Olsalazine is not superior to placebo in maintaining remission of inactive Crohn's colitis and ileocolitis: a double blind, parallel, randomised, multicentre study

A review of the therapeutic management of Crohn's disease

Crohn's disease is a chronic inflammatory, relapsing-remitting, and progressive gastrointestinal disorder with an often-negative impact on the physical, emotional, and psychological well-being. Over the past two decades, the medical compendium for the treatment of Crohn's disease has increased significantly, enabling treatment beyond symptoms. Indeed, early and timely use of effective medical therapy has been reflected by improved outcomes with reduction in surgery and ability to achieve clinical and endoscopic remission, reduce corticosteroid dependance, and prevent long-term complications in more patients. In this review, we discuss the key milestones in the medical management of Crohn's disease.

Oral 5-aminosalicylic acid for maintenance of surgically-induced remission in Crohn's disease

BACKGROUND

Crohn's disease (CD) is a chronic inflammatory disorder that can involve any part of the gastrointestinal tract. 5-Aminosalicylates (5-ASAs) are locally acting, anti-inflammatory compounds that reduce inflammation of the colonic mucosa with release profiles that vary among various commercially available formulations. This updated Cochrane review summarizes current evidence on the use of 5-ASA formulations for maintenance of surgically-induced remission in CD.

OBJECTIVES

To assess the efficacy and safety of 5-ASA agents for the maintenance of surgically-induced remission in CD.

SEARCH METHODS

We searched MEDLINE, Embase, CENTRAL, the Cochrane IBD Group Specialized Register from inception to 16 July 2018. We also searched references, conference abstracts, and trials registers.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that included participants with CD in remission following surgery and compared 5-ASAs to no treatment, placebo or any other active intervention with duration of at least three months were considered for inclusion.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. The primary outcome was clinical relapse. Secondary outcomes included endoscopic recurrence, radiologic and surgical relapse, adverse events, serious adverse events and withdrawal due to adverse events.

MAIN RESULTS

Fourteen RCTs (1867 participants) were included in the review. Participants (15 to 70 years) were recruited from gastroenterology hospitals and medical clinics in Europe and North America and followed up between 3 and 72 months. The risk of bias was assessed as 'low' in one study, 'unclear' in seven and as 'high' in six.At 12 months, 36% (20/55) of participants in the 5-ASA group experienced clinical relapse compared to 51% (28/55) in the no treatment control group (RR 0.71, 95% CI 0.46 to 1.10; low certainty evidence). Moderate certainty evidence suggests that 5-ASAs are more effective for preventing clinical relapse than placebo. During a follow-up period of 12 to 72 months, 36% (131/361) of 5-ASA participants relapsed compared to 43% (160/369) of placebo participants (RR 0.83, 95% CI 0.72 to 0.96; I² = 0%; moderate certainty evidence). At 12 months, 17% (17/101) of the 4 g/day mesalamine group relapsed compared to 26% (27/105) of the 2.4 g/day group (RR 0.65, 95% CI 0.38 to 1.13; moderate certainty evidence). There was no evidence of a difference in clinical relapse rates when 5-ASA compounds were compared to purine antimetabolites. At 24 months, 61% (103/170) of mesalamine participants relapsed compared to 67% (119/177) of azathioprine participants (RR 0.90, 95% CI 0.76 to 1.07; I² = 28%; low certainty evidence). During 24 months, 50% (9/18) of 5-ASA participants had clinical relapse compared to 13% (2/16) of adalimumab participants (RR 4.0, 95% CI 1.01 to 15.84; low certainty evidence). The effects of sulphasalazine compared to placebo on clinical relapse rate is uncertain. After 18 to 36 months, 66% (95/143) of participants treated with sulphasalazine relapsed compared to 71% (110/155) in the placebo group (RR 0.88, 95% CI 0.56 to 1.38; I² = 38%; low certainty evidence).The effect of 5-ASA drugs on safety was uncertain. During 24 months follow-up, 4% (2/55) of 5-ASA participants experienced adverse events compared to none (0/55) in the no treatment control group (RR 5.00, 95% CI 0.25 to 101.81; very low certainty evidence). An equal proportion of 5-ASA participants (10%; 23/241) and placebo (9%; 20/225) groups experienced an adverse event during a follow-up of 3 to 72 months (RR 1.07, 95% CI 0.60 to 1.91; I² = 0%; low certainty evidence). Adverse event rates were similar in the 5-ASA and purine analogues groups. However, serious adverse events and withdrawals due to adverse events were more common in participants who received purine analogues than 5-ASA. At 52 weeks to 24 months, 52% (107/207) of 5-ASA participants had an adverse event compared to 47% (102/218) of purine analogue participants (RR 1.11, 95% CI 0.97 to 1.27, I² = 0%; low certainty evidence). Four per cent (6/152) of 5-ASA participants had a serious adverse event compared to 17% (27/159) of purine analogue participants (RR 0.30, 95% CI 0.11 to 0.80; very low certainty evidence). Eight per cent (17/207) of 5-ASA participants withdrew due to an adverse event compared to 19% (42/218) of purine analogue participants (RR 0.48, 95% CI 0.28 to 0.83; low certainty evidence). Adverse event rates were similar in high and low dose mesalamine participants. After 12 months, 2% (2/101) of 4 g/day mesalamine participants had an adverse event compared to 2% (2/105) of 2.4 g/day participants (RR 1.04, 95% CI 0.15 to 7.24; low certainty evidence). The proportion of participants who experienced adverse events over a 24 month follow-up in the mesalamine group was 78% (14/18) compared to 69% (11/16) of adalimumab participants (RR 1.13, 95% CI 0.75 to 1.71; very low certainty evidence). None (0/32) of the sulphasalazine participants had an adverse event at 18 months follow-up compared to 3% (1/34) of the placebo group (RR 0.35, 95% CI 0.01 to 8.38; very low certainty evidence). Commonly reported adverse events in the included studies were diarrhoea, nausea, increased liver function tests, pancreatitis, and abdominal pain.

