Bioavailability of 5-aminosalicyclic acid from slow release 5-aminosalicyclic acid drug and sulfasalazine in normal children

Diagnosis by Microbial Culture, Breath Tests and Urinary Excretion Tests, and Treatments of Small Intestinal Bacterial Overgrowth

Small intestinal bacterial overgrowth (SIBO) is characterized as the increase in the number and/or alteration in the type of bacteria in the upper gastrointestinal tract and accompanies various bowel symptoms such as abdominal pain, bloating, gases, diarrhea, and so on. Clinically, SIBO is diagnosed by microbial culture in duodenum/jejunum fluid aspirates and/or the breath tests (BT) of hydrogen/methane gases after ingestion of carbohydrates such as glucose. The cultural analysis of aspirates is regarded as the golden standard for the diagnosis of SIBO; however, this is invasive and is not without risk to the patients. BT is an inexpensive and safe diagnostic test but lacks diagnostic sensitivity and specificity depending on the disease states of patients. Additionally, the urinary excretion tests are used for the SIBO diagnosis using chemically synthesized bile acid conjugates such as cholic acid (CA) conjugated with para-aminobenzoic acid (PABA-CA), ursodeoxycholic acid (UDCA) conjugated with PABA (PABA-UDCA) or conjugated with 5-aminosalicylic acid (5-ASA-UDCA). These conjugates are split by bacterial bile acid (cholylglycine) hydrolase. In the tests, the time courses of the urinary excretion rates of PABA or 5-ASA, including their metabolites, are determined as the measure of hydrolytic activity of intestinal bacteria. Although the number of clinical trials with this urinary excretion tests is small, results demonstrated the usefulness of bile acid conjugates as SIBO diagnostic substrates. PABA-UDCA disulfate, a single-pass type unabsorbable compound without the hydrolysis of conjugates, was likely to offer a simple and rapid method for the evaluation of SIBO without the use of radioisotopes or expensive special apparatus. Treatments of SIBO with antibiotics, probiotics, therapeutic diets, herbal medicines, and/or fecal microbiota transplantation are also reviewed.

Management of Paediatric Ulcerative Colitis, Part 1: Ambulatory Care-An Evidence-based Guideline From European Crohn's and Colitis Organization and European Society of Paediatric Gastroenterology, Hepatology and Nutrition

BACKGROUND

The contemporary management of ambulatory ulcerative colitis (UC) continues to be challenging with ∼20% of children needing a colectomy within childhood years. We thus aimed to standardize daily treatment of pediatric UC and inflammatory bowel diseases (IBD)-unclassified through detailed recommendations and practice points.

METHODS

These guidelines are a joint effort of the European Crohn's and Colitis Organization (ECCO) and the Paediatric IBD Porto group of European Society of Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN). An extensive literature search with subsequent evidence appraisal using robust methodology was performed before 2 face-to-face meetings. All 40 included recommendations and 86 practice points were endorsed by 43 experts in Paediatric IBD with at least an 88% consensus rate.

RESULTS

These guidelines discuss how to optimize the use of mesalamine (including topical), systemic and locally active steroids, thiopurines and, for more severe disease, biologics. The use of other emerging therapies and the role of surgery are also covered. Algorithms are provided to aid therapeutic decision-making based on clinical assessment and the Paediatric UC Activity Index (PUCAI). Advice on contemporary therapeutic targets incorporating the use of calprotectin and the role of therapeutic drug monitoring are presented, as well as other management considerations around pouchitis, extraintestinal manifestations, nutrition, growth, psychology, and transition. A brief section on disease classification using the PIBD-classes criteria and IBD-unclassified is also part of these guidelines.

CONCLUSIONS

These guidelines provide a guide to clinicians managing children with UC and IBD-unclassified management to provide modern management strategies while maintaining vigilance around appropriate outcomes and safety issues.

