Colchicine for the treatment of gout

Synthesis and Biological Evaluation of Colchicine─Aryl/Alkyl Amine Hybrids as Potential Noncytotoxic Cholinesterase Inhibitors: Identification of SBN-284 as a Dual Inhibitor of Cholinesterases and NLRP3 Inflammasome

Colchicine, one of the oldest anti-inflammatory natural products still used clinically, inhibits NF-κB signaling and NLRP3 inflammasome activation. Despite its cytotoxicity and narrow therapeutic range, colchicine continues to intrigue medicinal chemists exploring its anti-inflammatory potential. This study aimed to investigate the colchicine scaffold for its role in Alzheimer's disease by targeting neuroinflammation and cholinesterases. Molecular docking revealed that colchicine's hydrophobic trimethoxyphenyl framework can potentially bind to the peripheral anionic site of cholinesterases. Hybrid structures combining colchicine with aryl/alkyl amines were designed to bind both peripheral and catalytic sites of cholinesterases. We describe here the design, synthesis, and in vitro cytotoxicity evaluation of these colchicine-aryl/alkyl amine hybrids, along with their in silico interactions with the cholinesterase active site gorge. Nontoxic analogs demonstrating strong cholinesterase binding affinity were further evaluated for their anticholinesterase and antineuroinflammatory activities. The colchicine-donepezil hybrid, SBN-284 (3x), inhibited both acetylcholinesterase and butyrylcholinesterase as well as the NLRP3 inflammasome complex at low micromolar concentrations. It achieved this through noncompetitive inhibition, occupying the active site gorge and interacting with both peripheral and catalytic anionic sites of cholinesterases. Analog 3x was shown to cross the blood-brain barrier and exhibited no toxicity to neuronal cells, primary macrophages, or epithelial fR2 cells. These findings highlight the potential of this lead compound for further preclinical investigation as a promising anti-Alzheimer agent.

Salicylic acid modulates secondary metabolism and enhanced colchicine accumulation in long yellow daylily (Hemerocallis citrina)

Salicylic acid (SA) is an essential phytoregulator that is widely used to promote the synthesis of high-value nutraceuticals in plants. However, its application in daylily, an ornamental plant highly valued in traditional Chinese medicine, has not been reported. Herein, we investigated the exogenous SA-induced physiological, transcriptional and biochemical changes in long yellow daylily (LYD). We found that 2 mg/L foliar SA treatment significantly improved LYD plant growth and yield. Transcriptome sequencing and differentially expressed genes (DEGs) analysis revealed that the phenylpropanoid biosynthesis, isoquinoline alkaloid biosynthesis, sulfur metabolism, plant hormone signal transduction and tyrosine metabolism were significantly induced in SA-treated leaves. Many transcription factors and antioxidant system-related DEGs were induced under the SA treatment. Biochemical analyses showed that the leaf contents of soluble sugar, soluble protein (Cpr), ascorbic acid (AsA) and colchicine were significantly increased by 15.15% (from 30.16 ± 1.301 to 34.73 ± 0.861 mg/g), 19.54% (from 60.3 ± 2.227 to 72.08 ± 1.617 mg/g), 30.45% (from 190.1 ± 4.56 to 247.98 ± 11.652 μg/g) and 73.05% (from 3.08 ± 0.157 to 5.33 ± 0.462 μg/g), respectively, under the SA treatment. Furthermore, we identified 15 potential candidate genes for enhancing the growth, production and phytochemical content of LYD. Our results provide support for the bioaccumulation of colchicine in yellow daylily and valuable resources for biotechnological-assisted production of this important nutraceutical in Hemerocallis spp.

Synthesis, Modeling, and Biological Evaluation of Anti-Tubulin Indole-Substituted Furanones

Due to the central role of tubulin in various cellular functions, it is a validated target for anti-cancer therapeutics. However, many of the current tubulin inhibitors are derived from complex natural products and suffer from multidrug resistance, low solubility, toxicity issues, and/or the lack of multi-cancer efficacy. As such, there is a continued need for the discovery and development of new anti-tubulin drugs to enter the pipeline. Herein we report on a group of indole-substituted furanones that were prepared and tested for anti-cancer activity. Molecular docking studies showed positive correlations between favorable binding in the colchicine binding site (CBS) of tubulin and anti-proliferative activity, and the most potent compound was found to inhibit tubulin polymerization. These compounds represent a promising new structural motif in the search for small heterocyclic CBS cancer inhibitors.

Role and Mechanisms of Phytochemicals in Hair Growth and Health

Hair health is associated with personal distress and psychological well-being. Even though hair loss (alopecia) does not affect humans' biological health, it affects an individual's social well-being. So, treatment for hair problems and improving hair health are obligatory. Several pharmacological and cosmeceutical treatment procedures are available to manage hair loss and promote growth. Several factors associated with hair health include genetics, disease or disorder, drugs, lifestyle, chemical exposure, and unhealthy habits such as smoking, diet, and stress. Synthetic and chemical formulations have side effects, so people are moving towards natural compounds-based remedies for their hair problems. The history of using phytochemicals for hair health has been documented anciently. However, scientific studies on hair loss have accelerated in recent decades. The current review summarizes the type of alopecia, the factor affecting hair health, alopecia treatments, phytochemicals' role in managing hair loss, and the mechanisms of hair growth-stimulating properties of phytochemicals. The literature survey suggested that phytochemicals are potent candidates for developing treatment procedures for different hair problems. Further detailed studies are needed to bring the scientific evidence to market.