AUTHORS' CONCLUSIONS

5-ASA preparations are superior to placebo for the maintenance of surgically-induced clinical remission in patients with CD (moderate certainty). The number needed to treat to prevent one relapse was 13 patients. The evidence for endoscopic remission is uncertain. The sulphasalazine class of 5-ASA agents failed to demonstrate superiority against placebo, 5-ASAs failed to demonstrate superiority compared to no treatment (very low and low certainty). The efficacy of two different doses of the same 5-ASA and the efficacy of 5-ASA compared to purine antimetabolites (azathioprine or 6-mercaptopurine) in maintaining surgically-induced remission of CD remains unclear. However, purine analogues lead to more serious adverse events and discontinuation due to adverse events. There is a low certainty that 5-ASA is inferior for maintaining surgically-induced remission of CD compared to biologics (anti TNF-ɑ). 5-ASA formulations appear to be safe with no difference in the occurrence of adverse events or withdrawal when compared with placebo, no treatment or biologics.

Systematic review: outcomes and adverse events from randomised trials in Crohn's disease

BACKGROUND

The suitability of disease activity indices has been challenged, with growing interest in objective measures of inflammation.

AIM

To undertake a systematic review of efficacy and safety outcomes in placebo-controlled randomised controlled trials (RCTs) of patients with Crohn's disease.

METHODS

MEDLINE, EMBASE, CINAHL and Cochrane Library were searched until November 2015, for RCTs of adult Crohn's disease patients treated with medical or surgical therapies. Data on efficacy and safety outcomes, end-point definitions, and measurement instruments were extracted and stratified by publication date (pre-2009 and 2009 onwards).

RESULTS

One hundred and eighty-one RCTs (110 induction and 71 maintenance) were identified, including 23 850 patients. About 92.3% reported clinical efficacy endpoints. The Crohn's Disease Activity Index (CDAI) dominated, defining clinical response or remission in 63.5% of trials (35 definitions of response or remission). CDAI < 150 was the commonest endpoint, but reporting reduced between periods (46.4%-41.1%), whilst use of CDAI100 increased (16.8%-30.4%). Fistula studies most commonly reported fistula closure (9, 90.0%). Reporting of biomarker, endoscopy and histology endpoints increased overall (33.3%-40.6%, 14.4%-30.4% and 3.2%-12.5%, respectively), but were heterogeneous and rarely reported in fistula trials. Patient-reported outcome measures were reported in 41.4% of trials and safety endpoints in 35.4%. Many of the common adverse events relate to disease exacerbation or treatment failure.

CONCLUSIONS

Trial endpoints vary across studies, over time and are distinct in fistula studies. Despite growth in reporting of objective measures of inflammation and in patient-reported outcome measures, there is a lack of standardisation. This confirms the need for a core outcome set for comparative effectiveness research in Crohn's disease.

ACG Clinical Guideline: Management of Crohn's Disease in Adults

Crohn's disease is an idiopathic inflammatory disorder of unknown etiology with genetic, immunologic, and environmental influences. The incidence of Crohn's disease has steadily increased over the past several decades. The diagnosis and treatment of patients with Crohn's disease has evolved since the last practice guideline was published. These guidelines represent the official practice recommendations of the American College of Gastroenterology and were developed under the auspices of the Practice Parameters Committee for the management of adult patients with Crohn's disease. These guidelines are established for clinical practice with the intent of suggesting preferable approaches to particular medical problems as established by interpretation and collation of scientifically valid research, derived from extensive review of published literature. When exercising clinical judgment, health-care providers should incorporate this guideline along with patient's needs, desires, and their values in order to fully and appropriately care for patients with Crohn's disease. This guideline is intended to be flexible, not necessarily indicating the only acceptable approach, and should be distinguished from standards of care that are inflexible and rarely violated. To evaluate the level of evidence and strength of recommendations, we used the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. The Committee reviews guidelines in depth, with participation from experienced clinicians and others in related fields. The final recommendations are based on the data available at the time of the production of the document and may be updated with pertinent scientific developments at a later time.

Recent advances in clinical practice: a systematic review of isolated colonic Crohn's disease: the third IBD?

The genetics of isolated colonic Crohn's disease place it approximately midway between Crohn's disease with small intestinal involvement and UC, making a case for considering it as a separate condition. We have therefore systematically reviewed its epidemiology, pathophysiology and treatment. Key findings include a higher incidence in females (65%) and older average age at presentation than Crohn's disease at other sites, a mucosa-associated microbiota between that found in ileal Crohn's disease and UC, no response to mesalazine, but possibly better response to antitumour necrosis factor than Crohn's disease at other sites. Diagnostic distinction from UC is often difficult and also needs to exclude other conditions including ischaemic colitis, segmental colitis associated with diverticular disease and tuberculosis. Future studies, particularly clinical trials, but also historical cohorts, should assess isolated colonic Crohn's disease separately.

Bovine lactoferrin and Crohn's disease: a case study

A 22-year-old male suffering from abdominal pain, repeated diarrhea, and weight loss visited the Digestive Disease Department of Nagoya City University Hospital on 19 December 2011. He was hospitalized and diagnosed with Crohn's colitis. His Crohn's Disease Activity Index (CDAI) was 415. Treatment by granulocyte apheresis, mesalazine, and adalimumab was started. His CDAI was 314 on 30 December and 215 on 5 January. A colonoscopic examination on 19 January showed almost complete remission in the transverse colon and marked remission in the rectum. Mesalazine therapy was stopped on 28 February, and the patient was instructed to self-inject 40 mg of adalimumab every other week. His CDAI was 50 on 10 April, indicating clinical remission. His last self-injection of adalimumab was on 24 April 2012, and he started taking 1 g of bovine lactoferrin (bLF) daily. His CDAI was 35 on 8 January 2013. He continued taking 1 g of bLF daily without any other treatment for Crohn's disease. Laboratory blood tests on 7 September 2015 showed no sign of disease recurrence, and a colonoscopic examination on 23 October 2015 showed almost complete mucosal healing. This case indicates that ingestion of bLF to maintain Crohn's disease in a remissive state should be further explored.

