Review article: monitoring for drug side-effects in inflammatory bowel disease

Contextual AI models for single-cell protein biology

Understanding protein function and developing molecular therapies require deciphering the cell types in which proteins act as well as the interactions between proteins. However, modeling protein interactions across biological contexts remains challenging for existing algorithms. Here, we introduce Pinnacle, a geometric deep learning approach that generates context-aware protein representations. Leveraging a multi-organ single-cell atlas, Pinnacle learns on contextualized protein interaction networks to produce 394,760 protein representations from 156 cell type contexts across 24 tissues. Pinnacle's embedding space reflects cellular and tissue organization, enabling zero-shot retrieval of the tissue hierarchy. Pretrained protein representations can be adapted for downstream tasks: enhancing 3D structure-based representations for resolving immuno-oncological protein interactions, and investigating drugs' effects across cell types. Pinnacle outperforms state-of-the-art models in nominating therapeutic targets for rheumatoid arthritis and inflammatory bowel diseases, and pinpoints cell type contexts with higher predictive capability than context-free models. Pinnacle's ability to adjust its outputs based on the context in which it operates paves way for diverse large-scale context-specific predictions in biology.

Injectable Bioadhesive Hydrogels Scavenging ROS and Restoring Mucosal Barrier for Enhanced Ulcerative Colitis Therapy

Despite the progress in the therapy of ulcerative colitis (UC), long-lasting UC remission can hardly be achieved in the majority of UC patients. The key pathological characteristics of UC include an impaired mucosal barrier and local inflammatory infiltration. Thus, a two-pronged approach aiming at repairing damaged mucosal barrier and scavenging inflammatory mediators simultaneously might hold great potential for long-term remission of UC. A rectal formulation can directly offer preferential and effective drug delivery to inflamed colon. However, regular intestinal peristalsis and frequent diarrhea in UC might cause transient drug retention. Therefore, a bioadhesive hydrogel with strong interaction with intestinal mucosa might be preferable for rectal administration to prolong drug retention. Here, we designed a bioadhesive hydrogel formed by the cross-linking of sulfhydryl chondroitin sulfate and polydopamine (CS-PDA). The presence of PDA would ensure the mucosa-adhesive behavior, and the addition of CS in the hydrogel network was expected to achieve the restoration of the intestinal epithelial barrier. To scavenge the key player (excessive reactive oxygen species, ROS) in inflamed colon, sodium ferulic (SF), a potent ROS inhibitor, was incorporated into the CS-PDA hydrogel. After rectal administration, the SF-loaded CS-PDA hydrogel could adhere to the colonic mucosa to allow prolonged drug retention. Subsequently, sustained SF release could be achieved to persistently scavenge ROS in inflammatory areas. Meanwhile, the presence of CS would promote the restoration of the mucosal barrier. Ultimately, scavenging ROS and restoring the mucosal barrier could be simultaneously achieved via this SF-loaded bioadhesive hydrogel scaffold. Our two-pronged approach might provide new insight for effective UC treatment.

Aloe-derived nanovesicles attenuate inflammation and enhance tight junction proteins for acute colitis treatment

Inflammatory bowel disease (IBD) is a chronic recurrent inflammatory disease of the digestive tract that causes pain and weight loss and also increases the risk of colon cancer. Inspired by the benefits of plant-derived nanovesicles and aloe, we herein report aloe-derived nanovesicles, including aloe vera-derived nanovesicles (VNVs), aloe arborescens-derived nanovesicles (ANVs), and aloe saponaria-derived nanovesicles (SNVs) and evaluate their therapeutic potential and molecular mechanisms in a dextran sulfate sodium (DSS)-induced acute experimental colitis mouse model. Aloe-derived nanovesicles not only facilitate markedly reduced DSS-induced acute colonic inflammation, but also enable the restoration of tight junction (TJ) and adherent junction (AJ) proteins to prevent gut permeability in DSS-induced acute colonic injury. These therapeutic effects are ascribed to the anti-inflammatory and anti-oxidant effects of aloe-derived nanovesicles. Therefore, aloe-derived nanovesicles are a safe treatment option for IBD.

Molecular Mechanisms of the Antitumor Effects of Mesalazine and Its Preventive Potential in Colorectal Cancer

Chemoprevention is one of the ways to fight colorectal cancer, which is a huge challenge in oncology. Numerous pieces of evidence indicate that chronic inflammation in the course of Crohn's disease or ulcerative colitis (UC) is a significant cancer risk factor. Epidemiologic studies suggest that long-term use of non-steroidal anti-inflammatory drugs (NSAIDs), including mesalazine, has beneficial effects on colitis-associated colorectal cancer. Mesalazine is a first-line therapy for UC and is also widely used for maintaining remission in UC. Data showed that mesalazine has antiproliferative properties associated with cyclooxygenase (COX) inhibition but can also act through COX-independent pathways. This review summarizes knowledge about mesalazine's molecular mechanisms of action and chemopreventive effect by which it could interfere with colorectal cancer cell proliferation and survival.

Surface-anchored microbial enzyme-responsive solid lipid nanoparticles enabling colonic budesonide release for ulcerative colitis treatment

Colon-targeted oral drug delivery systems (CDDSs) are desirable for the treatment of ulcerative colitis (UC), which is a disease with high relapse and remission rates associated with immune system inflammation and dysregulation localized within the lining of the large bowel. However, the success of current available approaches used for colon-targeted therapy is limited. Budesonide (BUD) is a corticosteroid drug, and its rectal and oral formulations are used to treat UC, but the inconvenience of rectal administration and the systemic toxicity of oral administration restrict its long-term use. In this study, we designed and prepared colon-targeted solid lipid nanoparticles (SLNs) encapsulating BUD to treat UC by oral administration. A negatively charged surfactant (NaCS-C12) was synthesized to anchor cellulase-responsive layers consisting of polyelectrolyte complexes (PECs) formed by negatively charged NaCS and cationic chitosan onto the SLNs. The release rate and colon-specific release behavior of BUD could be easily modified by regulating the number of coated layers. We found that the two-layer BUD-loaded SLNs (SLN-BUD-2L) with a nanoscale particle size and negative zeta potential showed the designed colon-specific drug release profile in response to localized high cellulase activity. In addition, SLN-BUD-2L exhibited excellent anti-inflammatory activity in a dextran sulfate sodium (DSS)-induced colitis mouse model, suggesting its potential anti-UC applications.

Oral Nanomedicines for siRNA Delivery to Treat Inflammatory Bowel Disease

RNA interference (RNAi) therapies have significant potential for the treatment of inflammatory bowel diseases (IBD). Although administering small interfering RNA (siRNA) via an oral route is desirable, various hurdles including physicochemical, mucus, and cellular uptake barriers of the gastrointestinal tract (GIT) impede both the delivery of siRNA to the target site and the action of siRNA drugs at the target site. In this review, we first discuss various physicochemical and biological barriers in the GI tract. Furthermore, we present recent strategies and the progress of oral siRNA delivery strategies to treat IBD. Finally, we consider the challenges faced in the use of these strategies and future directions of oral siRNA delivery strategies.

Kidney function monitoring to prevent 5-aminosalicylic acid nephrotoxicity: What the gastroenterologist should know

BACKGROUND

The kidney function monitoring is recommended in routine practice to detect 5-aminosalicylic acid (5-ASA) related nephrotoxicity, although is not standardized. The optimal monitoring is unknown, especially the best timing and which tests to perform. We summarized why, how, and when to perform the monitoring for patients treated with 5-ASA and provided an overview of the current guidelines on this topic.

METHOD

Relevant studies on this topic were searched in PubMed, Embase, and Web of Science databases from July to August 2020.