Efficacy and safety of colchicine for the treatment of osteoarthritis: a systematic review and meta-analysis of intervention trials

OBJECTIVE

Colchicine, an approved treatment for gout, has been trialed in many diseases including osteoarthritis (OA) due to its anti-inflammatory effects. However, its efficacy and safety remain unclear in OA. This systematic review and meta-analysis evaluated the efficacy and safety of colchicine for the treatment of OA.

METHODS

PubMed, Web of Science, Scopus, and Cochrane Central were searched from inception through September 2022. Two reviewers independently screened for randomized controlled trials (RCTs) comparing colchicine with placebo or other active comparators for the treatment of OA (knee, hand, or hip OA), extracted data, and performed Cochrane risk of bias assessments.

RESULT

Nine RCTs for the knee OA and one for the hand OA were identified, consisting of 847 patients (429 in colchicine arms, 409 in control arms). The studies were conducted between 2002 and 2021 with follow-up periods ranging from 2 to 12 months, in India, Iran, Turkey, Australia, Singapore, and Iraq. Moderate-quality evidence showed no clinically important pain reduction with colchicine compared to control (standardized mean difference [SMD], 0.17; 95% confidence interval [CI], - 0.55, 0.22). Moderate-quality evidence showed no improvement in function with colchicine compared to control in knee OA patients (SMD, - 0.37; 95% CI, - 0.87, 0.13). Colchicine showed an acceptable safety profile with AEs/SAEs comparable to control.

CONCLUSION

Current evidence does not suggest a benefit of colchicine in reducing pain and improving physical function in the overall cohort of hand/knee OA patients. Future trials should focus on the subgroups of OA patients with local or systemic inflammation and/or mineralization who might benefit from colchicine.

The use of colchicine as an anti-inflammatory agent for stroke prevention in patients with coronary artery disease: a systematic review and meta-analysis

OBJECTIVE

The primary objective is to evaluate the use of colchicine as an anti-inflammatory agent for stroke prevention in patients with coronary artery disease.

BACKGROUND

There has been a rising number of randomized controlled trials conducted in patients with coronary artery disease on the use of colchicine in reducing cardiovascular complications. Recent publications suggest colchicine reduces the risk of stroke and other cardiovascular events.

METHODS

We performed a systematic review of known trials in the current literature to characterize the clinical characteristics and outcomes of colchicine treatment in patients with coronary artery disease. A literature search was performed in PubMed, Embase and SCOPUS using a suitable keyword search strategy from inception to 4 June 2021. All studies evaluating cardiovascular outcomes of colchicine treatment in patients with coronary artery disease were included.

RESULTS

The systemic review included 5 randomized controlled trials assessing a total of 11,790 patients. Majority of studies used a colchicine dosing regimen of 0.5 mg once daily, with the median follow-up duration ranging from 6 to 36 months. Meta-analytic estimates for stroke incidence highlighted a statistically significant benefit for patients that were administered colchicine compared to placebo (OR 0.47, 95% CI 0.27-0.81, p = 0.006), and a non-significant benefit for myocardial infarction. There was no significant association between colchicine treatment and the adverse effects of gastrointestinal symptoms and myopathy/myalgia.

CONCLUSIONS

The use of colchicine reduces the risk of stroke in patients with a history of coronary artery disease, without a significant increase in gastrointestinal and myopathy/myalgia adverse effects.

Application of multivariate linear regression models for selection of deep eutectic solvent for extraction of apigenin and luteolin from Chrysanthemum indicum L

INTRODUCTION

Among a variety of compounds presented in chrysanthemum, apigenin and luteolin are the two main components that play a major role in numerous biological activities of this herb.

OBJECTIVES

We aimed to obtain linear models showing the dependence of the yield of extraction of apigenin and luteolin on the composition of deep eutectic solvent and investigate the extraction of these two ingredients from Chrysanthemum indicum L.

METHODS

Two models showing the dependence of luteolin and apigenin concentrations on the composition of the solvent were established using a multilinear regression algorithm and were applied to screen 119 different solvents. After that, the extraction process was optimized using response surface methodology and an artificial neural network. Apigenin and luteolin were recovered from the extract by the combination of distillation and addition of water.

RESULTS

The screening results on 119 solvents revealed that choline chloride-acetic acid (1:4) was the most suitable deep eutectic solvent. It was showed that both response surface methodology and the artificial neural network could accurately determine the optimal conditions of extraction of apigenin and luteolin from C. indicum L., including time of extraction (65 minutes), temperature of extraction (90°C) and water content (20%). By the combination of distillation and addition of water, apigenin and luteolin could be effectively recovered from the deep eutectic solvent extract with a recovery rate of over 80%.