Oral 5-aminosalicylic acid for maintenance of medically-induced remission in Crohn's disease

BACKGROUND

The prevention of relapse is a major issue in the management of Crohn's disease. Corticosteroids, the mainstay of treatment of acute exacerbations, are not effective for maintenance of remission and its chronic use is limited by numerous adverse events. Randomised controlled trials assessing the efficacy of oral 5-aminosalicylic acid (5-ASA) agents for maintenance of medically-induced remission in Crohn's disease have produced conflicting results.

OBJECTIVES

To conduct a systematic review to evaluate the efficacy and safety of oral 5-ASA agents for the maintenance of medically-induced remission in Crohn's disease.

SEARCH METHODS

We searched MEDLINE, EMBASE, CENTRAL and the IBD Group Specialized Register from inception to 8 June 2016. We also searched reference lists and conference proceedings.

SELECTION CRITERIA

We included randomised controlled trials that compared oral 5-ASA agents to either placebo or sulphasalazine in patients with quiescent Crohn's disease. The trials had to have a treatment duration of at least six months.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and performed the risk of bias assessment. Any disagreements were resolved by discussion and consensus. The primary outcome measure was the occurrence of relapse as defined by the primary studies. Secondary outcomes included time to relapse, adverse events, withdrawal due to adverse events and serious adverse events. We calculated the pooled risk ratio (RR) and corresponding 95% confidence interval (95% CI) using a fixed-effect model. All data were analysed on an intention-to-treat basis and drop-outs were considered to be relapses. Sensitivity analyses included an available case analysis where drop-outs were ignored and using a random-effects model. We evaluated the overall quality of the evidence supporting the outcomes using the GRADE criteria.

MAIN RESULTS

Twelve studies (2146 participants) that compared 5-ASA to placebo were included. We did not identify any studies that compared sulphasalazine to placebo. Seven studies were judged to be at low risk of bias. The other studies were judged to have an unclear risk of bias for various items due to insufficient details to allow for a judgement. There was no statistically significant difference in relapse rates at 12 months. Fifty-three per cent (526/998) of 5-ASA patients (dose 1.6 g to 4 g/day) relapsed at 12 months compared to 54% (544/1016) of placebo patients (RR 0.98, 95% CI 0.91 to 1.07; 11 studies; 2014 patients; moderate-quality evidence). Sensitivity analyses based on an available case analysis and a random-effects model had no impact on the results. One study found no difference in relapse rates at 24 months. Fifty-four per cent (31/57) of 5-ASA patients (dose 2 g/day) relapsed at 24 months compared to 58% (36/62) of placebo patients (RR 0.94, 95% CI 0.68 to 1.29, 119 patients; low-quality evidence). One paediatric study found no statistically significant difference in relapse rates at 12 months. Sixty-two per cent (29/47) of paediatric 5-ASA patients (dose 50 mg/kg/day) relapsed at 12 months compared to 64% (35/55) of paediatric placebo patients (RR 0.97, 95% CI 0.72 to 1.31; 102 patients; moderate-quality evidence). There was no statistically significant difference in the proportion of patients who experienced an adverse event, withdrawal due to adverse events or serious adverse events. Thirty-four per cent (307/900) of 5-ASA patients had at least one adverse event compared to 33% (301/914) of placebo patients (RR 1.05, 95% CI 0.95 to 1.17; 10 studies; 1814 patients). Fourteen per cent (127/917) of 5-ASA patients withdrew due to adverse events compared to 13% (119/916) of placebo patients (RR 1.11, 95% CI 0.88 to 1.38; 9 studies; 1833 patients). One per cent (3/293) of 5-ASA patients had a serious adverse event compared to 0.7% (2/283) of placebo patients (RR 1.43, 95% CI 0.24 to 2.83; 3 studies; 576 patients). Common adverse events reported in the studies included diarrhoea, nausea and vomiting, abdominal pain, headache and skin rash.

AUTHORS' CONCLUSIONS

We found no evidence in this review to suggest that oral 5-ASA preparations are superior to placebo for the maintenance of medically-induced remission in patients with Crohn's disease. Additional randomised trials may not be justified.

Aminosalicylates for induction of remission or response in Crohn's disease

BACKGROUND

Randomized trials investigating the efficacy of aminosalicylates for the treatment of mildly to moderately active Crohn's disease have yielded conflicting results. A systematic review was conducted to critically examine current available data on the efficacy of sulfasalazine and mesalamine for inducing remission or clinical response in these patients.

OBJECTIVES

To evaluate the efficacy of aminosalicylates compared to placebo, corticosteroids, and other aminosalicylates (alone or in combination with corticosteroids) for the treatment of mildly to moderately active Crohn's disease.

SEARCH METHODS

We searched PubMed, EMBASE, MEDLINE and the Cochrane Central Library from inception to June 2015 to identify relevant studies. There were no language restrictions. We also searched reference lists from potentially relevant papers and review articles, as well as proceedings from annual meetings (1991-2015) of the American Gastroenterological Association and American College of Gastroenterology.

SELECTION CRITERIA

Randomized controlled trials that evaluated the efficacy of sulfasalazine or mesalamine in the treatment of mildly to moderately active Crohn's disease compared to placebo, corticosteroids, and other aminosalicylates (alone or in combination with corticosteroids) were included.

DATA COLLECTION AND ANALYSIS

Data extraction and assessment of methodological quality was independently performed by the investigators and any disagreement was resolved by discussion and consensus. We assessed methodological quality using the Cochrane risk of bias tool. The overall quality of the evidence supporting the outcomes was evaluated using the GRADE criteria. The primary outcome measure was a well defined clinical endpoint of induction of remission or response to treatment. Secondary outcomes included mean Crohn's disease activity index (CDAI) scores, adverse events, serious adverse events and withdrawal due to adverse events. For dichotomous outcomes we calculated the pooled risk ratio (RR) and corresponding 95% confidence interval (CI) using a random-effects model. For continuous outcomes we calculated the mean difference (MD) and 95% CI using a random-effects model. Sensitivity analyses based on a fixed-effect model and duration of therapy were conducted where appropriate.