RESULTS

Serum creatinine, the estimated glomerular filtration rate, and 24-h proteinuria are the 3 main tests used for the monitoring in daily practice. Regarding the timing, several monitoring strategies have been proposed and guidelines are available too, but they provide conflicting information. To date, there is no medical evidence-based that one strategy is better than another. Comorbidities, chronic renal disease, use of nephrotoxic drugs or concomitant steroid therapy also impact the nephrotoxicity risk. Based on the literature review we proposed a kidney function monitoring strategy to guide physicians in clinical practice.

CONCLUSION

A baseline assessment should be performed in all patients treated with 5-ASA. The monitoring should be carried out according to the other nephrotoxic factors. A tight monitoring may reduce morbidity and mortality of drug nephrotoxicity.

A newly identified polyunsaturated macamide alleviates dextran sulfate sodium-induced colitis in mice

Macamides are a class of bioactive amide alkaloids found only in maca (Lepidium meyenii). Recent studies have shown that macamide-rich extracts possess various biological activities, such as antioxidative, immune-enhancing, and reproductive health-improving activities. In the present study, N-benzyl docosahexaenamide (NB-DHA), a newly identified macamide with the highest degree of unsaturation among all identified macamides, was identified from the maca extract. Microalgae oil, a docosahexaenoic acid-rich substance, was used as the starting material for the synthesis of NB-DHA. The effects of NB-DHA in colitis-induced mice were evaluated. NB-DHA significantly alleviated weight loss, shortening of colon length, and occult blood occurrence in mice with dextran sulfate sodium-induced colitis. Histological analysis revealed that following the administration of NB-DHA in mice with colitis, the infiltration of inflammatory cells and levels of proinflammatory factors, such as tumor necrosis factor-α, interleukin (IL)-1β, IL-6, and myeloperoxidase, decreased, whereas the level of the anti-inflammatory factor IL-10 increased. Furthermore, the decreased expression of intestinal tight junction proteins caused by colitis was upregulated by the administration of NB-DHA. These results indicate that NB-DHA could be developed as a therapeutic agent for ulcerative colitis.

Significance of Ligand-Anchored Polymers for Drug Targeting in the Treatment of Colonic Disorders

Treatment of a variety of bowel diseases like Crohn's disease, ulcerative colitis, colonic cancers, colonic pathologies, and systemic delivery of drugs at the target sites can be done with the help of targeted drug delivery technique. Conventional colon specific drug delivery systems lack specificity and release significant amount of drug prior reaching the target site. Hence, efficient drug delivery system that ensures effective release of the drug at the colon is still a sought after research arena. Ligand anchored therapy is a strong and effective approach to execute drug delivery in selective target cells, for both, diagnostic, as well as therapeutic reasons. Compared to the regular drugs, such ligand anchored therapy provides added benefit of minimum toxicity and few side effects. Discovery of overexpressed receptors on diseased cells, as compared to healthy cells led to the emergence of active drug targeting. Further, drug resistance constitutes one of the major reasons of the failure of chemotherapy and presents a major obstacle for the effective treatment. The reason behind drug resistance is exposure of pathological cells/pathogens to sub-therapeutic levels of drugs due lack of specificity of therapeutics. Active targeting, specifically taken up by the target cells, can warrant exposure of pathological cells/pathogens to high drug load at the target and sparing non-target cells hence minimal damage to normal cells and least chance of drug resistance. Many ligands like antibodies, aptamers, peptides, folate, and transferrin have been discovered in the past few years. The design of nanocarriers can be incorporated with many different functions which enables functions like imaging and triggered intracellular drug release. The present review article focuses on advances in ligand anchored therapy and its significance on the progress of targeted nanocarriers. It will also establish novel concepts like multi-targeting and multi-functional nanocarriers for the treatment of colonic disorders.

Protocol for a double-blind, randomised, placebo-controlled pilot study for assessing the feasibility and efficacy of faecal microbiota transplant in a paediatric Crohn's disease population: PediCRaFT Trial

INTRODUCTION

Crohn's disease (CD) is a chronic inflammatory condition with transmural involvement of the gastrointestinal tract. Extraintestinal manifestations are common, and the disease burden on patients and the healthcare system is significant. While treatment options have expanded in recent years, they have mainly focused on dampening the immune response, thus carrying notable risks associated with long-term immunosuppression. Faecal microbiota transplant (FMT) targets inflammatory bowel disease (IBD) by modifying intestinal dysbiosis. Limited adult and paediatric data have demonstrated a favourable response to FMT in IBD; however, no randomised controlled trial has yet been published in paediatrics. This double-blind, randomised, placebo-controlled pilot study will assess feasibility and efficacy outcomes of FMT in a paediatric CD population.

METHODS AND ANALYSIS

Forty-five patients between the ages of 3 and 17 years, with established CD or IBD unclassified, will be enrolled 2:1 to undergo FMT intervention or placebo control. Participants will undergo a colonoscopic infusion to the terminal ileum at baseline, followed by oral capsules two times per week for 6 weeks. Outcomes will be measured throughout the intervention period and 18 weeks of subsequent follow-up. Primary outcomes will assess feasibility, including patient recruitment, sample collection and rates of adverse events. Secondary outcomes will address clinical efficacy, including change in clinical response, change in urine metabolome and change in microbiome.

ETHICS AND DISSEMINATION

Ethics approval from the local hospital research ethics board was obtained at the primary site (McMaster Children's Hospital, Hamilton), with ethics pending at the secondary site (Centre Hospitalier Universitaire-Sainte-Justine, Montréal). RBX7455 and RBX2660 are human donor-sourced, microbiota-based therapeutic formulations. Both RBX7455 and RBX2660 are currently undergoing clinical trials to support potential US Food and Drug Administration approval. Approval to conduct this paediatric clinical trial was obtained from Health Canada's Biologics and Genetic Therapies Directorate. The results of this trial will be published in peer-reviewed journals and will help inform a large, multicentre trial in the future.

TRIAL REGISTRATION NUMBER

NCT03378167; pre-results.

Nanoparticles for the regulation of intestinal inflammation: opportunities and challenges

Prevalence of chronic inflammation of the gastrointestinal tract is increasing, emerging as a public health challenge. Conventional drug delivery systems targeting the colon have improved the treatment of inflammatory bowel disease. However, therapy frequently results in inconsistent efficacy and toxicity problems. Novel approaches based on nanoparticles offer several advantages over conventional dosage forms due to their ability to selectively target inflamed tissues. Several formulation efforts have been made in order to obtain increasingly selective nanosized systems, some with promising results in animal models of colitis. Despite all advances, no nanomedicines are yet approved for clinical use in inflammatory bowel disease. This review discusses the most recent efforts made toward the development of nanoparticles for regulating chronic intestinal inflammation.

Oral delivery of siRNA lipid nanoparticles: Fate in the GI tract

Oral delivery, a patient-friendly means of drug delivery, is preferred for local administration of intestinal therapeutics. Lipidoid nanoparticles, which have been previously shown to deliver siRNA to intestinal epithelial cells, have potential to treat intestinal disease. It is unknown, however, whether the oral delivery of these particles is possible. To better understand the fate of lipid nanoparticles in the gastrointestinal (GI) tract, we studied delivery under deconstructed stomach and intestinal conditions in vitro. Lipid nanoparticles remained potent and stable following exposure to solutions with pH values as low as 1.2. Efficacy decreased following exposure to “fed”, but not “fasting” concentrations of pepsin and bile salts. The presence of mucin on Caco-2 cells also reduced potency, although this effect was mitigated slightly by increasing the percentage of PEG in the lipid nanoparticle. Mouse biodistribution studies indicated that siRNA-loaded nanoparticles were retained in the GI tract for at least 8 hours. Although gene silencing was not initially observed following oral LNP delivery, confocal microscopy confirmed that nanoparticles entered the epithelial cells of the mouse small intestine and colon. Together, these data suggest that orally-delivered LNPs should be protected in the stomach and upper intestine to promote siRNA delivery to intestinal epithelial cells.

