2 (mean 8.7) on a 1-10 scale, with 10 representing full agreement. Ten recommendations on the diagnosis and management of gout were established. They are evidence-based and supported by a large panel of rheumatologists from 14 countries, enhancing their utility in clinical practice.

Drug discovery for hyperuricemia

Hyperuricemia is associated with an increased risk of developing gout. This increases with the degree and duration of hyperuricemia. Gout can be managed by dietary modification and pharmacologic urate-lowering therapies. The recent identification of the renal apical urate/anion exchanger URAT1 (SLC22A12) and several membrane proteins relevant to the transport of urate play an important role in gaining a better understanding of the mode of action of many drugs used to treat gout. As described in this review, therapeutics designed to modify URAT1 transport activities might be useful in treating pathologies associated with hyperuricemia such as gout and urolithiasis. Continuing studies into the urate transportsome hold promise for the development of new, more effective therapeutics for hyperuricemia.

Preparation and Comparative Bioavailability Studies of Indomethacin-Loaded Cetyl Alcohol Microspheres

The purpose of the present study was to compare the in vitro release and to find out whether the bioavailability of a 75 mg indomethacin capsule (Microcid SR) was equivalent to optimized formulation (indomethacin-loaded cetyl alcohol microspheres). Indomethacin-loaded cetyl alcohol microspheres were prepared by meltable emulsified cooling-induced technique. Surface morphology of microspheres has been evaluated using scanning electron microscopy. A single dose, randomized, complete cross over study of IM microspheres was carried out on 10 healthy male and female Albino sheep's under fasting conditions. The plasma was separated and the concentrations of the drug were determined by HPLC-UV method. Plasma indomethacin concentrations and other pharmacokinetic parameters obtained were statistically analyzed. The SEM images revealed the spherical shape of fat microspheres, and more than 98.0% of the isolated microspheres were in the size range 12–32 μm. DSC, FTIR spectroscopy and stability studies indicated that the drug after encapsulation with fat microspheres was stable and compatible. Both formulations were found to be bioequivalent as evidenced by in vivo studies. Based on this study, it can be concluded that cetyl alcohol microspheres and Microcid SR capsule are bioequivalent in terms of the rate and extent of absorption.

Gout diagnosis and management: what NPs need to know

Gout is the result of hyperuricemia, from either the body's overproduction or underexcretion. It can result in joint deterioration and destruction when improperly managed. Because primary care providers diagnose and treat the vast majority of patients with gout, it is important that they understand current guidelines and evidence-based practice.

Canakinumab relieves symptoms of acute flares and improves health-related quality of life in patients with difficult-to-treat Gouty Arthritis by suppressing inflammation: results of a randomized, dose-ranging study

INTRODUCTION

We report the impact of canakinumab, a fully human anti-interleukin-1β monoclonal antibody, on inflammation and health-related quality of life (HRQoL) in patients with difficult-to-treat Gouty Arthritis.

METHODS

In this eight-week, single-blind, double-dummy, dose-ranging study, patients with acute Gouty Arthritis flares who were unresponsive or intolerant to--or had contraindications for--non-steroidal anti-inflammatory drugs and/or colchicine were randomized to receive a single subcutaneous dose of canakinumab (10, 25, 50, 90, or 150 mg) (N = 143) or an intramuscular dose of triamcinolone acetonide 40 mg (N = 57). Patients assessed pain using a Likert scale, physicians assessed clinical signs of joint inflammation, and HRQoL was measured using the 36-item Short-Form Health Survey (SF-36) (acute version).

RESULTS

At baseline, 98% of patients were suffering from moderate-to-extreme pain. The percentage of patients with no or mild pain was numerically greater in most canakinumab groups compared with triamcinolone acetonide from 24 to 72 hours post-dose; the difference was statistically significant for canakinumab 150 mg at these time points (P < 0.05). Treatment with canakinumab 150 mg was associated with statistically significant lower Likert scores for tenderness (odds ratio (OR), 3.2; 95% confidence interval (CI), 1.27 to 7.89; P = 0.014) and swelling (OR, 2.7; 95% CI, 1.09 to 6.50, P = 0.032) at 72 hours compared with triamcinolone acetonide. Median C-reactive protein and serum amyloid A levels were normalized by seven days post-dose in most canakinumab groups, but remained elevated in the triamcinolone acetonide group. Improvements in physical health were observed at seven days post-dose in all treatment groups; increases in scores were highest for canakinumab 150 mg. In this group, the mean SF-36 physical component summary score increased by 12.0 points from baseline to 48.3 at seven days post-dose. SF-36 scores for physical functioning and bodily pain for the canakinumab 150 mg group approached those for the US general population by seven days post-dose and reached norm values by eight weeks post-dose.