MAIN RESULTS

Twenty studies (2367 patients) were included. Two studies were judged to be at high risk of bias due to lack of blinding. Eight studies were judged to be at high risk of bias due to incomplete outcomes data (high drop-out rates) and potential selective reporting. The other 10 studies were judged to be at low risk of bias. A non-significant trend in favour of sulfasalazine over placebo for inducing remission was observed, with benefit confined mainly to patients with Crohn's colitis. Forty-five per cent (63/141) of sulfasalazine patients entered remission at 17-18 weeks compared to 29% (43/148) of placebo patients (RR 1.38, 95% CI 1.00 to 1.89, 2 studies). A GRADE analysis rated the overall quality of the evidence supporting this outcome as moderate due to sparse data (106 events). There was no difference between sulfasalazine and placebo in adverse event outcomes. Sulfasalazine was significantly less effective than corticosteroids and inferior to combination therapy with corticosteroids (RR 0.64, 95% CI 0.47 to 0.86, 1 study, 110 patients). Forty-three per cent (55/128) of sulfasalazine patients entered remission at 17 to 18 weeks compared to 60% (79/132) of corticosteroid patients (RR 0.68, 95% CI 0.51 to 0.91; 2 studies, 260 patients). A GRADE analysis rated the overall quality of the evidence supporting this outcome as moderate due to sparse data (134 events). Sulfasalazine patients experienced significantly fewer adverse events than corticosteroid patients (RR 0.43, 95% CI 0.22 to 0.82; 1 study, 159 patients). There was no difference between sulfasalazine and corticosteroids in serious adverse events or withdrawal due to adverse events. Olsalazine was less effective than placebo in a single trial (RR 0.36, 95% CI 0.18 to 0.71; 91 patients). Low dose mesalamine (1 to 2 g/day) was not superior to placebo for induction of remission. Twenty-three per cent (43/185) of low dose mesalamine patients entered remission at week 6 compared to 15% (18/117) of placebo patients (RR = 1.46, 95% CI 0.89 to 2.40; n = 302). A GRADE analysis indicated that the overall quality of the evidence supporting this outcome was low due to risk of bias (incomplete outcome data) and sparse data (61 events). There was no difference between low dose mesalamine and placebo in the proportion of patients who had adverse events (RR 1.33, 95% CI 0.91 to 1.96; 3 studies, 342 patients) or withdrew due to adverse events (RR 1.21, 95% CI 0.75 to 1.95; 3 studies, 342 patients). High dose controlled-release mesalamine (4 g/day) was not superior to placebo, inducing a clinically non significant reduction in CDAI (MD -19.8 points, 95% CI -46.2 to 6.7; 3 studies, 615 patients), and was also inferior to budesonide (RR 0.56, 95% CI 0.40 to 0.78; 1 study, 182 patients, GRADE = low). While high dose delayed-release mesalamine (3 to 4.5 g/day) was not superior to placebo for induction of remission (RR 2.02, 95% CI 0.75 to 5.45; 1 study, 38 patients, GRADE = very low), no significant difference in efficacy was found when compared to conventional corticosteroids (RR 1.04, 95% CI 0.79 to 1.36; 3 studies, 178 patients, GRADE = moderate) or budesonide (RR 0.89, 95% CI 0.76 to 1.05; 1 study, 307 patients, GRADE = moderate). However, these trials were limited by risk of bias (incomplete outcome data) and sparse data (small numbers of events). There was a lack of good quality clinical trials comparing sulfasalazine with other mesalamine formulations. Adverse events that were commonly reported included headache, nausea, vomiting, abdominal pain and diarrhea.

AUTHORS' CONCLUSIONS

Sulfasalazine is only modestly effective with a trend towards benefit over placebo and is inferior to corticosteroids for the treatment of mildly to moderately active Crohn's disease. Olsalazine and low dose mesalamine (1 to 2 g/day) are not superior to placebo. High dose mesalamine (3.2 to 4 g/day) is not more effective than placebo for inducing response or remission. However, trials assessing the efficacy of high dose mesalamine (4 to 4.5 g/day) compared to budesonide yielded conflicting results and firm conclusions cannot be made. Future large randomized controlled trials are needed to provide definitive evidence on the efficacy of aminosalicylates in active Crohn's disease.

Synthesis, colon-targeted studies and pharmacological evaluation of an anti-ulcerative colitis drug 4-Aminosalicylic acid-β-O-glucoside

A glycoside prodrug of 4-aminosalicylic acid (4-ASA) with d-glucose was synthesized for targeted drug delivery to inflammatory bowel. The in vitro assessment of 4-aminosalicylic acid-β-O-glucoside (4-ASA-Glu) as a colon-specific prodrug was studied using colitis rat with the healthy one as control. The stability studies in aqueous buffers (pH 1.2, 6.8 and 7.4) indicated that 4-ASA-Glu was stable over a period of 12 h. The incubation of 4-ASA-Glu with cecal or colonic contents of healthy rats at 37 °C released 4-ASA in 77 or 80% of the dose in 12 h, respectively. The amount of 4-ASA liberated from the incubation of 4-ASA-Glu in cecal or colonic contents of colitis rats at 37 °C was 69 or 79% in 12 h respectively, while less than 9% 4-ASA was detected from the incubation of 4-ASA-Glu with the homogenates of stomach or small intestine. The curative effect of 4-ASA-Glu was evaluated in 2, 4, 6-trinitrobenzenesulfonic acid (TNBS) induced experimental colitis model in male Sprague-Dawley (SD) rats. It was found that 4-ASA-Glu possess significantly ameliorate effect than sulfasalazine, oral 4- and 5-aminosalicylic acid.