Crohn Disease: Epidemiology, Diagnosis, and Management

Crohn disease is a chronic idiopathic inflammatory bowel disease condition characterized by skip lesions and transmural inflammation that can affect the entire gastrointestinal tract from the mouth to the anus. For this review article, we performed a review of articles in PubMed through February 1, 2017, by using the following Medical Subject Heading terms: crohns disease, crohn's disease, crohn disease, inflammatory bowel disease, and inflammatory bowel diseases. Presenting symptoms are often variable and may include diarrhea, abdominal pain, weight loss, nausea, vomiting, and in certain cases fevers or chills. There are 3 main disease phenotypes: inflammatory, structuring, and penetrating. In addition to the underlying disease phenotype, up to a third of patients will develop perianal involvement of their disease. In addition, in some cases, extraintestinal manifestations may develop. The diagnosis is typically made with endoscopic and/or radiologic findings. Disease management is usually with pharmacologic therapy, which is determined on the basis of disease severity and underlying disease phenotype. Although the goal of management is to control the inflammation and induce a clinical remission with pharmacologic therapy, most patients will eventually require surgery for their disease. Unfortunately, surgery is not curative and patients still require ongoing therapy even after surgery for disease recurrence. Importantly, given the risks of complications from both Crohn disease and the medications used to treat the disease process, primary care physicians play an important role in optimizing the preventative care management to reduce the risk of complications.

Safety of treatments for inflammatory bowel disease: Clinical practice guidelines of the Italian Group for the Study of Inflammatory Bowel Disease (IG-IBD)

Inflammatory bowel diseases are chronic conditions of unknown etiology, showing a growing incidence and prevalence in several countries, including Italy. Although the etiology of Crohn's disease and ulcerative colitis is unknown, due to the current knowledge regarding their pathogenesis, effective treatment strategies have been developed. Several guidelines are available regarding the efficacy and safety of available drug treatments for inflammatory bowel diseases. Nevertheless, national guidelines provide additional information adapted to local feasibility, costs and legal issues related to the use of the same drugs. These observations prompted the Italian Group for the Study of Inflammatory Bowel Disease (IG-IBD) to establish Italian guidelines on the safety of currently available treatments for Crohn's disease and ulcerative colitis. These guidelines discuss the use of aminosalicylates, systemic and low bioavailability corticosteroids, antibiotics (metronidazole, ciprofloxacin, rifaximin), thiopurines, methotrexate, cyclosporine A, TNFα antagonists, vedolizumab, and combination therapies. These guidelines are based on current knowledge derived from evidence-based medicine coupled with clinical experience of a national working group.

Investigation of mitigating effect of colon-specific prodrugs of boswellic acid on 2,4,6-trinitrobenzene sulfonic acid-induced colitis in Wistar rats: Design, kinetics and biological evaluation

AIM

To develop a colon-targeting bioreversible delivery system for β-boswellic acid (BBA) and explore utility of its prodrugs in 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in rats.

METHODS

Synthesis of 4 co-drugs of BBA with essential amino acids was achieved by CDI coupling, followed by their spectral characterization. In vitro kinetics were studied by HPLC in aqueous buffers, homogenates of gastrointestinal tract and fecal matter. In vivo kinetic studies were performed in Wistar rat plasma, urine and feces. The prodrugs were screened in TNBS-induced colitis modeled Wistar rats. Statistical significance was assumed at P < 0.05, P < 0.01, P < 0.001 when compared with disease controls using one-way and two-way ANOVAs.

RESULTS

Prodrugs were stable in 0.05 mol/L HCl buffer (pH 1.2) and stomach homogenates. Negligible hydrolysis was observed in phosphate buffer and intestinal homogenates. Substantial release (55%-72% and 68%-86%) of BBA was achieved in rat fecal matter and homogenates of colon. In vivo studies of BBA with L-tryptophan (BT) authenticated colon-specific release of BBA. But, surprisingly substantial concentration of BBA was seen to reach the systemic circulation due to probable absorption through colonic mucosa. Site-specifically enhanced bioavailability of BBA could be achieved in colon, which resulted in demonstration of significant mitigating effect on TNBS-induced colitis in rats without inducing any adverse effects on stomach, liver and pancreas. Prodrug of BT was found to be 1.7% (P < 0.001) superior than sulfasalazine in reducing the inflammation to colon among all prodrugs tested.

CONCLUSION

The outcome of this study strongly suggests that these prodrugs might have dual applicability to inflammatory bowel disease and chronotherapy of rheumatoid arthritis.

The Impact of Dietary Interventions on the Symptoms of Inflammatory Bowel Disease: A Systematic Review

Diet may be a successful part of the treatment plan for improving outcome in patients with inflammatory bowel disease (IBD). This study aimed to systematically review all published clinical trials evaluating the effects of a regular diet on symptoms of IBD. Three medical databases were searched for clinical trials evaluating an intervention that involved dietary manipulation using a regular diet on adults with IBD whose symptoms were objectively measured before and after the intervention. The most common types of regular diet interventions that we observed in the literature fell into the following three categories: low residue/low fiber diets, exclusion diets, or other specific diets. Of all included studies, the few that were of higher quality and that observed a statistically significant improvement in symptoms in the diet group compared to the control group fell under the exclusion diet group or the other specific diet group. We were able to identify several high quality clinical trials evaluating dietary manipulations on symptoms of IBD. Exclusion diets and the low FODMAP diet are two areas identified in this review that show promise for having therapeutic benefits for patients with IBD.

Oral pathology in inflammatory bowel disease

The incidence of inflammatory bowel diseases (IBD) - Crohn’s disease (CD) and ulcerative colitis (UC) - has been increasing on a global scale, and progressively, more gastroenterologists will be included in the diagnosis and treatment of IBD. Although IBD primarily affects the intestinal tract, extraintestinal manifestations of the disease are often apparent, including in the oral cavity, especially in CD. Specific oral manifestations in patients with CD are as follows: indurate mucosal tags, cobblestoning and mucogingivitis, deep linear ulcerations and lip swelling with vertical fissures. The most common non-specific manifestations, such as aphthous stomatitis and angular cheilitis, occur in both diseases, while pyostomatitis vegetans is more pronounced in patients with UC. Non-specific lesions in the oral cavity can also be the result of malnutrition and drugs. Malnutrition, followed by anemia and mineral and vitamin deficiency, affects the oral cavity and teeth. Furthermore, all of the drug classes that are applied to the treatment of inflammatory bowel diseases can lead to alterations in the oral cavity due to the direct toxic effects of the drugs on oral tissues, as well as indirect immunosuppressive effects with a risk of developing opportunistic infections or bone marrow suppression. There is a higher occurrence of malignant diseases in patients with IBD, which is related to the disease itself and to the IBD-related therapy with a possible oral pathology. Treatment of oral lesions includes treatment of the alterations in the oral cavity according to the etiology together with treatment of the primary intestinal disease, which requires adequate knowledge and a strong cooperation between gastroenterologists and specialists in oral medicine.