Consensus guidelines of ECCO/ESPGHAN on the medical management of pediatric Crohn's disease

Children and adolescents with Crohn's disease (CD) present often with a more complicated disease course compared to adult patients. In addition, the potential impact of CD on growth, pubertal and emotional development of patients underlines the need for a specific management strategy of pediatric-onset CD. To develop the first evidenced based and consensus driven guidelines for pediatric-onset CD an expert panel of 33 IBD specialists was formed after an open call within the European Crohn's and Colitis Organisation and the European Society of Pediatric Gastroenterolog, Hepatology and Nutrition. The aim was to base on a thorough review of existing evidence a state of the art guidance on the medical treatment and long term management of children and adolescents with CD, with individualized treatment algorithms based on a benefit-risk analysis according to different clinical scenarios. In children and adolescents who did not have finished their growth, exclusive enteral nutrition (EEN) is the induction therapy of first choice due to its excellent safety profile, preferable over corticosteroids, which are equipotential to induce remission. The majority of patients with pediatric-onset CD require immunomodulator based maintenance therapy. The experts discuss several factors potentially predictive for poor disease outcome (such as severe perianal fistulizing disease, severe stricturing/penetrating disease, severe growth retardation, panenteric disease, persistent severe disease despite adequate induction therapy), which may incite to an anti-TNF-based top down approach. These guidelines are intended to give practical (whenever possible evidence-based) answers to (pediatric) gastroenterologists who take care of children and adolescents with CD; they are not meant to be a rule or legal standard, since many different clinical scenario exist requiring treatment strategies not covered by or different from these guidelines.

Management of pediatric ulcerative colitis: joint ECCO and ESPGHAN evidence-based consensus guidelines

BACKGROUND AND AIMS

Pediatric ulcerative colitis (UC) shares many features with adult-onset disease but there are some unique considerations; therefore, therapeutic approaches have to be adapted to these particular needs. We aimed to formulate guidelines for managing UC in children based on a systematic review (SR) of the literature and a robust consensus process. The present article is a product of a joint effort of the European Crohn's and Colitis Organization (ECCO) and the European Society for Paediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN).

METHODS

A group of 27 experts in pediatric IBD participated in an iterative consensus process including 2 face-to-face meetings, following an open call to ESPGHAN and ECCO members. A list of 23 predefined questions were addressed by working subgroups based on a SR of the literature.

RESULTS

A total of 40 formal recommendations and 68 practice points were endorsed with a consensus rate of at least 89% regarding initial evaluation, how to monitor disease activity, the role of endoscopic evaluation, medical and surgical therapy, timing and choice of each medication, the role of combined therapy, and when to stop medications. A management flowchart, based on the Pediatric Ulcerative Colitis Activity Index (PUCAI), is presented.

CONCLUSIONS

These guidelines provide clinically useful points to guide the management of UC in children. Taken together, the recommendations offer a standardized protocol that allows effective, timely management and monitoring of the disease course, while acknowledging that each patient is unique.

Systematic review of the evidence base for the medical treatment of paediatric inflammatory bowel disease

OBJECTIVE

To systematically review the evidence base for the medical (pharmaceutical and nutritional) treatment of paediatric inflammatory bowel disease.

METHODS

Key clinical questions were formulated regarding different treatment modalities used in the treatment of paediatric (not adult-onset) IBD, in particular the induction and maintenance of remission in Crohn disease and ulcerative colitis. Electronic searches were performed from January 1966 to December 2006, using the electronic search strategy of the Cochrane IBD group. Details of papers were entered on a dedicated database, reviewed in abstract form, and disseminated in full for appraisal. Clinical guidelines were appraised using the AGREE instrument and all other relevant papers were appraised using Scottish Intercollegiate Guidelines Network methodology, with evidence levels given to all papers.

RESULTS

A total of 6285 papers were identified, of which 1255 involved children; these were entered on the database. After critical appraisal, only 103 publications met our criteria as evidence on medical treatment of paediatric IBD. We identified 3 clinical guidelines, 1 systematic review, and 16 randomised controlled trials; all were of variable quality, with none getting the highest methodological scores.