Dextran Carrier Macromolecules for Colon-specific Delivery of 5-Aminosalicylic Acid

Present manuscript describes the sustained and targeted delivery of 5-aminosalicylic acid to the distal ileum and proximal colon, using dextran (40 kDa) as a carrier for targeting 5-aminosalicylic acid at the colonic site by attaching p-aminobenzoic acid and benzoic acid as linkers. Prepared conjugate were characterized by UV, HPLC, FT-IR, and ¹H NMR. The degree of substitution was estimated by complete hydrolysis of conjugates in borate buffer and in vitro hydrolysis study of conjugates was performed in different biological media. It was observed that 5-aminosalicylic acid alone have produced high incidence of gastric ulcer with high ulcer index whereas lower ulcer index was found for the dextran conjugates of 5-aminosalicylic acid. The release pattern of conjugates in 3% w/v rat caecal content was confirmed the colon specificity of 5-aminosalicylic acid conjugates.

Synthesis and evaluation of mutual azo prodrug of 5-aminosalicylic acid linked to 2-phenylbenzoxazole-2-yl-5-acetic acid in ulcerative colitis

In this study, the syntheses of 4-aminophenylbenzoxazol-2-yl-5-acetic acid, (an analogue of a known nonsteroidal anti-inflammatory drug [NSAID]) and 5-[4-(benzoxazol-2-yl-5-acetic acid)phenylazo]-2-hydroxybenzoic acid (a novel mutual azo prodrug of 5-aminosalicylic acid [5-ASA]) are reported. The structures of the synthesized compounds were confirmed using infrared (IR), hydrogen-1 nuclear magnetic resonance (1H NMR), and mass spectrometry (MS) spectroscopy. Incubation of the azo compound with rat cecal contents demonstrated the susceptibility of the prepared azo prodrug to bacterial azoreductase enzyme. The azo compound and the 4-aminophenylbenzoxazol-2-yl-5-acetic acid were evaluated for inflammatory bowel diseases, in trinitrobenzenesulfonic acid (TNB)-induced colitis in rats. The synthesized diazo compound and the 4-aminophenylbenzoxazol-2-yl-5-acetic acid were found to be as effective as 5-aminosalicylic acid for ulcerative colitis. The results of this work suggest that the 4-aminophenylbenzoxazol-2-yl-5-acetic acid may represent a new lead for treatment of ulcerative colitis.

[Guidelines for the management of Crohn's disease]

Crohn's disease (CD) is a chronic inflammatory bowel disease (IBD) with uncertain etiopathogenesis. CD can involve any site of gastrointestinal tract from the mouth to anus and is associated with serious complications such as bowel strictures, perforations, and fistula formation. The incidence and prevalence rates of CD in Korea are still lower than those of Western countries, but have been rapidly increasing during the past decades. Although there are no definitive curative modalities for CD, various medical and surgical therapies are currently applied for diverse clinical situations of CD. However, a lot of decisions on the management of CD are made depending on the personal experiences and choices of physicians. To suggest preferable approaches to diverse problems of CD and to minimize the variations according to physicians, guidelines for the management of CD are needed. Therefore, IBD Study Group of the Korean Association for the Study of the Intestinal Diseases has set out to develop the guidelines for the management of CD in Korea. These guidelines were developed using the adaptation methods and encompass the treatment of inflammatory disease, stricturing disease, and penetrating disease. The guidelines also cover the indication of surgery, prevention of recurrence after surgery, and CD in pregnancy and lactation. These are the first Korean guidelines for the management of CD and the update with further scientific data and evidences is needed.

Medical management of Crohn's disease

INTRODUCTION

The medical approach to Crohn's disease has been modified in recent years thanks to the introduction of new therapies, like biologics. Also, well-designed studies and systematic reviews have allowed better evaluation of the role of old drugs like steroids and immunosuppressors. This review aims to evaluate the recent evidence on the medical approach to Crohn's disease in the different settings of the disease.

AREAS COVERED

Randomized controlled trials and meta-analyses were included in the review. The research on all the studies discussed was based on the Cochrane Library, Medline and Embase, using the following medical subject headings: Crohn's disease, clinical trial, therapy, 5-aminosalicylic acid, steroid, budesonide, immunosuppressant, anti-meta-analysis TNF and biologics.

EXPERT OPINION

In a mild active inflammatory ileocecal disease, budesonide is considered the best approach. The efficacy of aminosalicylates is limited, but a trial that has recently compared aminosalicylates and budesonide has shown that the two drugs are comparable. In a mild colonic disease, sulfasalazine, antibiotics and steroids are effective but the evidence for antibiotics is less clear. The maintenance of remission in this setting is debatable, but sulfasalazine seems the better choice. In a moderate severe ileal and colonic disease, steroids are the best therapy to induce remission. Once remission is reached, immunosuppressors remain today the better choice to maintain the remission. Anti-TNF therapy is indicated in patients intolerant or not responding to steroids and immunosuppressors and in fistulizing Crohn's disease. Early therapy with biologics may be considered in patients with severe disease.

Update on the management of Crohn's disease

Crohn's disease (CD) is a chronic inflammatory disorder characterized by focal, asymmetric, transmural inflammation of any part of the luminal gastrointestinal tract of uncertain etiology and an unpredictable course. The available treatment options include aminosalicylates, budesonide and systemic corticosteroids, antibiotics, immunomodulators,methotrexate and anti-TNF agents. This review discusses recent developments in the treatment of CD and provides a comprehensive update on management of patients with CD based on the data from randomized controlled trials.

Inflammatory bowel disease therapy: current state-of-the-art

PURPOSE OF REVIEW

The aim of this article is to review current evidence-based approaches to treatment of ulcerative colitis and Crohn's disease.

RECENT FINDINGS

The primary goal of treatment is to induce and to maintain remission in a safe and efficacious fashion. The 5-aminosalicylic acid (5-ASA) agents and oral steroids remain the first-line approach for the treatment of ulcerative colitis and Crohn's disease. The 'step-up' approach includes the use of immunomodulators [azathioprine (AZA), or 6-mercaptopurine (6-MP)] and newer biologic agents (infliximab, adalimumab, and natalizumab). The 'step-down' approach can also be considered individually on the basis of the severity of Crohn's disease.