A mechanistic review on plant-derived natural compounds as dietary supplements for prevention of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a recurrent idiopathic inflammatory condition, characterized by disruption of the gut mucosal barrier. This mechanistic review aims to highlight the significance of plant-derived natural compounds as dietary supplements, which can be used in addition to restricted conventional options for the prevention of IBD and induction of remission. Various clinical trials confirmed the effectiveness and tolerability of natural supplements in patients with IBD. Mounting evidence suggests that these natural compounds perform their protective and therapeutic effect on IBD through numerous molecular mechanisms, including anti-inflammatory and immunoregulatory, anti-oxidative stress, modulation of intracellular signaling transduction pathways, as well as improving gut microbiota. In conclusion, natural products can be considered as dietary supplements with therapeutic potential for IBD, provided that their safety and efficacy is confirmed in future well-designed clinical trials with adequate sample size.

Palmitoylethanolamide Modulates Inflammation-Associated Vascular Endothelial Growth Factor (VEGF) Signaling via the Akt/mTOR Pathway in a Selective Peroxisome Proliferator-Activated Receptor Alpha (PPAR-α)-Dependent Manner

BACKGROUND AND AIM

Angiogenesis is emerging as a pivotal process in chronic inflammatory pathologies, promoting immune infiltration and prompting carcinogenesis. Ulcerative Colitis (UC) and Crohn's Disease (CD) represent paradigmatic examples of intestinal chronic inflammatory conditions in which the process of neovascularization correlates with the severity and progression of the diseases. Molecules able to target the angiogenesis have thus the potential to synergistically affect the disease course. Beyond its anti-inflammatory effect, palmitoylethanolamide (PEA) is able to reduce angiogenesis in several chronic inflammatory conditions, but no data about its anti-angiogenic activity in colitis have been produced, yet.

METHODS

The effects of PEA on inflammation-associated angiogenesis in mice with dextran sulphate sodium (DSS)-induced colitis and in patients with UC were assessed. The release of Vascular Endothelial Growth Factor (VEGF), the hemoglobin tissue content, the expression of CD31 and of phosphatidylinositol 3-kinase/Akt/mammalian-target-of-rapamycin (mTOR) signaling axis were all evaluated in the presence of different concentrations of PEA and concomitant administration of PPAR-α and -γ antagonists.

RESULTS

Our results demonstrated that PEA, in a selective peroxisome proliferator activated receptor (PPAR)-α dependent mechanism, inhibits colitis-associated angiogenesis, decreasing VEGF release and new vessels formation. Furthermore, we demonstrated that the mTOR/Akt axis regulates, at least partly, the angiogenic process in IBD and that PEA directly affects this pathway.

CONCLUSIONS

Our results suggest that PEA may improve inflammation-driven angiogenesis in colonic mucosa, thus reducing the mucosal damage and potentially affecting disease progression and the shift towards the carcinogenesis.

Review article: the safety of therapeutic drugs in male inflammatory bowel disease patients wishing to conceive

BACKGROUND

Many therapeutic drugs are used by patients with inflammatory bowel disease, often around the time of conception. The pregnancy outcomes of males and females exposed to these therapeutics needs to be examined and this information is necessary to counsel patients appropriately.

AIM

To review the literature describing male infertility and inflammatory bowel disease to educate practitioners of the impact of inflammatory bowel disease on male reproduction and the impact of therapeutics on pregnancy outcomes.

METHODS

We performed a PubMed search using the search terms 'male infertility,' 'Crohn's disease,' 'inflammatory bowel disease,' 'ulcerative colitis,' 'ciprofloxacin AND infertility,' 'metronidazole AND infertility,' 'sulfasalazine AND infertility,' 'azathioprine AND infertility,' 'methotrexate AND infertility,' 'ciclosporin AND infertility,' 'corticosteroids AND infertility,' 'infliximab AND male fertility,' 'infliximab AND infertility,' 'infliximab AND foetus,' 'infliximab AND paternal exposure' and 'infliximab AND sperm.' References from selected papers were reviewed and used if relevant.

RESULTS

Over half of male patients with IBD have some degree of infertility, compared to 8-17% of the general population. Semen parameters including total count, motility and morphology may be adversely affected by therapeutics. IBD medications in males do not increase foetal risk with the possible exception of azathioprine and mercaptopurine; however, increased foetal risk is seen in other drugs if taken by female patients.

CONCLUSIONS

It is recognised that male infertility is often impacted with therapeutic drugs used to treat inflammatory bowel disease; however, the effects of the paternal drug exposure at the time of conception and exposure in utero should be considered to counsel patients appropriately.

Drug delivery strategies in the therapy of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a frequently occurring disease in young people, which is characterized by a chronic inflammation of the gastrointestinal tract. The therapy of IBD is dominated by the administration of anti-inflammatory and immunosuppressive drugs, which suppress the intestinal inflammatory burden and improve the disease-related symptoms. Established treatment strategies are characterized by a limited therapeutical efficacy and the occurrence of adverse drug reactions. Thus, the development of novel disease-targeted drug delivery strategies is intended for a more effective therapy and demonstrates the potential to address unmet medical needs. This review gives an overview about the established as well as future-oriented drug targeting strategies, including intestine targeting by conventional drug delivery systems (DDS), disease targeted drug delivery by synthetic DDS and disease targeted drug delivery by biological DDS. Furthermore, this review analyses the targeting mechanisms of the respective DDS and discusses the possible field of utilization in IBD.

Dress Syndrome Induced by Sulphasalazine

DRESS syndrome (Drug rash with eosinophilia and systemic symptoms) is a severe drug-induced hypersensitivity syndrome characterized by diffuse skin rash, fever, eosinophilia, atypical lymphocytes and organ involvement. We report a case of drug reaction with eosinophilia and systemic symptoms (DRESS) to sulphasalazine. A 54-year-old woman developed a widespread papulovesicular rash after treatment with sulphasalazine (1000 mg daily). She was successfully treated with systemic corticosteroids.

5-Aminosalicylates and renal function monitoring in inflammatory bowel disease: a nationwide survey

BACKGROUND AND AIM

5-Aminosalicylates (ASA) are widely used in inflammatory bowel disease (IBD). Nephrotoxicity has been described in some IBD patients treated with 5-ASA. Whether physicians managing these patients are monitoring renal function in daily practice is unknown. The aims of this paper were to investigate how private gastroenterologists monitor renal function and manage renal failure in IBD patients treated with oral 5-ASA therapy.

METHODS

This was a web-based cross sectional national survey which was conducted among private gastroenterologists.

RESULTS

A total of 249 practitioners completed the survey. Eighty two percent (n=205) of responders declared that they always monitor renal function. The respondents monitored twice a year Glomerular Filtration Rate (eGFR) using Modification of Diet in Renal Disease (MDRD) [90% (n=225)] and Creatinine Clearance (CCr) using a 24-hour urine collection [51% (n=126)]. Blood electrolytes, 24-hour urinary protein rate and dipsticks are performed by 41%, 39% and 22% of practitioners, respectively. Before oral 5-ASA initiation, 59% (n=148) of respondents screen for renal failure. In case of elevated serum creatinine, a nephrologist's opinion is asked by 80% (n=200) of responders and by 76% (n=189) of respondents before treatment initiation.

CONCLUSIONS

Most gastroenterologists are monitoring renal function once or twice a year in IBD patients on 5-ASA. Less than two thirds of them screen for renal failure before treatment initiation. MDRD is mainly used, but a wide range of parameters is evaluated.

Safety of thiopurine therapy in inflammatory bowel disease: long-term follow-up study of 3931 patients

BACKGROUND

To evaluate the safety of thiopurines in patients with inflammatory bowel disease. To identify predictive factors associated with the development of thiopurine-induced adverse events.