CONCLUSIONS

This is the first comprehensive review of the evidence base for the treatment of paediatric IBD, highlighting the paucity of trials of high methodological quality. As a result, the development of clinical guidelines for managing children and young people with IBD must be consensus based, informed by the best-available evidence from the paediatric literature and high-quality data from the adult IBD literature, together with the clinical expertise and multidisciplinary experience of paediatric IBD experts.

5-ASA affects cell cycle progression in colorectal cells by reversibly activating a replication checkpoint

BACKGROUND & AIMS

Individuals with inflammatory bowel disease are at risk of developing colorectal cancer (CRC). Epidemiologic, animal, and laboratory studies suggest that 5-amino-salicylic acid (5-ASA) protects from the development of CRC by altering cell cycle progression and by inducing apoptosis. Our previous results indicate that 5-ASA improves replication fidelity in colorectal cells, an effect that is active in reducing mutations. In this study, we hypothesized that 5-ASA restrains cell cycle progression by activating checkpoint pathways in colorectal cell lines, which would prevent tumor development and improve genomic stability.

METHODS

CRC cells with different genetic backgrounds such as HT29, HCT116, HCT116(p53-/-), HCT116+chr3, and LoVo were treated with 5-ASA for 2-96 hours. Cell cycle progression, phosphorylation, and DNA binding of cell cycle checkpoint proteins were analyzed.

RESULTS

We found that 5-ASA at concentrations between 10 and 40 mmol/L affects cell cycle progression by inducing cells to accumulate in the S phase. This effect was independent of the hMLH1, hMSH2, and p53 status because it was observed to a similar extent in all cell lines under investigation. Moreover, wash-out experiments demonstrated reversibility within 48 hours. Although p53 did not have a causative role, p53 Ser15 was strongly phosphorylated. Proteins involved in the ATM-and-Rad3-related kinase (ATR)-dependent S-phase checkpoint response (Chk1 and Rad17) were also phosphorylated but not ataxia telengectasia mutated kinase.

CONCLUSIONS

Our data demonstrate that 5-ASA causes cells to reversibly accumulate in S phase and activate an ATR-dependent checkpoint. The activation of replication checkpoint may slow down DNA replication and improve DNA replication fidelity, which increases the maintenance of genomic stability and counteracts carcinogenesis.

Metabolic and pharmacological properties of rutin, a dietary quercetin glycoside, for treatment of inflammatory bowel disease

PURPOSE

Orally administered rutin reportedly ameliorates 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis of rats. We investigated the metabolic and pharmacological properties of rutin underlying the rutin-mediated amelioration of the rat colitis.

METHODS

Apparent partition coefficients of rutin and its aglycone quercetin were compared. The biochemical/chemical stability of rutin was examined in the contents of various segments of gastrointestinal tracts of rats. Inflammatory indices were determined in the colitis rats after oral administration of rutin or rectal administration of quercetin. In human colon epithelial cells, the effect of quercetin on tumor necrosis factor-alpha (TNF-alpha)-induced nuclear factor kappa B (NFkappaB) activation was examined.

RESULTS

The sugar residue in rutin greatly lowered the apparent partition coefficient and was rapidly deglycosylated to liberate quercetin in the cecal contents, whereas it was stable in the contents of the upper intestine. Not only oral administration of rutin but also rectal administration of quercetin remarkably ameliorated TNBS-induced colitis rats, indicating that quercetin liberated from rutin is therapeutically active. Furthermore, quercetin dose-dependently inhibited an inflammatory signal TNF-alpha-dependent NFkappaB activation.

CONCLUSIONS

Our data suggest that rutin acted as a quercetin deliverer to the large intestine and its anti-inflammatory action in TNBS-induced colitis rats may be through quercetin-mediated inhibition of TNF-alpha-induced NFkappaB activation.