SUMMARY

Current treatment regimens still involve medications with well known efficacy and safety profiles and progress to more potent treatments such as immunomodulators and biologic agents. Adverse events of potent treatment with biologics and immunomodulators have been recognized. In some cases, aggressive approaches with the use of more potent agents as first-line therapy has been proposed, but they are still not considered a routine approach.

Searching for the delta: 5-aminosalicylic Acid therapy for Crohn's disease

Crohn's disease (CD) is a chronic inflammatory condition that often requires lifelong medical therapy for the induction and maintenance of remission. Oral mesalamine (5-aminosalicylic acid [5-ASA]) therapy has several forms, which can be categorized into oral formulations and prodrugs. The ability to demonstrate the efficacy of 5-ASA is limited in most clinical trials by the nonspecific endpoints of the Crohn's Disease Activity Index. Overall, clinical trials have not shown 5-ASA therapy to be superior to placebo for the induction of remission, with the exception of sulfasalazine in colonic CD. 5-ASA therapy has also not been shown to be superior to placebo for maintenance of medically induced remission; however, mesalamine may have a modest effect in surgically induced remission. Further research is needed regarding the optimal monitoring and therapy for patients with mild CD who often achieve remission with placebo in clinical trials.

Crohn's disease

INTRODUCTION

Crohn's disease is a chronic condition of the gastrointestinal tract. It is characterised by transmural, granulomatous inflammation that occurs in a discontinuous pattern, with a tendency to form fistulae. The cause is unknown but may depend on interactions between genetic predisposition, environmental triggers, and mucosal immunity.

METHODS AND OUTCOMES

We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of medical treatments to induce remission in adults with Crohn's disease? What are the effects of surgical interventions to induce and maintain remission in adults with small-bowel Crohn's disease? What are the effects of surgical interventions to induce remission in adults with colonic Crohn's disease? What are the effects of medical interventions to maintain remission in adults with Crohn's disease; and to maintain remission following surgery? What are the effects of lifestyle interventions to maintain remission in adults with Crohn's disease? We searched: Medline, Embase, The Cochrane Library, and other important databases up to December 2009 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).

RESULTS

We found 93 systematic reviews, RCTs, or observational studies that met our inclusion criteria.

CONCLUSIONS

In this systematic review we present information relating to the effectiveness and safety of the following interventions: aminosalicylates, antibiotics, azathioprine/mercaptopurine, ciclosporin, corticosteroids (oral), enteral nutrition, fish oil, infliximab, methotrexate, probiotics, resection, segmental colectomy, smoking cessation, and strictureplasty.

Efficacy of 5-aminosalicylates in Crohn's disease: systematic review and meta-analysis

OBJECTIVES

Crohn's disease (CD) is a chronic inflammatory disorder of the gastrointestinal tract. Evidence for treatment with 5-aminosalicylic acid (5-ASA) drugs is conflicting. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to examine this issue.

METHODS

MEDLINE, EMBASE, and the Cochrane central register of controlled trials were searched (through December 2010). Authors of studies were contacted to provide additional information on trials where required, and experts in the field were contacted to identify unpublished studies. Eligible trials recruited adults with active or quiescent CD and compared 5-ASAs with placebo, or no treatment. Dichotomous data were pooled to obtain relative risk (RR) of failure to achieve remission in active CD, and RR of relapse of disease activity in quiescent CD, with a 95% confidence interval (CI). The number needed to treat (NNT) was calculated from the reciprocal of the risk difference.

RESULTS

The search identified 3,061 citations. Twenty-two RCTs were eligible. Six RCTs compared 5-ASA with placebo in active CD remission. There was a trend towards a benefit with sulfasalazine over placebo (two RCTs, RR of failure to achieve remission=0.83; 95% CI=0.69-1.00), but no definite benefit of mesalamine over placebo (four RCTs, RR=0.91; 95% CI=0.77-1.06). Neither sulfasalazine nor mesalamine were effective in preventing quiescent CD relapse, but in a per protocol analysis mesalamine appeared to reduce risk of relapse (RR=0.79; 95% CI=0.66-0.95, NNT=13).

CONCLUSIONS

The role of 5-ASAs in inducing remission of active CD and preventing relapse of quiescent CD remains uncertain, and more RCTs are required.

Aminosalicylates for induction of remission or response in Crohn's disease

BACKGROUND

Controlled clinical trials investigating the efficacy of aminosalicylates for the treatment of mildly to moderately active Crohn's disease have yielded conflicting results. A systematic review was conducted to critically examine current available data on the efficacy of sulfasalazine and mesalamine for inducing remission or clinical response in patients with mildly to moderately active Crohn's disease.

OBJECTIVES

To evaluate the efficacy of aminosalicylates compared to placebo, corticosteroids, and other aminosalicylates (alone or in combination with corticosteroids) for the treatment of mildly to moderately active Crohn's disease.

SEARCH STRATEGY

Separate MEDLINE (1966-July 2010), Cochrane Central Register of Controlled Trials (CENTRAL; Issue 3, 2010) and EMBASE database searches (1985-July 2010) of all relevant English and non-English language articles were performed, followed by manual searches of the reference list from potentially relevant papers and review articles, as well as proceedings from annual meetings (1991-2010) of the American Gastroenterological Association (AGA) and American College of Gastroenterology (ACG).

SELECTION CRITERIA

Randomized controlled trials that evaluated the efficacy of sulfasalazine or mesalamine in the treatment of mildly to moderately active Crohn's disease compared to placebo, corticosteroids, and other aminosalicylates (alone or in combination with corticosteroids) were included.

DATA COLLECTION AND ANALYSIS

Data extraction and assessment of methodological quality of each selected study was independently performed by the investigators and any disagreement was resolved by discussion and consensus. The primary outcome measure was a well defined clinical endpoint of induction of remission or response to treatment. Nineteen studies met the inclusion criteria and were analyzed. Pooled relative risks (RR) for inducing remission or clinical response and their 95% confidence intervals were calculated (random effects model) where appropriate.