METHODS

Long-term incidence of adverse events was estimated in patients from a prospectively maintained Spanish nationwide database using Kaplan-Meier analysis. Cox regression analysis was performed to identify potential predictive factors of adverse events.

RESULTS

Three thousand nine hundred and thirty-one patients were included. Ninety-five percent of patients were on azathioprine. The median follow-up with thiopurines was 44 months (range, 0-420). Adverse events occurred at a median of 1 month after starting treatment. The cumulative incidence of adverse events was 26%, with an annual risk of 7% per patient-year of treatment. Most frequent adverse events were nausea (8%), hepatotoxicity (4%), myelotoxicity (4%), and pancreatitis (4%). Four patients had lymphoma. Female and Crohn's disease increased the risk of having nausea. The risk of hepatotoxicity was lower in females and higher in Crohn's disease. The risk of myelotoxicity was significantly higher in patients treated with mercaptopurine and in females. The risk of pancreatitis was higher in Crohn's disease. Overall, 17% of patients discontinued thiopurine treatment due to adverse events. Thirty-seven percent of these patients started thiopurines again and 40% of them had adverse events again.

CONCLUSIONS

As many as 1 of 4 patients on thiopurine therapy had adverse events during follow-up. A relatively high proportion of patients (17%) had to discontinue the treatment with thiopurines due to adverse events. However, more than half of patients that restarted thiopurine treatment after its discontinuation due to adverse events tolerated it. Several predictive factors for some adverse events have been identified.

Azathioprine and 6-mercaptopurine for maintenance of remission in ulcerative colitis

BACKGROUND

Maintenance of remission is a major issue in inflammatory bowel disease. In ulcerative colitis, the evidence for the effectiveness of azathioprine and 6-mercaptopurine for the maintenance of remission is still controversial.

OBJECTIVES

To assess the effectiveness and safety of azathioprine and 6-mercaptopurine for maintaining remission of ulcerative colitis.

SEARCH METHODS

The MEDLINE, EMBASE and Cochrane Library databases were searched from inception to June 2012. A manual search was also performed using references from these articles as well as review articles, and proceedings from major gastrointestinal meetings. Authors of maintenance trials were asked about unpublished studies.

SELECTION CRITERIA

Randomized controlled trials of at least 12 months duration that compared azathioprine or 6-mercaptopurine with placebo or standard maintenance therapy (e.g. mesalazine) were included.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data using standard forms. Disagreements were solved by consensus including a third author. Study quality was assessed using the Cochrane risk of bias tool. The primary outcome was failure to maintain clinical or endoscopic remission. Secondary outcomes included adverse events and withdrawal due to adverse events. Analyses were performed separately by type of control (placebo, or active comparator). Pooled risk ratios were calculated based on the fixed-effect model unless heterogeneity was shown. The GRADE approach was used to assess the overall quality of evidence for pooled outcomes.

MAIN RESULTS

Six studies including 286 patients with ulcerative colitis were included in the review. The risk of bias was high in three of the studies due to lack of blinding. Azathioprine was shown to be significantly superior to placebo for maintenance of remission. Fourty-four per cent (51/115) of azathioprine patients failed to maintain remission compared to 65% (76/117) of placebo patients (4 studies, 232 patients; RR 0.68, 95% CI 0.54 to 0.86). A GRADE analysis rated the overall quality of the evidence for this outcome as low due to risk of bias and imprecision (sparse data). Two trials that compared 6-mercaptopurine to mesalazine, or azathioprine to sulfasalazine showed significant heterogeneity and thus were not pooled. Fifty per cent (7/14) of 6-mercaptopurine patients failed to maintain remission compared to 100% (8/8) of mesalamine patients (1 study, 22 patients; RR 0.53, 95% CI 0.31 to 0.90). Fifty-eight per cent (7/12) of azathioprine patients failed to maintain remission compared to 38% (5/13) of sulfasalazine patients (1 study, 25 patients; RR 1.52, 95% CI 0.66 to 3.50). One small study found that 6-mercaptopurine was superior to methotrexate for maintenance of remission. In the study, 50% (7/14) of 6-mercaptopurine patients and 92% (11/12) of methotrexate patients failed to maintain remission (1 study, 26 patients; RR 0.55, 95% CI 0.31 to 0.95). All of the studies which used active comparators were open label. When placebo and active comparator studies were pooled to assess adverse events, there was no statistically significant difference between azathioprine and control in the incidence of adverse events. Nine per cent (11/127) of azathioprine patients experienced at least one adverse event compared to 2% (3/130) of placebo patients (5 studies, 257 patients; RR 2.82, 95% CI 0.99 to 8.01). Patients receiving azathioprine were at significantly increased risk of withdrawing due to adverse events. Eight per cent (8/101) of azathioprine patients withdrew due to adverse events compared to 0% (0/98) of control patients (5 studies, 199 patients; RR 5.43, 95% CI 1.02 to 28.75). Adverse events related to study medication included acute pancreatitis (3 cases) and significant bone marrow suppression (5 cases). Deaths, opportunistic infection or neoplasia were not reported.

AUTHORS' CONCLUSIONS

Azathioprine therapy appears to be more effective than placebo for maintenance of remission in ulcerative colitis. Azathioprine or 6-mercaptopurine may be effective as maintenance therapy for patients who have failed or cannot tolerate mesalazine or sulfasalazine and for patients who require repeated courses of steroids. More research is needed to evaluate superiority over standard maintenance therapy, especially in the light of a potential for adverse events from azathioprine. This review updates the existing review of azathioprine and 6-mercaptopurine for maintenance of remission in ulcerative colitis which was published in the Cochrane Library (Issue 1, 2007).

Comparison of the effect of mesalazine and sulfasalazine on laboratory parameters: a retrospective observational study

PURPOSE

Mesalazine and sulfasalazine are commonly used drugs for the treatment of inflammatory bowel disease. However, there have been few reports with a strict statistical analysis comparing the effects of mesalazine and sulfasalazine on laboratory test results. Therefore, we designed a retrospective cohort study to investigate whether or not differences in clinical laboratory parameters exist between mesalazine and sulfasalazine users.

METHODS

We used data from the Clinical Data Warehouse of Nihon University School of Medicine to identify cohorts of new mesalazine users (n = 303) and sulfasalazine users (n = 67). We used a multivariate regression model and regression adjustment with the propensity score to adjust for differences in baseline covariates between mesalazine and sulfasalazine users, and compared serum levels of creatinine, urea nitrogen, aspartate aminotransferase, alanine aminotransferase, and hematological parameters including red and white blood cell counts and platelet count.

RESULTS

After adjustment, in sulfasalazine users, the mean values for all tests showed no significant change between baseline and during the exposure period. In contrast, in mesalazine users, the mean WBC and platelet counts during the exposure period were significantly lower than those at baseline. Furthermore, mean serum urea nitrogen level during the exposure period was significantly higher than that at baseline. In terms of mean changes in laboratory test values during the exposure period compared with baseline, the reduction of platelet count in mesalazine users was significant in comparison to that in sulfasalazine users.

CONCLUSION

Our findings suggested that the hematological adverse effects of mesalazine treatment might be greater than those of sulfasalazine treatment.