CONCLUSIONS

Deep eutectic solvent could be used as an effective green alternative to the conventional solvents for the extraction of bioactive compounds from plants.

Acute Oral Toxicity Assessment and Anti-hyperuricemic Activity of Alocasia longiloba Extracts on Sprague-Dawley Rats

Hyperuricemia is defined as a metabolic abnormality that occurs when serum uric acid (UA) level is abnormally high in the body. We previously reported that A. longiloba possesses various important phytochemicals and in vitro xanthine oxidase activity. Despite A. longiloba ethnomedicinal benefits, its toxicity and anti-hyperuricemic effects have not been reported. The present study was carried out to ensure the safety and investigate the anti-hyperuricemic effects of A. longiloba fruit and petiole ethanolic extracts on rats. In the acute toxicity study, extracts were orally administered at a dose of 2000 mg/kg bodyweight and closely monitored for 2-week for any toxicity effects. The rats were then sacrificed and samples were collected and analyzed for hematological, biochemical, and histopathological parameters. The anti-hyperuricemic effect of A. longiloba fruit or petiole extract was investigated through determination of UA levels on potassium oxonate (PO)-induced hyperuricemic rats. Extracts or standard drug treatments were orally administrated 1-h after PO administration for 14-day. Animals were euthanized and samples were collected for further experiments. The toxicity results show, no significant changes were observed in behavioral, bodyweight changes in experimental groups compared to the control. Moreover, there were no significant changes in hematological, biochemical, and histological parameters between extracts treated and control group. In the anti-hyperuricemia study, the fruit and petiole extracts treatments significantly reduced the level of UA in serum compared to the hyperuricemic model group. This study demonstrated that the extracts of A. longiloba have anti-hyperuricemic activity and was found to be non-toxic to rats in acute toxicity test.

Enhancement of Anti-Inflammatory Activity of Optimized Niosomal Colchicine Loaded into Jojoba Oil-Based Emulgel Using Response Surface Methodology

Recent progression in investigational studies aiming to integrate natural products and plant oils in developing new dosage forms that would provide optimal therapeutic effect. Therefore, the aim of the present exploration was to inspect the influence of jojoba oil in boosting the anti-inflammatory effect of colchicine natural product. To our knowledge, there is no formulation comprising colchicine and jojoba oil together to form a niosomal emulgel preparation anticipated for topical application. Colchicine is a natural product extracted from Colchicum autumnale that has been evidenced to show respectable anti-inflammatory activity. Owing to its drawbacks and low therapeutic index, it was preferable to be formulated into topical dosage form. The current study inspected colchicine transdermal delivery by developing niosomal preparation as a potential nanocarrier included into emulgel prepared with jojoba oil. Box Behnken design was constructed to develop 17 niosomal emulgel formulations. The optimized colchicine niosomal emulgel was evaluated for its physical characteristics and in vitro release studies. The in vivo anti-inflammatory activity was estimated via carrageenan-induced rat hind paw edema method. The developed colchicine niosomal preparation revealed particle size of 220.7 nm with PDI value 0.22, entrapment efficiency 65.3%. The formulation was found to be stable showing no significant difference in particle size and entrapment efficiency up on storage at 4 °C and 25 °C for 3 months. The optimized colchicine niosomal emulgel exhibited a pH value 6.73, viscosity 4598 cP, and spreadability 38.3 mm. In vitro release study of colchicine from niosomal emulgel formulation was around 52.4% over 6 h. Apparently, the proficient anti-inflammatory activity of colchicine niosomal emulgel was confirmed via carrageenan-induced rat hind paw edema test. Overall, the results recommend the combination of niosomal preparation with jojoba oil-based emulgel that might signify a favorable delivery of anti-inflammatory drug such as colchicine.

Colchicine: Isolation, LC-MS QTof Screening, and Anticancer Activity Study of Gloriosa superba Seeds

Colchicine was extracted from Gloriosa superba seeds using the Super Critical Fluid (CO2) Extraction (SCFE) technology. The seeds were purified upto 99.82% using column chromatography. Colchicine affinity was further investigated for anticancer activity in six human cancer cell lines, i.e., A549, MCF-7, MDA-MB231, PANC-1, HCT116, and SiHa. Purified colchicine showed the least cell cytotoxicity and antiproliferation and caused no G2/M arrest at clinically acceptable concentrations. Mitotic arrest was observed in only A549 and MDA-MB231 cell lines at 60nM concentration. Our finding indicated the possible use of colchicine at a clinically acceptable dose and provided insight into the science behind microtubule destabilization. However, more studies need to be conducted beforethese findings could be established.

Countrywide prevalence of critical drug interactions in Hungarian outpatients: a retrospective analysis of pharmacy dispensing data

Background

Drug-drug interactions (DDIs) present a significant source of adverse drug reactions. Despite being one of the commonly cited risks to patient safety, prevention of DDIs still poses a challenge to healthcare systems. The prevalence of DDIs can be used as a quality indicator for the safety of prescribing. With the analysis of drug utilization databases, real-world data on critical DDIs can be obtained. The aim of this study was to establish a list of critical DDIs and estimate their prevalence in the Hungarian outpatient population.