Pharmacokinetics of mesalazine pellets in children with inflammatory bowel disease

Mesalazine is a first-line drug in pediatric inflammatory bowel disease (IBD), and is customarily used to induce and maintain remission in mild to moderate disease. In children, pharmacokinetic data are scarce, and dosage recommendations are largely extrapolated from studies in adults. Aim of the study was to obtain the pharmacokinetic profile of a new mesalazine pellet formulation in children with ulcerative colitis and Crohn's colitis. A single oral dose of 20 mg/kg mesalazine was administered to 13 patients (age 6-16 years). Serial blood and urine sampling for determination of mesalazine and acetylmesalazine was performed before and during 24 hours following ingestion. Maximum plasma concentration of mesalazine (Cmax) was 1332 ng/mL (geometric mean, geometric coefficient of variation [CV]: 0.57), obtained 3.7 hours (tmax; CV: 0.31) after drug administration. Systemic exposure as determined by area under the plasma concentration-time curve (AUC(0-infinity) ) was 8712 ng/ml*h (CV: 0.44). Terminal half-life of elimination of mesalazine was 3.5 hours (t(1/2); CV: 1.43). This study presents extensive pharmacokinetic data on mesalazine in children with mild-moderately active ulcerative colitis and Crohn's colitis. In comparison with previous experience in adults, pharmacokinetics of mesalazine administered as pellets appear to be similar in both populations.

Treatment of inflammatory bowel disease in childhood: best available evidence

The physician treating children with inflammatory bowel disease is confronted with a number of specific problems, one of them being the lack of randomized, controlled drug trials in children. In this review, the role of nutritional therapy is discussed with a focus on primary treatment, especially for children with Crohn's disease. Then, the available medical therapies are highlighted, reviewing the evidence of effectiveness and side effects in children, as compared with what is known in adults. Nutritional therapy has proven to be effective in inducing and maintaining remission in Crohn's disease while promoting linear growth. Conventional treatment consists of aminosalicylates and corticosteroids, whereas the early introduction of immunosuppressives (such as azathioprine or 6-mercaptopurine) is advocated as maintenance treatment. If these drugs are not tolerated or are ineffective, methotrexate may serve as an alternative in Crohn's disease. Cyclosporine is an effective rescue therapy in severe ulcerative colitis, but only will postpone surgery. A novel strategy to treat Crohn's disease is offered by infliximab, a monoclonal antibody to the proinflammatory cytokine tumor necrosis factor (TNF)-alpha. Based on the best-available evidence, suggested usage is provided for separate drugs with respect to dosage and monitoring of side effects in children.

Clinical pharmacokinetics of slow release mesalazine

Slow release oral mesalazine (Pentasa) contains microgranules covered by a semipermeable ethylcellulose membrane. The microgranules continuously release their content from duodenum to ileum in a pH- and time-dependent way. About 75% of the microgranules pass into the colon, where further release is slower. This release pattern does not appear to be affected by food, diarrhoea or the simultaneous use of H2 antagonists. Rectal forms of mesalazine deliver active drug directly to the rectum and left colon. Plasma concentrations of mesalazine and its metabolite acetyl-5-aminosalicylic acid after oral or local administration are the result of systemic absorption and hepatic metabolism by N-acetyltransferase. Most studies report maximal plasma concentrations of less than 1 mg/L after oral administration of slow release mesalazine, much lower than those observed after uncoated mesalazine but generally higher than after azo-bound drugs such as sulfasalazine. Urinary recovery is an indicator of absorption and metabolism, and is lower after rectal administration (10 to 30%) than after oral administration (30 to 40%). Faecal recovery after oral administration of slow or delayed release mesalazine is lower than with azo-bound drugs. Mesalazine acts locally after absorption by colonic and ileal mucosa. Mean steady-state concentrations of 25.7+/-2.2 microg/kg wet weight are found in ileocolonic biopsy specimens from patients with irritable bowel syndrome treated for 1 week with slow release mesalazine 1.5 g/day. Intramucosal concentrations after slow release mesalazine differ little between healthy individuals and patients with inflammatory bowel disease. Although significant differences are found between the various aminosalicylates in release patterns and the resulting pharmacokinetic parameters, no differences in therapeutic effects have been found in comparative studies. High doses of oral mesalazine (2 to 4 g/day) are more effective than lower doses in the treatment of patients with mild to moderate active ulcerative colitis. High doses (4 g/day) are also effective in the treatment of Crohn's disease, predominantly in patients with ileitis. In contrast, no dose ranging effects were demonstrated with local treatment forms: mesalazine 1g enema seems sufficient for patients with distal colitis. Higher serum concentrations and urinary recoveries after the administration of slow or delayed release mesalazine compared with azo-bound drugs suggest a higher risk for renal adverse effects, although the reported occurrence is extremely low. Although preliminary data support an association between mucosal concentrations of mesalazine and its clinical activity, further studies are needed to correlate the effects of this drug with its pharmacokinetic parameters.