Extracellular glutamate alters mature osteoclast and osteoblast functions

Glutamatergic intercellular communication is involved in many aspects of metabolic homeostasis in normal bone. In bone metastasis, the balance between bone formation and degradation is disrupted. Although the responsible mechanisms are not clear, we have previously identified that cancer cell lines used in bone tumour models secrete glutamate, suggesting that tumour-derived glutamate may disrupt sensitive signalling systems in bone. This study examines the role of glutamate in mature osteoclastic bone resorption, osteoblast differentiation, and bone nodule formation. Glutamate was found to have no effect on the survival or activity of mature osteoclasts, although glutamate transporter inhibition and receptor blockade increased the number of bone resorption pits. Furthermore, transporter inhibition increased the area of resorbed bone while significantly decreasing the number of osteoclasts. Alkaline phosphatase activity and extracellular matrix mineralization were used as measurements of osteoblast differentiation. Glutamate significantly increased osteoblast differentiation and mineralization, but transport inhibitors had no effect. These studies support earlier findings suggesting that glutamate may be more important for osteoclastogenesis than for osteoclast proliferation or functions. Since glutamate is capable of changing the differentiation and activities of both osteoclast and osteoblast cell types in bone, it is reasonable to postulate that tumour-derived glutamate may impact bone homeostasis in bone metastasis.

Inflammatory bowel diseases and the general practitioner's role in a region of Central Italy

BACKGROUND

Inflammatory bowel diseases (IBD) are a serious burden for both patients and health care providers because of the young age at which they occur and their chronic course.

AIM

The purpose of this study was to assess how general practitioners (GPs) in the area of Camerino-Matelica, Marche (Central Italy) manage their patients with IBD.

MATERIALS AND METHODS

Before providing an educational course about IBD to GPs, we administered a simple questionnaire containing 10 multiple-choice questions, allowing for only one possible answer, to GPs in the target area. After the educational course we administered a satisfaction questionnaire and evaluated the hospitalization rates for IBD in the catchment area in the year following the course.

RESULTS

In our GP sample, 71.8% indicated that they needed better instruction regarding IBD to enable them to diagnose the conditions given the difficulties posed by nonspecific symptoms and the need to use invasive diagnostic methods such as colonoscopy. Early results after the educational course for GPs indicate a reduced rate of hospitalization for IBD but these data must be confirmed by future research.

CONCLUSIONS

If specialists and GPs managed IBD patients more carefully, their patients would probably suffer from fewer relapses and would have a better quality of life, which would be likely to mean considerable cost savings for the public health care system and society in general.

Managing the risks of IBD therapy

Successful management of the patient with inflammatory bowel disease (IBD) involves not only the induction and maintenance of remission, but also the optimization of the benefit-to-risk equation to achieve the greatest gain in quality of life. These risks range from intolerance to prescribed medications to potentially life-threatening sequelae (eg, sepsis) of immune suppression. A proper awareness of risk on the part of the physician and education of the patient can lead to early detection and institution of an appropriate management plan, including risk management and, optimally, primary prevention (eg, prophylactic vaccination). One should take the opportunity regularly to reassess the utility and efficacy of existing therapy, with the provision of ineffective therapies mandating urgent review. Overall, optimal management of the patient with IBD requires open dialogue between clinician and patient so that both are cognizant of the goals, benefits, and potential risks of therapy.

Effect of 5-aminosalicylates on renal function in patients with inflammatory bowel disease: 4-year follow-up study

OBJECTIVE

Nephrotoxicity has been described in some patients with inflammatory bowel disease (IBD) treated with 5-aminosalicylates (5-ASA). Our aim was to conduct a retrospective study of IBD patients, both with and without 5-ASA treatment, who underwent regular evaluation of renal function over a 4-year period.

METHODS

Serum creatinine was measured before the start of 5-ASA therapy, and thereafter yearly up to 4 years. Creatinine clearance (Cl(Cr)) was estimated from serum creatinine (Cockroft and Gault formula). The influence of 5-ASA treatment on renal function was assessed by univariate and multivariate analysis.

RESULTS

A total of 150 IBD patients (ulcerative colitis in 45%, Crohn's disease in 55%) were included. Sixty-two patients were receiving 5-ASAs (95% coated mesalazine, mean dose 1.9 +/- 0.8 g/day). Both serum creatinine levels and ClCr were similar in patients with and without 5-ASA treatment, and remained stable throughout the 4-year follow-up in patients taking 5-ASAs. In the multivariate analysis, 5-ASA treatment (or its dose) was not correlated with serum creatinine levels or Cl(Cr). No interstitial nephritis was reported during follow-up.

CONCLUSION

5-ASA-related renal disease was not found in our series, suggesting that the occurrence of renal impairment in IBD patients receiving these drugs is exceptional. Our results do not support the recommendation of serum creatinine monitoring in patients receiving 5-ASA treatment.

[Severe tubulo-interstitial nephritis secondary to 5-ASA]

We report a new case of chronic interstitial nephritis in a patient with ulcerative colitis diagnosed in 2002 who was originally treated with 5-ASA. Three years later deterioration of renal function was apparent with an increase in serum creatinine, which was normal before treatment. Withdrawal of 5-ASA led to partial improvement of renal function. In patients with a delayed diagnosis of kidney damage, recovery of renal function is incomplete and, in some cases, the patient even requires some form of renal replacement therapy. We stress the importance of monitoring renal function in patients diagnosed with inflammatory bowel disease treated with this drug.

Review article: increasing the dose of oral mesalazine therapy for active ulcerative colitis does not improve remission rates

BACKGROUND

Oral mesalazine (mesalamine, 5-aminosalicylic acid) formulations are effective in the treatment of active ulcerative colitis. All formulations contain the same active drug but differ with regard to mechanisms to deliver the drug to the colon. Patients who fail to respond to initial therapy are often administered higher doses of the same formulation.

AIM

To review published trials of oral mesalazine formulations in treating active ulcerative colitis and to examine the effect of dose escalation on remission rates.

RESULTS

Increasing the doses of oral mesalazine formulations does not result in higher remission rates, although increasing the doses of some formulations has been effective in increasing symptomatic improvement and/or response to treatment.

CONCLUSIONS

Because oral mesalazine formulations do not demonstrate a significant dose response with regard to induction of remission of active ulcerative colitis, simple dose escalation may not be the most effective course for patients who fail to respond to initial mesalazine treatment.

A triangulation study of the clinician and patient experiences of the use of the immunosuppressant drugs azathioprine and 6-mercaptopurine for the management of inflammatory bowel disease

AIM

The aim of this study was to explore the service for patients with inflammatory bowel disease taking or having taken azathioprine or 6-mercaptopurine in the last three years, at two District General Hospitals within the same Trust.

BACKGROUND

Published data confirm that the use of azathioprine and 6-mercaptopurine is effective in the control of inflammatory bowel disease. However, there are inconsistencies in dosing regimes, blood monitoring and duration of therapy. Regimes used have been largely based on clinicians' personal preference leading to inconsistencies in practice.

METHODS

A questionnaire, designed to elicit the experience of treatment regimes, blood monitoring and access to information was sent to 130 patients taking or having taken azathioprine or 6-mercaptopurine in the last three years. A further questionnaire was sent to 94 general practitioners and interviews were conducted with 10 hospital doctors initiating treatment.

RESULTS

The study demonstrated lack of clarity in the prescribing methods, the monitoring regimes being offered, variation in information given to patients and consequent patient knowledge.

CONCLUSION

Azathioprine and 6-mercaptopurine are increasingly being used successfully in inflammatory bowel disease, sparing the use of steroids and maintaining remission over a longer period. A review of the current literature has informed and made possible a suggested blood-monitoring regime.

RELEVANCE TO CLINICAL PRACTICE

The adoption of a protocol-led service, managed by the nurse specialist, incorporating guided self-management by patients should be considered. A shared-care approach with the patient and general practitioner with rapid access to secondary care would provide a robust system.

Is there a role for sulfasalazine in the treatment of alopecia areata?