CONCLUSIONS

Canakinumab 150 mg provided significantly greater and more rapid reduction in pain and signs and symptoms of inflammation compared with triamcinolone acetonide 40 mg. Improvements in HRQoL were seen in both treatment groups with a faster onset with canakinumab 150 mg compared with triamcinolone acetonide 40 mg.

TRIAL REGISTRATION

clinicaltrials.gov: NCT00798369.

Urate-lowering therapy for gout: focus on febuxostat

Gout is a common, painful, and often debilitating rheumatologic disorder that remains one of the few arthritic conditions that can be diagnosed with certainty and cured with appropriate therapy. Allopurinol is the most frequently prescribed agent for gout in the United States. Unfortunately, most patients treated with allopurinol do not achieve target serum uric acid (sUA) levels, possibly due to a perceived intolerability to allopurinol in doses above 300 mg and the need for reduced doses in patients with renal insufficiency. Febuxostat, an orally administered, nonpurine inhibitor of xanthine oxidase, was recently approved by the U.S. Food and Drug administration for chronic management of hyperuricemia in patients with gout. Patients treated with febuxostat achieve rapid and substantial reductions in sUA levels. Compared with allopurinol-treated patients, patients receiving febuxostat 80 mg/day were more likely to achieve sUA concentrations less than 6 mg/dl. In long-term studies (up to 5 yrs), febuxostat demonstrated sustained reductions in sUA levels, nearly complete elimination of gout flares, and a frequency of adverse effects comparable to allopurinol. The most commonly reported adverse effects were liver function abnormalities, rash, nausea, and arthralgias. The recommended starting dose of febuxostat is 40 mg/day, which may be increased to 80 mg/day after 2 weeks if patients do not achieve sUA levels less than 6 mg/dl. Dosage adjustment in mild-to-moderate renal insufficiency is unnecessary; however, data are lacking on the safety of febuxostat in patients with severe renal impairment. Although more costly than allopurinol, febuxostat appears to be an acceptable alternative for the treatment of gout and hyperuricemia, and may be advantageous in patients with renal impairment, intolerance to allopurinol, or the inability to attain sUA levels less than 6 mg/dl despite adequate therapy with available agents.

Preparation, evaluation and bioavailability studies of indomethacin-bees wax microspheres

The present study envisages the preparation of microspheres containing indomethacin (IM) as model drug and bees wax as carrier, and to compare the in vitro release and pharmacokinetics of prepared IM formulation with commercially available oral formulation MicrocidSR. The microsphere formulations were prepared by meltable emulsified dispersion and cooling induced solidification. Surface morphology of microspheres has been evaluated using scanning electron microscopy (SEM). The SEM images revealed the spherical shape of microspheres and more than 98.0% of the isolated microspheres were in the size range 115-855 mum. Differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy studies indicated that the drug after encapsulation with bees wax was stable and compatible. A single dose randomized complete cross over study of IM (75 mg) microspheres was carried out on 8 healthy Albino sheeps. Plasma IM concentrations and other pharmacokinetic parameters obtained were statistically analyzed. The T (max), C (max), AUC(O-24) and T (1/2) values of MicrocidSR and optimized formulation were 3.0 h, 2038 +/- 51.31 ng/ml, 9528 +/- 129.65 ng/ml h(-1), and 2.59 +/- 0.02 h(-1); and 3.2 h, 1940 +/- 22.61 ng/ml, 8751 +/- 41.32 ng/ml h(-1), and 2.68 +/- 0.02 h(-1), respectively. Beeswax microspheres showed controlled release and it can be concluded that both the prepared formulation and MicrocidSR are bioequivalent.

Effects of febuxostat versus allopurinol and placebo in reducing serum urate in subjects with hyperuricemia and gout: a 28-week, phase III, randomized, double-blind, parallel-group trial

OBJECTIVE

To compare the urate-lowering efficacy and safety of febuxostat, allopurinol, and placebo in a large group of subjects with hyperuricemia and gout, including persons with impaired renal function.

METHODS

Subjects (n = 1,072) with hyperuricemia (serum urate level > or = 8.0 mg/dl) and gout with normal or impaired (serum creatinine level >1.5 to < or = 2.0 mg/dl) renal function were randomized to receive once-daily febuxostat (80 mg, 120 mg, or 240 mg), allopurinol (300 or 100 mg, based on renal function), or placebo for 28 weeks.