Methods

Since there is no conclusive and generally accepted repository of high-risk DDIs, a systematic search of the literature for consensus-based lists was performed. Based on these results and their analysis with 5 interaction compendia, we propose a simple methodology to identify critical combinations. Present study focused on DDIs which are (1) of high clinical importance thus being most likely to cause significant harm if not detected, (2) well-supported by available evidence and (3) affect drugs which are routinely dispensed in the community pharmacy setting. A retrospective analysis of prescriptions filled between 2013 and 2016 was performed. The source of drug utilization data was the IQVIA’s national prescription fill database. The number of interacting drug pairs dispensed at the same time to the same patient was established.

Results

After excluding drugs with low dispensing rates, the analysis covered 39 DDIs. The distribution of risk categories of the analysed DDIs was inconsistent among different drug interaction compendia. The total number of prescriptions filled varied between 173924449 and 176368468 per year. The prevalence of the selected potential DDIs ranged from 0.00 to 355.89 per 100000 prescriptions per year. There was significant variation between how the number of cases had changed for each DDI throughout the study period, no general tendency could have been described.

Conclusions

There were 1.8 million cases of co-dispensing each year, where prescribers’ and community pharmacists’ role in recognizing and managing potentially serious interactions was or would have been critical. The method presented to identify high-risk DDIs can serve as a starting point for the much-needed improvement of routine interaction screening.

Electronic supplementary material

The online version of this article (10.1186/s40360-019-0311-0) contains supplementary material, which is available to authorized users.

Clinically relevant mutations in the ABCG2 transporter uncovered by genetic analysis linked to erythrocyte membrane protein expression

The ABCG2 membrane protein is a key xeno- and endobiotic transporter, modulating the absorption and metabolism of pharmacological agents and causing multidrug resistance in cancer. ABCG2 is also involved in uric acid elimination and its impaired function is causative in gout. Analysis of ABCG2 expression in the erythrocyte membranes of healthy volunteers and gout patients showed an enrichment of lower expression levels in the patients. By genetic screening based on protein expression, we found a relatively frequent, novel ABCG2 mutation (ABCG2-M71V), which, according to cellular expression studies, causes reduced protein expression, although with preserved transporter capability. Molecular dynamics simulations indicated a stumbled dynamics of the mutant protein, while ABCG2-M71V expression in vitro could be corrected by therapeutically relevant small molecules. These results suggest that personalized medicine should consider this newly discovered ABCG2 mutation, and genetic analysis linked to protein expression provides a new tool to uncover clinically important mutations in membrane proteins.

Effects on tubulin polymerization and down-regulation of c-Myc, hTERT and VEGF genes by colchicine haloacetyl and haloaroyl derivatives

Several colchicine analogues in which the N-acetyl residue has been replaced by haloacetyl, cyclohexylacetyl, phenylacetyl and various aroyl moieties have been synthesized. The cytotoxic activities of the synthesized compounds have been measured on three tumor cell lines (HT-29, MCF-7 and A549) and on one non-tumor cell line (HEK-293). These compounds exhibit high antiproliferative activities at the nanomolar level, in many cases with a higher potency than colchicine itself. Some of the compounds, particularly the haloacetyl derivatives, inhibit the polymerization of tubulin in a similar manner as colchicine. As regards the cell cycle, the most active compounds are the chlorobenzoyl and bromobenzoyl derivatives, which cause cell cycle arrest at the G2/M phase when tested at 20 nM, and the bromoacetyl derivative, which arrests the cell cycle at 15 nM. In addition, these colchicine derivatives have shown fairly active downregulating the expression of the c-Myc, hTERT and VEGF genes, as well as VEGF protein secretion, at very low concentrations.

Current and future therapies for gout

INTRODUCTION

Gout is a common disease responsible for recurrent flares triggered by the deposition of monosodium urate crystals secondary to longstanding hyperuricaemia. The management of gout implies both the treatment of flares and the treatment of hyperuricaemia itself. Recent improvement in the understanding of the disease led to the development of new drugs. Areas covered: This review covers data related to 'old' treatments of flares and hyperuricaemia, evidence on the recently approved drugs and emerging therapies in development. Expert opinion: Recent data provide a good grasp of the optimal use of colchicine, corticosteroids and NSAIDs for the treatment of flares. Interleukin-1 blocking therapies have an increasing role in the management of difficult-to-treat gout. Sub-optimal use of allopurinol is common and its potency to reduce serum uric acid (SUA) levels is underestimated. Febuxostat effectively reduces SUA levels. New uricosurics, notably lesinurad and arhalofenate, in combination with xanthine oxidase inhibitors, offer promising perspectives to help a greater number of patients achieve sufficient SUA reduction.

Colchicine metallocenyl bioconjugates showing high antiproliferative activities against cancer cell lines

Ferrocenyl and ruthenocenyl conjugates with colchicine have been synthesised and their cytotoxic activity, influence on the cell cycle, and interactions with tubulin were evaluated.