Promising results have been published in the past with the use of sulfasalazine in alopecia areata. We also observed maintenance of hair growth in refractory alopecia areata patients who were treated with sulfasalazine in combination with oral corticosteroids for 2 to 6 months and sulfasalazine alone for 4 to 12 months while steroids were being tapered. We believe that, because of the small series reported herein, additional larger prospective studies should be conducted to validate these results.

5-Aminosalicylates and renal function in inflammatory bowel disease: a systematic review

Nephrotoxicity has been described in some patients with inflammatory bowel disease (IBD) treated with 5-aminosalicylic acid (5-ASA). Studies with 5-ASA treatment in which serum creatinine or creatinine clearance was measured regularly show that nephrotoxicity is exceptional (mean rate of only 0.26% per patient-year). There have been several case reports, including 46 patients, of renal disease associated with 5-ASA treatment in patients with IBD. 5-ASA treatment-related nephrotoxicity is reported most often within the first 12 months, but also delayed presentation after several years has been shown. The absence of a clear relationship between 5-ASA dose and the risk of nephrotoxicity suggests that this complication is idiosyncratic rather than dose-related. Most of the patients with renal disease associated with 5-ASA treatment suffered interstitial nephritis, with symptoms and signs being nonspecific, which may delay detection for many months. The nephrotoxicity potential of mesalazine and sulfasalazine seems to be similar. The risk with different oral preparations of 5-ASA is probably too small to influence the choice of agent. Mesalazine should be withdrawn when renal impairment manifests in a patient with IBD; if this does not result in a fall in serum creatinine, then renal biopsy should be considered. A trial of high-dose steroid may be recommended in patients whose renal function does not respond to drug withdrawal. The optimal monitoring schedule of serum creatinine in patients receiving 5-ASA treatment remains to be established, as there is no evidence to date that either the test, or the frequency of testing, improves patient outcomes.

Azathioprine and 6-mercaptopurine for maintenance of remission in ulcerative colitis

BACKGROUND

Maintenance of remission is a major issue in inflammatory bowel disease. In ulcerative colitis, the evidence for the effectiveness of azathioprine and 6-mercaptopurine for the maintenance of remission is still controversial.

OBJECTIVES

To assess the effectiveness and safety of azathioprine and 6-mercaptopurine for maintaining remission of ulcerative colitis.

SEARCH STRATEGY

The MEDLINE database was used to search literature from 1966 to 2006. A manual search was also performed using references from these articles as well as review articles, proceedings from major gastrointestinal meetings and data available from the Cochrane Collaboration database. Authors of maintenance trials were asked about unpublished studies.

SELECTION CRITERIA

Randomized controlled trials of at least 12 months duration that compared azathioprine or 6-mercaptopurine with placebo or standard maintenance therapy (mesalamine) were included.

DATA COLLECTION AND ANALYSIS

Data were extracted by two raters using standard forms. Disagreements were solved by informal consent, including a third rater. Jadad scores were applied to assess study quality. Analyses were performed separately by type of control (placebo, or active comparator). Pooled odds ratios were calculated based on the fixed effects model unless heterogeneity was shown.

MAIN RESULTS

Six studies were identified including 286 patients with ulcerative colitis. The study quality was mostly poor. Azathioprine was shown to be superior for the maintenance of remission as compared to placebo based on four trials (failure to maintain remission: OR 0.41; 95% CI 0.24 to 0.70). Two trials that compared 6-mercaptopurine to mesalazine, or azathioprine to sulfasalazine showed significant heterogeneity. Both studies using active comparators were open label. Adverse effects occurred in 11 of 127 patients receiving azathioprine, including acute pancreatitis (3 cases) and significant bone marrow suppression (5 cases).

AUTHORS' CONCLUSIONS

Azathioprine may be an effective maintenance therapy for patients who have failed or cannot tolerate mesalazine or sulfasalazine and for patients who require repeated courses of steroids. More research is needed to evaluate superiority over standard maintenance therapy, especially in the light of a potential for adverse events from azathioprine.

Review article: high-dose aminosalicylates to induce and maintain remissions in ulcerative colitis

Sulfasalazine was the first aminosalicylate to be used for induction and maintenance therapy of ulcerative colitis (UC). Initial trials demonstrated a dose response that was compromised by dose-related intolerance. Recognition that the 5-aminosalicylic acid moiety (5-ASA, mesalazine) is the active ingredient of sulfasalazine has allowed the development of sulpha-free formulations of mesalazine and alternative azo-bond derivatives (olsalazine, balsalazide) that substantially reduce the dose-related (and allergic) consequences of the sulfapyridine moiety of sulfasalazine. Dose-ranging studies of mesalazine formulations for induction of remission have demonstrated increased efficacy of oral mesalazine up to 4-4.8 g/day, particularly in patients with more moderate disease activity. Combination therapy with oral and rectal mesalazine provide additional efficacy for patients with both distal and extensive colitis. The mesalazine formulations have dose-related benefits without dose-related side effects. In contrast, the azo-bond formulations are compromised by secretory diarrhoea at doses providing greater than 2-2.4 g/day of mesalazine. There are less data regarding dose-related benefits of aminosalicylates to maintain remissions in UC greater than 1.6 g/day of mesalazine, although the absence of dose-related side effects allows continuation of the same inductive dose through maintenance treatment without dose-related toxicity.

Pharmacoeconomic analyses of azathioprine, methotrexate and prospective pharmacogenetic testing for the management of inflammatory bowel disease

OBJECTIVES

To compare the cost effectiveness of azathioprine (AZA), methotrexate (MTX) and no immunosuppression for maintaining remission of moderate to severe inflammatory bowel disease (IBD) in New Zealand Caucasians, and to determine whether prospective testing for poor metabolisers of AZA by genotype or phenotype is cost effective.

METHODS

Pharmacoeconomic models were developed to compare treatment costs and effects (QALYs) in theoretical populations of 1,000 IBD patients over a 1-year period. Efficacy and tolerability profiles for AZA and MTX were taken from the literature. The costs (year 2004 values) of the drugs and treatment of adverse effects were estimated from New Zealand drug and service costs. Representations of the patients' health-related quality of life (HR-QOL) were obtained from clinicians via the EQ-5D health state classification system and valued using the New Zealand EQ-5D social tariff. The effects of genotyping or phenotyping a population for thiopurine methyltransferase (TPMT) status were compared using the prevalence of TPMT deficiency in Caucasians, the relative risks of neutropenia and the associated costs.

RESULTS

Net cost savings (vs no immunosuppressant treatment) of approximately 2.5 million and 1 million New Zealand dollars were realised for AZA and MTX, respectively, for the theoretical 1,000 patients, and AZA generated 877 QALYs compared with 633 for MTX. Phenotype and genotype testing generated net cost savings (vs no testing) of 120,000 and 11,000 New Zealand dollars, respectively. Savings related to phenotype tests were greater because of the lower assay costs of phenotype testing and a greater likelihood of pre-empting neutropenia.

CONCLUSION

Our model suggests that both MTX and AZA may generate significant net cost savings and benefits for patients with IBD in New Zealand, with AZA likely to be more cost effective than MTX. Prospective testing for poor metabolisers of AZA may also be cost effective, with phenotype testing likely to be more cost effective than genotype testing.

Experience of 5-aminosalicylate nephrotoxicity in the United Kingdom

AIM

To study 5-aminosalicylate nephrotoxicity in patients with inflammatory bowel disease in the UK.

METHODS

A detailed postal questionnaire was sent to all 1298 names in the British Society of Gastroenterology database and 290 consultant members of the Renal Association. The British Society of Gastroenterology reported new cases monthly, the Renal Association 6 monthly. Results were expressed as estimated glomerular filtration rate.