Cholestasis associated with mesalazine therapy in a patient with Crohn's disease

BACKGROUND/AIMS

Mesalazine is a widely prescribed medication, developed as an alternative to sulfasalazine in the treatment of inflammatory bowel disease. In contrast to sulfasalazine, there are only a few case reports on its causing hepatic injury. We here report on a patient with cholestasis after mesalazine therapy for Crohn's disease of the ileum.

METHODS/RESULTS

The patient, a 30-year-old man, developed clinical signs of severe hepatic injury 4 months after treatment with mesalazine (4 g/day) including biopsy-proven hepatocellular cholestasis with minimal focal mononuclear inflammatory infiltration. Contrary to previous reports, no symptoms of generalized hypersensitivity were seen. The patient's illness was resolved by discontinuing the mesalazine treatment and he recovered completely in 40 days.

CONCLUSIONS

This case reinforces the possibility of a causal relationship between mesalazine treatment and toxic hepatic injury without systemic hypersensitivity.

Comparative bioavailability of 5-aminosalicylic acid from a controlled release preparation and an azo-bond preparation

BACKGROUND

Knowledge of the bioavailability of 5-aminosalicylic acid (5-ASA, mesalazine) from the different 5-ASA-containing drugs is important for rational therapy of inflammatory bowel diseases.

METHODS

The local and systemic bioavailability of 5-ASA from a controlled release 5-ASA preparation (Pentasa--2, 4 or 6 g/day) was investigated and compared with the azo-bond 5-ASA preparation olsalazine (Dipentum--2 g/day) in 13 healthy volunteers during steady state conditions.

RESULTS

The therapeutically relevant parameter of 5-ASA at the rectal level, expressed as the mean concentration in faecal water, showed a significant trend towards higher concentrations with increasing Pentasa dose: 9.2 mmol/L, 19.0 mmol/L and 24.4 mmol/L, respectively. The concentration of olsalazine 2 g/day was 16.0 mmol/L. The concentration of the metabolite N-acetyl-5-aminosalicylic acid (Ac-5-ASA) did not rise with increasing Pentasa dose, indicating saturable presystemic acetylating capacity of 5-ASA. Total urinary excretion of 5-ASA and Ac-5-ASA, as a percentage of the daily ingested 5-ASA dose, remained constant on the three Pentasa doses, but there was a significant increase in the 5-ASA fraction. Mean steady state plasma concentrations of 5-ASA and Ac-5-ASA were significantly higher on Pentasa 4 g/day and 6 g/day than on 2 g/day. Values on Pentasa 2 g/day were comparable with those on olsalazine 2 g/day.

CONCLUSIONS

The study confirmed that 5-ASA is released from Pentasa in a predictable manner, the amount released increasing with dose. Olsalazine is an excellent generator of 5-ASA in the colon.