Colchicine prevents NSAID-induced small intestinal injury by inhibiting activation of the NLRP3 inflammasome

The inflammasome is a large, multiprotein complex that consists of a nucleotide-binding oligomerization domain-like receptor (NLR), an apoptosis-associated speck-like protein containing a caspase recruitment domain, and pro-caspase-1. Activation of the inflammasome results in cleavage of pro-caspase-1 into cleaved caspase-1, which promotes the processing of pro-interleukin (IL)-1β into mature IL-1β. We investigated the effects of colchicine on non-steroidal anti-inflammatory drug (NSAID)-induced small intestinal injury and activation of the NLR family pyrin domain-containing 3 (NLRP3) inflammasome. Colchicine treatment inhibited indomethacin-induced small intestinal injury by 86% (1 mg/kg) and 94% (3 mg/kg) as indicated by the lesion index 24 h after indomethacin administration. Colchicine inhibited the protein expression of cleaved caspase-1 and mature IL-1β, without affecting the mRNA expression of NLRP3 and IL-1β. Although treatment with recombinant IL-1β (0.1 μg/kg) did not change the severity of small intestinal damage, the preventive effects of colchicine were abolished by supplementation with the same dose of recombinant IL-1β. Indomethacin-induced small intestinal damage was reduced by 77%, as determined by the lesion index in NLRP3^−/− mice, and colchicine treatment failed to inhibit small intestinal damage in NLRP3^−/− mice. These results demonstrate that colchicine prevents NSAID-induced small intestinal injury by inhibiting activation of the NLRP3 inflammasome.

2016 updated EULAR evidence-based recommendations for the management of gout

Background

New drugs and new evidence concerning the use of established treatments have become available since the publication of the first European League Against Rheumatism (EULAR) recommendations for the management of gout, in 2006. This situation has prompted a systematic review and update of the 2006 recommendations.

Methods

The EULAR task force consisted of 15 rheumatologists, 1 radiologist, 2 general practitioners, 1 research fellow, 2 patients and 3 experts in epidemiology/methodology from 12 European countries. A systematic review of the literature concerning all aspects of gout treatments was performed. Subsequently, recommendations were formulated by use of a Delphi consensus approach.

Results

Three overarching principles and 11 key recommendations were generated. For the treatment of flare, colchicine, non-steroidal anti-inflammatory drugs (NSAIDs), oral or intra-articular steroids or a combination are recommended. In patients with frequent flare and contraindications to colchicine, NSAIDs and corticosteroids, an interleukin-1 blocker should be considered. In addition to education and a non-pharmacological management approach, urate-lowering therapy (ULT) should be considered from the first presentation of the disease, and serum uric acid (SUA) levels should be maintained at<6 mg/dL (360 µmol/L) and <5 mg/dL (300 µmol/L) in those with severe gout. Allopurinol is recommended as first-line ULT and its dosage should be adjusted according to renal function. If the SUA target cannot be achieved with allopurinol, then febuxostat, a uricosuric or combining a xanthine oxidase inhibitor with a uricosuric should be considered. For patients with refractory gout, pegloticase is recommended.

Conclusions

These recommendations aim to inform physicians and patients about the non-pharmacological and pharmacological treatments for gout and to provide the best strategies to achieve the predefined urate target to cure the disease.

Screening Anti-Cancer Drugs against Tubulin using Catch-and-Release Electrospray Ionization Mass Spectrometry

Tubulin, which is the building block of microtubules, plays an important role in cell division. This critical role makes tubulin an attractive target for the development of chemotherapeutic drugs to treat cancer. Currently, there is no general binding assay for tubulin-drug interactions. The present work describes the application of the catch-and-release electrospray ionization mass spectrometry (CaR-ESI-MS) assay to investigate the binding of colchicinoid drugs to αβ-tubulin dimers extracted from porcine brain. Proof-of-concept experiments using positive (ligands with known affinities) and negative (non-binders) controls were performed to establish the reliability of the assay. The assay was then used to screen a library of seven colchicinoid analogues to test their binding to tubulin and to rank their affinities.

New Colchicine-Derived Triazoles and Their Influence on Cytotoxicity and Microtubule Morphology

A series of new colchicinoids with a variable triazole unit at C-7 was synthesized through Cu(I)-catalyzed 1,3-dipolar cycloaddition (click-chemistry) of a colchicine-derived azide with various alkynes and the cytotoxicity against THP-1 and Jurkat cancer cell lines was used for structural optimization. Three particularly active compounds (IC50 ≤ 5 nM) were additionally investigated with respect to their efficacy against relevant solid tumor cell lines (HeLa, A549, and SK MES 1). Besides distorting the microtubule morphology by tubulin depolymerization, one compound also exhibited a pronounced centrosome declustering effect in triple negative breast cancer cells (MDA-MB-231) and nonsmall cell lung cancer cells (H1975).

Interleukin-1 inhibitors for acute gout

BACKGROUND

Acute gout flares cause significant pain and disability and it is important to provide quick and effective pain relief. Traditional options for managing acute flares include colchicine, non-steroidal anti-inflammatory drugs (NSAIDs) and glucocorticoids.