RESULTS

Retrospective study: cases--British Society of Gastroenterology:Renal Association 202:87, aged 15-76 years. Median peak (range) creatinine (British Society of Gastroenterology:Renal Association) - 300:301 (78-1200) micromol/L. Prospective study - 59 cases, median age 52 years (M:F ratio: 47:12). Median pre-treatment estimated glomerular filtration rate: 76.9 (123.9-39), at diagnosis 28.4 (80.5-3.6, creatinine range: 92-1361 micromol/L), recovery 46.8 [111.2-end stage renal failure] mL/min/1.73 m2. Recovery of renal function was significantly improved for patients treated for < 12 months [n = 10, median recovery estimated glomerular filtration rate 70.5 (92-26.9) vs. > 12 months 38.4 (111.2-end stage renal failure) mL/min/1.73 m2, P = 0.028].

CONCLUSIONS

Regular monitoring of renal function may allow earlier detection of nephrotoxicity, particularly during the first year of therapy. Based on an inflammatory bowel disease prevalence in the United Kingdom of 412 x 10(5) with about 50% on treatment, we estimate that the incidence of clinical nephrotoxicity in patients taking 5-aminosalicylate therapy is approximately one in 4000 patients/year.

Review article: monitoring of immunomodulators in inflammatory bowel disease

The armamentarium of medications for the treatment of inflammatory bowel disease is growing and becoming more complicated to use. Immunomodulators are a class of medications that have found a niche for the treatment of Crohn's disease and ulcerative colitis. Because of the mounting supporting evidence for efficacy, the most commonly-used immunomodulators are azathioprine, mercaptopurine, methotrexate and ciclosporin. These medications are being used more often due to their steroid-sparing and potentially surgery-sparing effects. Immunomodulators are also known for a significant side-effect profile and require careful monitoring. This review provides the latest information for clinicians on efficacy, side-effects, dosing and monitoring of these medications for treatment of inflammatory bowel disease.

Pharmacokinetics of budesonide (Entocort EC) capsules for Crohn's disease

This overview summarises available pharmacokinetic data on budesonide capsules (Entocort EC), approved for the treatment of mild-to-moderate active Crohn's disease involving the ileum and/or ascending colon and for prolongation of symptom control. Budesonide is a locally-acting glucocorticosteroid with an extensive, primarily hepatic, metabolism after oral administration. It is rapidly absorbed and biotransformed by cytochrome P450 (CYP) 3A to metabolites with negligible glucocorticoid activity. Entocort EC, a pH- and time-dependent oral formulation of budesonide, was developed to optimise drug delivery to the ileum and throughout the colon. Pharmaco-scintigraphic studies have confirmed that the Entocort EC formulation delays budesonide absorption and prolongs the rate of elimination but maintains complete absorption. This improves the delivery of budesonide to the intestinal lumen relative to a plain formulation. A low systemic availability of 9-21% indicates extensive first-pass elimination. Food appears to have little impact on the absorption of budesonide from Entocort EC capsules and the pharmacokinetics are dose-proportional between 3 and 15 mg. On average, systemic availability was 2.5-fold higher in patients with cirrhosis compared with healthy controls; however, mild liver impairment had little effect on systemic exposure. Pharmacokinetics appear unaffected by gender and age, although this has not been tested in younger children. Renal impairment is not expected to have an impact on the kinetics of Entocort EC. Budesonide is unlikely to inhibit the metabolism of other drugs, including CYP3A4 substrates, mainly because of the very low plasma concentrations obtained with the compound even after high doses of Entocort trade mark EC capsules. Strong CYP3A4 inhibitors, such as ketoconazole, will inhibit the metabolism of budesonide, resulting in several-fold increases in the area under the concentration-time curve of budesonide. Also, grapefruit juice intake may increase systemic availability of budesonide, probably by inhibition of intestinal CYP3A4 activity. Unlike prednisolone, oral contraceptives do not alter plasma budesonide concentrations. An increased pH obtained by gastric acid inhibitory drugs, such as omeprazole, does not affect the pharmacokinetics of budesonide. In summary, budesonide capsules (Entocort EC) possess many pharmacological features that make the formulation well adapted for a targeted treatment of inflammatory disorders, such as Crohn's disease involving the ileum and ascending colon.

Review article: aminosalicylates in inflammatory bowel disease

Aminosalicylate therapy for ulcerative colitis remains a foundational strategy for the induction and maintenance of remission for mild to moderate disease. Although it seems clear that topical mesalazine (mesalamine) is the most efficacious approach to distal ulcerative colitis, recent trials with orally delivered azo conjugates suggest that there may be an advantage over pH-released mesalazine as a first-line approach to active disease. No such comparisons are available for azo products and the prolonged-release formulation, Pentasa. However, recent meta-analyses have demonstrated that, although there is little difference in systemic exposure between marketed products, luminal concentrations may vary. In maintenance therapy, aminosalicylates remain the standard approach after aminosalicylate-induced remission. A number of gaps remain in the evidence base with regard to the optimal dosing of oral mesalazine as a maintenance agent, whether oral mesalazine can maintain remissions after rectal mesalazine induction, and the dose-response and efficacy of aminosalicylates after steroid- or ciclosporin-induced remissions. Although aminosalicylates have been advocated for several decades in Crohn's disease, a number of controversies have evolved since the original trials with sulfasalazine in active Crohn's disease. The original trials demonstrated benefits for sulfasalazine in colonic involvement, but controlled trial evidence for the role of sulfasalazine as maintenance therapy has not been as firmly established. In addition, although oral mesalazine has been demonstrated in controlled trials to be superior to placebo in mild to moderate disease, it is less efficacious than corticosteroids at inducing remissions. The maintenance benefits of mesalazine appear to be limited to patients 'induced into remission' with mesalazine and in some post-operative settings.

Thiopurine methyltransferase (TPMT) genotype distribution in azathioprine-tolerant and -intolerant patients with various disorders. The impact of TPMT genotyping in predicting toxicity

OBJECTIVE

To study the distribution of the thiopurine methyltransferase (TPMT) genotype among azathioprine (Aza)-tolerant and -intolerant patients with various disorders, and to investigate a possible relationship with the Aza metabolite levels.

METHODS

Forty-six Aza-tolerant and six Aza-intolerant patients had the TPMT genotype distribution determined using a polymerase chain reaction (PCR) assay and the forty-six Aza-tolerant patients had the Aza metabolite levels determined using a high-pressure liquid chromatography (HPLC) analysis.

RESULTS

One non-functional TPMT mutant allele was demonstrated in 2 of the 46 Aza-tolerant patients (4.4%) and one or two non-functional mutant alleles in 2 of the 6 Aza-intolerant patients (33.3%). Of the 4 patients, with one or two non-functional mutant alleles 2 (50%) were intolerant to Aza compared with 4 of the 48 patients (8.3%) with no mutations detected. The time to hepatotoxicity did not differ significantly between the 2 patients with one or two non-functional mutant alleles and the remaining 3 patients ( P=0.5). The TPMT genotype distribution differed slightly in the three different categories of disorders ( P=0.05). The median E-6-TGN level among the 2 TPMT heterozygous patients was 275 pmol/8x10(8) RBC (range 240-310), whereas the remaining 44 patients had a median E-6-TGN level of 110 pmol/8x10(8) RBC (range 0-440) ( P=0.07).

CONCLUSION

Although TPMT genotyping cannot be recommended on behalf of the present study, it is to be expected that half of the patients with one or two non-functional TPMT mutant alleles will develop Aza intolerance leading to withdrawal of therapy. Thus, clinicians may anticipate about 5% of the patients to develop intolerance to Aza therapy solely for that reason.