RESULTS

Significantly (P < or = 0.05) higher percentages of subjects treated with febuxostat 80 mg (48%), 120 mg (65%), and 240 mg (69%) attained the primary end point of last 3 monthly serum urate levels <6.0 mg/dl compared with allopurinol (22%) and placebo (0%). A significantly (P < 0.05) higher percentage of subjects with impaired renal function treated with febuxostat 80 mg (4 [44%] of 9), 120 mg (5 [45%] of 11), and 240 mg (3 [60%] of 5) achieved the primary end point compared with those treated with 100 mg of allopurinol (0 [0%] of 10). Proportions of subjects experiencing any adverse event or serious adverse event were similar across groups, although diarrhea and dizziness were more frequent in the febuxostat 240 mg group. The primary reasons for withdrawal were similar across groups except for gout flares, which were more frequent with febuxostat than with allopurinol.

CONCLUSION

At all doses studied, febuxostat more effectively lowered and maintained serum urate levels <6.0 mg/dl than did allopurinol (300 or 100 mg) or placebo in subjects with hyperuricemia and gout, including those with mild to moderately impaired renal function.

Asymptomatic hyperuricemia: impact of ultrasonography

Thirty-five patients (23 males) with asymptomatic hyperuricemia for at least two years underwent two-dimensional ultrasonography of knees and ankles. Urate deposits (tophi) in tendons, synovium, and other soft tissues were detected in 12 patients (34%). Increased vascularity (inflammation) was evident in 8 of these patients (23%). Tophi were more frequently found in knees than in ankles and were especially prevalent in the distal patellar tendon. The presence of tophi was unrelated to the known duration of hyperuricemia (mean, 5 years). Ultrasonography allows detection of tophi and inflammation in a third and in a fourth, respectively, of asymptomatic hyperuricemic patients.

Utilization of allopurinol in the Australian community

BACKGROUND

International data suggest that suboptimal use of allopurinol is common. Allopurinol dose should be lower in renal impairment, but higher when gout is not controlled. The aim of the study was to examine trends in the usage of allopurinol in the Australian community.

METHODS

Community dispensing data on the urate-lowering drugs allopurinol and probenecid were obtained from databases kept by Medicare Australia and the Drug Utilization Sub-Committee, for January 1992 to December 2005.

RESULTS

Allopurinol comprised 98.4% of all prescriptions for urate-lowering drugs dispensed during 2005. Most prescriptions were for allopurinol 300 mg, but there was a steady shift towards use of allopurinol 100 mg in all states and territories over the period of the study. There were marked variations in prescribing rates across the country. New South Wales had the highest rate of subsidized prescribing for allopurinol 300 mg (39.3 per 1000 population). Tasmania had the highest rate for allopurinol 100 mg (14.3 per 1000 population), which coincided with an educational programme to decrease allopurinol dose in patients with renal impairment. Prescribing rates in the Northern Territory were substantially lower than all other regions, at 10.8 and 3.3 prescriptions per 1000 population for allopurinol 300 and 100 mg, respectively.

CONCLUSION

The increased uptake of allopurinol 100 mg suggests greater adherence to dosing guidelines and that there is value in educational programmes to optimize drug usage. Variability in utilization rates across regions indicates the need for research on factors responsible. Precise understanding of dosing trends requires access to deidentified, individual dosing data.

Why is gout so poorly managed?

See linked article, p1309

Crystal-induced neutrophil activation. IX. Syk-dependent activation of class Ia phosphatidylinositol 3-kinase

The deposition of monosodium urate (MSU) crystals in the joints of humans leads to an extremely acute, inflammatory reaction, commonly known as gout, characterized by a massive infiltration of neutrophils. Direct interactions of MSU crystals with human neutrophils and inflammatory mediators are crucial to the induction and perpetuation of gout attacks. The intracellular signaling events initiated by the physical interaction between MSU crystals and neutrophils depend on the activation of specific tyrosine kinases (Src and Syk, in particular). In addition, PI-3Ks may be involved. The present study investigates the involvement of the PI-3K family in the mediation of the responses of human neutrophils to MSU crystals. The results obtained indicate that the interaction of MSU crystals with human neutrophils leads to the stimulation of class Ia PI-3Ks by a mechanism that is dependent on the tyrosine kinase Syk. We also found an increase in the amount of p85 associated with the Nonidet P-40-insoluble fraction derived from MSU crystal-stimulated human neutrophils. Furthermore, MSU crystals induce the formation of a complex containing p85 and Syk, which is mediated by the Src family kinases. Finally, evidence is also obtained indicating that the activation of PI-3Ks by MSU crystals is a critical element regulating phospholipase D activation and degranulation of human neutrophils. The latter response is likely to be involved in the joint and tissue damage that occurs in gouty patients.