OBJECTIVES

To assess the benefits and harms of interleukin-1 inhibitors (anakinra, canakinumab, rilonacept) in acute gout.

SEARCH METHODS

We searched The Cochrane Library, MEDLINE and EMBASE on 19 June 2013. We applied no date or language restrictions. We performed a handsearch of the abstracts from the European League Against Rheumatism (EULAR) (2009 to 2012) and American College of Rheumatology (ACR) (2009 to 2011) conferences and of the references of all included trials. We also screened the Clinical Trials Registry Platform of the World Health Organization and Clinical Trials Registry Platform of the US National Institutes of Health.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-randomised clinical trials (controlled clinical trials (CCTs)) assessing an interleukin-1 inhibitor (anakinra, canakinumab or rilonacept) against placebo or another active treatment (colchicine, paracetamol, NSAIDs, glucocorticoids (systemic or intra-articular), adrenocorticotropin hormone, a different interleukin-1 blocking agent or a combination of any of the above) in adults with acute gout.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, assessed the risk of bias and extracted the data. If appropriate, we pooled data in a meta-analysis. We assessed the quality of the evidence using the GRADE approach.

MAIN RESULTS

We included four studies (806 participants) in the review. The studies had an unclear risk of selection bias and low risk of performance and attrition biases. One study each had an unclear risk of detection and selection bias.Three studies (654 participants) compared subcutaneous canakinumab compared with intramuscular triamcinolone acetonide 40 mg in the treatment of acute gout flares of no more than five days' duration. Doses of canakinumab were varied (10 to 150 mg), but most people (255/368) were treated with canakinumab 150 mg. None of the studies provided data on participant-reported pain relief of 30% or greater. Moderate-quality evidence indicated that canakinumab 150 mg was probably superior to triamcinolone acetonide 40 mg in terms of pain relief, resolution of joint swelling and in achieving a good treatment response at 72 hours following treatment, but was probably associated with an increased risk of adverse events.Mean pain (0- to 100-mm visual analogue scale (VAS), where 0 mm was no pain) was 36 mm after triamcinolone acetonide treatment; pain was further reduced by a mean of 11 mm with canakinumab treatment (mean difference (MD) -10.6 mm, 95% confidence interval (CI) -15.2 to -5.9). Forty-four per cent of participants treated with canakinumab had resolution of joint swelling at 72 hours compared with 32% of participants treated with triamcinolone (risk ratio (RR) 1.39, 95% CI 1.11 to 1.74, number needed to treat for an addition beneficial outcome (NNTB) 9); 65% of participants treated with canakinumab assessed their response to treatment as good or excellent compare with 47% of participants treated with triamcinolone acetonide (RR 1.37, 95% CI 1.16 to 1.61, NNTB 6). Function or health-related quality of life were not measured. In both groups, 0.7% of participants withdrew from treatment (RR 1.1, 95% CI 0.2 to 7.2); there was one death and one alteration of laboratory results in each of the treatment groups. Adverse events were more frequent in participants receiving canakinumab (61%) compared with triamcinolone acetonide (51%; RR 1.2, 95% CI 1.1 to 1.4, number needed to treat for an addition harmful outcome (NNTH) 10).Low-quality evidence from one study (152 participants with an acute gout flare of no more than 48 hours' duration and affecting fewer than four joints) comparing rilonacept 320 mg with indomethacin (50 mg three times a day for three days followed by 25 mg three times a day for up to nine days) indicated that indomethacin may improve pain more than rilonacept at 24 to 72 hours, and there may be no evidence of a difference in withdrawal rates or adverse events. The mean change (improvement) in pain from baseline with indomethacin was 4.3 points (measured on a 0 to 10 numerical rating scale, where 0 was no pain); pain was improved by a mean of only 2.5 points with rilonacept (MD 2.52, 95% CI 0.29 to 4.75, 25% less improvement in absolute pain with rilonacept). Inflammation, function health-related quality of life and participant global assessment of treatment success were not measured. Rates of study withdrawals due to adverse events were low in both groups: 1/75 (1%) participants in the rilonacept group compared with 2/76 (3%) participants in the indomethacin group (RR 0.5, 95% CI 0.05 to 5.5). Adverse events were reported in 27/75 (36%) participants in the rilonacept group and 23/76 (30%) in the indomethacin group (RR 1.2, 95% CI 0.8 to 1.9).

AUTHORS' CONCLUSIONS

Moderate-quality evidence indicated that compared with a single suboptimal 40-mg dose of intramuscular injection of triamcinolone acetonide, a single subcutaneous dose of 150 mg of canakinumab probably results in better pain relief, joint swelling and participant-assessed global assessment of treatment response in people with an acute gout flare but is probably associated with an increased risk of adverse events. The cost of canakinumab is over 5000 times higher than triamcinolone acetonide; however, there are no data on the cost-effectiveness of this approach. We found no studies comparing canakinumab with more commonly used first-line therapies for acute gout flares such as NSAIDs or colchicine. Low-quality evidence indicated that compared with maximum doses of indomethacin (50 mg three times a day), 320 mg of rilonacept may provide less pain relief with a similar rate of adverse events.