MAIN RESULTS

Sulfasalazine was more likely to induce remission (RR 1.38; 95% CI 1.02 to 1.87; n = 263) compared to placebo with benefit confined mainly to patients with colitis. Sulfasalazine was less effective than corticosteroids (RR 0.66; 95% CI 0.53 to 0.81; n = 260). Olsalazine was less effective than placebo in a single trial. Low dose mesalamine (1 to 2 g/day) was not superior to placebo (RR = 1.46, 95% CI 0.89-2.40; n = 302) and was less effective than corticosteroids. High dose mesalamine (3 to 4.5 g/day) was not superior to placebo for induction of remission (RR 2.02; 95% CI 0.75 to 5.45) or response (Weighted Mean Difference -19.8 points; 95% CI -46.2 to 6.7; n = 615). In a single randomized controlled trial, 5-ASA was inferior to budesonide (RR 0.56; 95% CI 0.40 to 0.78). No statistically significant difference was found between high dose mesalamine and conventional corticosteroids (RR 1.04; 95% CI 0.79 to 1.36; n = 178). However, relatively few patients were available for analysis. There was a lack of good quality clinical trials comparing sulfasalazine with other mesalamine formulations.

AUTHORS' CONCLUSIONS

Sulfasalazine has modest efficacy compared to placebo and is inferior to corticosteroids for the treatment of mild to moderately active Crohn's disease. Olsalazine and low dose mesalamine (1 to 2 g/day) are not superior to placebo. High dose mesalamine (3 to 4.5 g/day) is not more effective than placebo for inducing response or remission. High dose mesalamine was inferior to budesonide for inducing remission in a single trial. In conclusion, sulfasalazine shows modest efficacy for the treatment of active Crohn's disease. However, the existing data show little benefit for 5-aminosalicylates.

What is the optimal therapy for Crohn's disease: step-up or top-down?

Crohn's disease (CD) is an idiopathic chronic inflammatory disorder of the digestive tract, which is incurable. Present therapeutic guidelines follow a sequential step-up approach that focuses on treating acute disease or 'inducing clinical remission' and subsequently aims to 'maintain clinical response'. In view of the chronic relapsing-remitting disabling disease course, new treatment approaches have been sought with the ultimate end point of disease course modification and mucosal healing. A recent preliminary study from D'Haens et al. has provided evidence suggesting that reversing the treatment paradigm from a 'step-up' to a 'top-down' approach may positively alter the natural course of this illness. Their findings indicate that early use of biologic therapy, in combination with immunomodulators, resulted in remission occuring more rapidly than the conventional 'step-up' treatment, with a longer time period to relapse, a decreased need for treatment with corticosteroids, a faster reduction in clinical symptoms, rapid decline in biochemical inflammatory markers (C-reactive protein) and improved endoscopic mucosal healing. These results, supported by previous studies on infliximab use, may hold a promising outcome of fewer stricturing complications, hospitalizations and surgeries for patients with CD. However, we need to better define the timing and candidates for the 'top-down' approach as we are still uncertain about the safety data and the long-term benefits if biologic agents are given as routine maintenance treatment, since most of the trials in CD have been short term, and approximately 30% of patients might have been overtreated. Future clinical trials will be crucial in answering these questions.

Interventions for prevention of post-operative recurrence of Crohn's disease

BACKGROUND

Recurrence of Crohn's disease is common after intestinal resection. A number of agents have been studied in controlled trials with the goal of reducing the risk of endoscopic or clinical recurrence of Crohn's disease following surgery.

OBJECTIVES

To undertake a systematic review of the use of medical therapies for the prevention of post-operative recurrence of Crohn's disease

SEARCH STRATEGY

MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched to identify relevant studies. References from selected papers and abstracts from Digestive Disease Week were also searched.

SELECTION CRITERIA

Randomised controlled trials that compared medical therapy to placebo or other medical agents for the prevention of recurrence of intestinal Crohn's disease were selected for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors reviewed all abstracts containing search terms, and those meeting inclusion criteria were selected for full data abstraction. Dichotomous data were summarised using relative risk and 95% confidence intervals. A fixed-effects model was used, and sensitivity analysis performed.

MAIN RESULTS

Twenty-three studies were identified for inclusion. Probiotics were not superior to placebo for any outcome measured. The use of nitroimidazole antibiotics appeared to reduce the risk of clinical (RR 0.23; 95%CI 0.09 to 0.57, NNT=4) and endoscopic (RR 0.44; 95%CI 0.26 to 0.74, NNT = 4) recurrence relative to placebo. However, these agents were associated with higher risk of serious adverse events (RR 2.39, 95% CI 1.5 to 3.7). Mesalamine therapy was associated with a significantly reduced risk of clinical recurrence (RR 0.76; 95% CI 0.62 to 0.94, NNT = 12), and severe endoscopic recurrence (RR 0.50; 95% CI 0.29 to 0.84, NNT = 8) when compared to placebo. Azathioprine/6MP was also associated with a significantly reduced risk of clinical recurrence (RR 0.59; 95% CI 0.38 to 0.92, NNT = 7), and severe endoscopic recurrence (RR 0.64; 95% CI 0.44 to 0.92, NNT = 4), when compared to placebo. Neither agent had a higher risk than placebo of serious adverse events. When compared to azathioprine/6MP, mesalamine was associated with a higher risk of any endoscopic recurrence (RR 1.45, 95% CI 1.03 to 2.06), but a lower risk of serious adverse events (RR 0.51; 95% CI 0.30 to 0.89). There was no significant difference between mesalamine and azathioprine/6MP for any other outcome.

AUTHORS' CONCLUSIONS

There are insufficient randomised controlled trials of infliximab, budesonide, tenovil and interleukin-10 to draw conclusions. Nitro-imidazole antibiotics, mesalamine and immunosuppressive therapy with azathioprine/6-MP or infliximab all appear to be superior to placebo for the prevention of post-operative recurrence of Crohn's disease. The cost, toxicity and tolerability of these approaches require careful consideration to determine the optimal approach for post-operative prophylaxis.