Fatal colchicine poisoning by accidental ingestion of Colchicum persicum: a case report

Colchicine poisoning can occur not only by taking dosage form but also by ingesting a plant containing colchicine. A 39-year-old man presented to the emergency room with nausea, vomiting, and diarrhea 9 hours after ingestion of wild garlic. Symptoms attributed to food poisoning, and he received supportive cares and discharged. However, he was admitted to the hospital because of severe gastrointestinal presentations 4 hours later. He received treatments based on the diagnosis of acute gastroenteritis. The patient was in a fair condition during 30 hours of hospitalization until he suddenly developed respiratory distress and unfortunately died with cardiopulmonary arrest. The deceased body referred to our legal medicine center for determining cause of death and investigating possible medical staff malpractices. Postmortem examination, autopsy, macropathology and micropathology study, and postmortem toxicological analysis were performed. All results were submitted to the medical committee office for decision. The unknown cause of death was disclosed after determination of colchicine in the plant and botanical identification as Colchicum persicum. The committee determined the most probable cause of death as acute cardiopulmonary complications induced by colchicine poisoning and the manner of death as accidental. The medical staff was acquitted of the malpractice.

Pharmacokinetics considerations for gout treatments

INTRODUCTION

Patients with gout often have comorbid conditions such as renal failure, cardiovascular disease and metabolic syndrome. The presence and required treatment of these conditions can make the treatment of gout challenging. Knowledge of the pharmacokinetics of the available drugs for the management of gout is mandatory.

AREAS COVERED

A MEDLINE PubMed search for articles published in English from January 1990 to January 2014 was completed using the terms: pharmacokinetics, colchicine, canakinumab, allopurinol, febuxostat, pegloticase, gout, toxicity, drug interaction.

EXPERT OPINION

Colchicine is a drug with a narrow therapeutic-toxicity window. Co-prescription with strong CYP3A4 or P-glycoprotein inhibitors can greatly modify its pharmacokinetics and is to be avoided. Elimination of canakinumab mainly occurs via intracellular catabolism, following receptor mediator endocytosis. Canakinumab appears to be a good alternative for patients with contraindications to colchicine, NSAIDs and corticosteroids. For patients with renal impairment, some authors recommend that the allopurinol maximum dosage should be adjusted to creatinine clearance. If the urate target cannot be achieved, the therapy should be switched to febuxostat, which is appropriate with mild-to-moderate renal failure. Anti-pegloticase antibodies affect the pharmacokinetics of the drug because they increase its clearance, with loss of pegloticase activity.

Impact of allopurinol on risk of myocardial infarction

BACKGROUND

Gout therapy includes xanthine oxidase inhibitors (XOI) and colchicine, which have both been associated with decreased cardiovascular risk. However, their effects on major cardiac events, such as myocardial infarction (MI), need to be investigated further.

OBJECTIVES

To investigate whether XOIs and colchicine are associated with decreased risk of MI.

METHODS

This case-control study compared patients with first-ever MI and matched controls. Cases were recruited from the Pharmacoepidemiological General Research on MI registry. Controls were selected from a referent population (n=8444) from general practice settings.

RESULTS

The study sample consisted of 2277 MI patients and 4849 matched controls. Use of allopurinol was reported by 3.1% of cases and 3.8 of controls, and 1.1% of cases and controls used colchicine. The adjusted OR (95% CI) for MI with allopurinol use was 0.80 (0.59 to 1.09). When using less stringent matching criteria that allowed for inclusion of 2593 cases and 5185 controls, the adjusted OR was 0.73 (0.54 to 0.99). Similar results were found on analysis by sex and hypertension status. Colchicine used was not associated with a decreased risk of MI (aOR=1.17 (0.70 to 1.93)).

CONCLUSIONS

Allopurinol may be associated with a reduced risk of MI. No decreased risk of MI was found in colchicine users. Besides its urate-lowering property, allopurinol might have a cardioprotective effect.

Mechanistic aspects of inflammation and clinical management of inflammation in acute gouty arthritis

It has been recently demonstrated that interleukin 1β (IL-1β) plays a central role in monosodium urate crystal-induced inflammation and that the NALP3 inflammasome plays a major role in IL-1β production. These discoveries have offered new insights into the pathogenesis of acute gouty arthritis. In this review, we discuss the molecular mechanisms by which monosodium urate crystals induce acute inflammation and examine the mechanisms of action (MOAs) of traditional anti-inflammatory drugs (e.g., nonsteroidal anti-inflammatory drugs, colchicine, and glucocorticoids) and biologic agents (e.g., the IL-1β antagonists anakinra, rilonacept, and canakinumab) to understand how their MOAs contribute to their safety profiles. Traditional anti-inflammatory agents may act on the IL-1β pathway at some level; however, their MOAs are broad-ranging, unspecific, and biologically complex. This lack of specificity may explain the range of systemic adverse effects associated with them. The therapeutic margins of nonsteroidal anti-inflammatory drugs, colchicine, and glucocorticoids are particularly low in elderly patients and in patients with cardiovascular, metabolic, or renal comorbidities that are frequently associated with gouty arthritis. In contrast, the IL-1β antagonists act on very specific targets of inflammation, which may decrease the potential for systemic adverse effects, although infrequent but serious adverse events (including infection and administration reactions) have been reported. Because these IL-1β antagonists target an early event immediately downstream from NALP3 inflammasome activation, they may provide effective alternatives to traditional agents with minimal systemic adverse effects. Results of ongoing trials of IL-1β antagonists will likely provide clarification of their potential role in the management of acute gouty arthritis.

The antinociceptive and anti-inflammatory effects of the crude extract of Jatropha isabellei in a rat gout model

ETHNOPHARMACOLOGICAL RELEVANCE

Jatropha isabellei Müll Arg. (Euphorbiaceae) is a medicinal plant that has been used in South American folk medicine for the treatment of arthritic diseases, particularly gout.

AIM OF THE STUDY

This study was designed to verify the antinociceptive, anti-inflammatory and hypouricemic potential of Jatropha isabellei.

MATERIALS AND METHODS

Rats were orally administered with the crude extract (100-300 mg/kg) or a fraction that is rich in alkaloids (0.15 mg/kg) of Jatropha isabellei. An intra-articular (i.a.) injection of 50 μl of monosodium urate (MSU) crystals (1.25mg/site) was used to generate the gout model to assess the effect of the treatment on nociception (thermal and mechanical hyperalgesia) and inflammation (oedema and neutrophil infiltration). The effect of Jatropha isabellei on the serum levels of uric acid was evaluated in a model of hyperuricaemia induced by the intraperitoneal injection of potassium oxonate (250 mg/kg). The side effects were analysed using an open-field test, gastric lesion assessment and by measuring the levels of the ALT and AST enzymes.

RESULTS

Our study demonstrated that the crude extract of Jatropha isabellei and a fraction rich in alkaloids were able to prevent the thermal hyperalgesia, mechanical allodynia, oedema and neutrophil infiltration induced by intra-articular MSU injection in rats. On the other hand, treatment with Jatropha isabellei did not alter the uric acid levels increased by potassium oxonate in the hyperuricaemia model. In addition, Jatropha isabellei did not induce gastric lesions or liver damage and did not alter spontaneous locomotor activity.

CONCLUSION

The crude extract of Jatropha isabellei and its fraction rich in alkaloid presents antinociceptive and anti-inflammatory effects in a rat gout model, similar to that observed after treatment with colchicine, supporting the traditional use of this plant in gouty patients.

Effect of cyclosporine on the pharmacokinetics of colchicine in healthy subjects

OBJECTIVE

Colchicine and cyclosporine are often administered together, particularly in patients who have undergone solid-organ transplantation. However, the potential for drug-drug interactions between these agents resulting in colchicine toxicity is high.

METHODS

This study sought to determine the effect of cyclosporine (100-mg capsule) on the pharmacokinetics of the US Food and Drug Administration-approved formulation of colchicine (0.6-mg tablet) after single oral-dose administration in 24 healthy subjects under fasted conditions in a phase 1, single-sequence, 2-period drug-drug interaction trial.

RESULTS

Coadministration of cyclosporine increased colchicine maximum observed plasma concentration, area under the plasma concentration-time curve to the last measurable time point, and area under the plasma concentration-time curve to time infinity on average by 224%, 216%, and 215% (ie, almost doubled), respectively, and decreased colchicine oral clearance on average by 72% (from 48.24 to 13.42 L/h), indicating substantially higher colchicine exposures when combined with cyclosporine, compared with colchicine alone.

CONCLUSION

The dose of colchicine should be reduced by ≥ 50% when colchicine and cyclosporine are administered concurrently for treatment and prophylaxis of gout flares or treatment of patients with familial Mediterranean fever. Health care professionals should be vigilant for potential adverse events during colchicine/cyclosporine coadministration, notably in patients who have undergone solid-organ transplantation.

TRIAL REGISTRATION

www.ClinicalTrials.gov identifier NCT00983931 (http://clinicaltrials.gov/ct2/show/NCT00983931).

The anti-inflammatory drug colchicine lacks efficacy in hidradenitis suppurativa

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic, inflammatory skin disease. Since current treatments are unsatisfactory for many patients, there is a high need for effective drugs for this debilitating disease. Recent pathogenic insights suggest inflammasome activation and IL-1β production are important in HS. Colchicine is efficacious in the IL-1β- and inflammasome-mediated diseases gout, familial Mediterranean fever and Behçet's disease, and therefore a potentially effective drug in HS.

OBJECTIVE

To investigate the efficacy of colchicine in HS.

METHODS

In an open prospective pilot study, 8 HS patients were treated with the accepted gout maintenance regimen of 0.5 mg colchicine b.i.d. orally up to 4 months. Efficacy was assessed by a physician global assessment.

RESULTS

Colchicine treatment did not result in a clinically relevant improvement of disease severity. Three patients experienced nausea and diarrhea as known side effects.

CONCLUSION

Colchicine in the used dose regimen does not ameliorate HS severity.