Medical management of mild to moderate Crohn's disease: evidence-based treatment algorithms for induction and maintenance of remission

BACKGROUND

Patients with Crohn's disease alternate between periods of active, symptomatic disease and periods of remission. The treatment goal for Crohn's disease is to induce and then maintain remission of symptoms.

AIM

To review evidence from randomized, controlled, clinical trials on medical therapies for inducing and maintaining remission in patients with mild-to-moderate Crohn's disease, and to suggest the best evidence-based approaches for induction and maintenance therapies.

METHODS

PubMed search using the following terms: sulfasalazine or salicylazosulfapyridine or aminosalicylate or aminosalicylic acid or mesalamine or mesalazine or corticosteroid or prednisone or prednisolone or methylprednisolone or budesonide or antibiotic or metronidazole or ciprofloxacin or immunosuppressive or azathioprine or mercaptopurine or thiopurine or methotrexate and Crohn's disease.

RESULTS

Randomized, controlled trials demonstrated that sulfasalazine, budesonide, and conventional corticosteroids are effective for inducing remission of mild-to-moderate Crohn's disease when administered for a period of 8-16 weeks. An ideal maintenance therapy does not currently exist.

CONCLUSIONS

Selection of maintenance therapy is based on a combination of evidence from controlled trials and patient features including disease severity and location, co-morbidities, previous response to treatment, and previous surgical resection. The options for maintenance therapy include therapy cessation and patient observation following successful induction, budesonide, or immunosuppressive therapy.

Systematic review: the potential influence of mesalazine formulation on maintenance of remission in Crohn's disease

AIM

To evaluate the effectiveness of pH 6-/pH 7-dependent and controlled-release mesalazines in maintaining medically and surgically induced Crohn's disease remission.

METHODS

A systematic search identified 13 randomized controlled trials (RCTs). The rate of symptomatic relapse (Crohn's disease activity index >150, or an increase in baseline by at least 60-100 points) was extracted from each randomized controlled trial. Pooled odds ratios (OR), the number needed to treat (NNT), and percentage therapeutic benefit (absolute risk reduction) were calculated.

RESULTS

Treatment with pH 7-dependent mesalazine significantly reduced the risk of relapse in patients with either surgically [OR 0.28; 95% confidence interval (CI) 0.12-0.65; P = 0.0032] or medically induced remission (OR 0.38; 95% CI 0.17-0.85; P = 0.0113). However, treatment with controlled-release mesalazine and pH 6-dependent mesalazine failed to show any significant advantage over placebo. The NNT to maintain surgically or medically induced remission was lowest for pH 7-dependent mesalazine (NNT = 4 and 5, respectively; NNT = 15 and 16 for controlled-release mesalazine and NNT = 11 and 23 for pH 6-dependent mesalazine). Therapeutic benefit was highest for pH 7-dependent mesalazine (surgical = 30.6%, medical = 22.8%). This compared with 6.9% (surgical) and 6.4% (medical) for controlled-release mesalazine, and 9.8% and 4.4%, respectively, for pH 6-dependent mesalazine.

CONCLUSION

Further trials of pH 7-dependent mesalazine formulations are warranted in the maintenance of remission in Crohn's disease.

Indications for 5-aminosalicylate in inflammatory bowel disease: is the body of evidence complete?

Mesalazine is a safe drug, although adverse events may be seen in a minority of patients. This applies also to pregnant women and children. The role of mesalazine in combination therapy to improve efficacy and concomitant drug pharmacokinetics, or in chemoprevention against inflammatory bowel disease (IBD)-related colonic carcinoma has not yet been completely elucidated. Therapeutic success of mesalazine may be optimized by a combination of high dose and low frequency of dosage to improve compliance. Therefore, due to its superior safety profile and pharmacokinetic characteristics, mesalazine is preferable to sulphasalazine. This paper reviews the literature concerning mechanisms of action, indications and off-label use, pharmacokinetic properties and formulations, therapeutic efficacy, compliance, paediatric indications, chemoprevention, and safety issues and adverse event profile of mesalazine treatment versus sulphasalazine. It also highlights these controversies in order to clarify the potential benefits of mesalazines in IBD therapy and evidence for its use.

European evidence based consensus on the diagnosis and management of Crohn's disease: current management

This second section of the European Crohn's and Colitis Organisation (ECCO) Consensus on the management of Crohn's disease concerns treatment of active disease, maintenance of medically induced remission, and surgery. The first section on definitions and diagnosis includes the aims and methods of the consensus, as well as sections on diagnosis, pathology, and classification of Crohn's disease. The third section on special situations in Crohn's disease includes postoperative recurrence, fistulating disease, paediatrics, pregnancy, psychosomatics, extraintestinal manifestations, and alternative therapy for Crohn's disease.

Comparative analysis of the in vitro prosecretory effects of balsalazide, sulfasalazine, olsalazine, and mesalamine in rabbit distal ileum

BACKGROUND

The aminosalicylates remain foundation therapy for mild-to-moderate ulcerative colitis. Pro-drug 5-aminosalicylic acid (5-ASA; mesalamine) formulations have been developed to prevent 5-ASA from the proximal absorption and release of mesalamine, to decrease inflammation, and to improve colonic absorption. Clinically, pro-drugs such as olsalazine have been associated with dose-dependent diarrhea, which was likely secondary to ileal secretion induced by the azo linkages, in 17% of patients. The present study tested the hypothesis that the use of all compounds with azo linkages leads to increased secretion.

METHODS

Intestinal tissue was randomly assigned to serve as controls or to receive brush border addition of equimolar concentrations of the compounds, and the change in short-circuit current was measured.

RESULTS

Mesalamine did not induce secretion at any dose. Mean equivalent doses (0.1 to 10 mM) of balsalazide (range, 6.3 +/- 1.5 to 16.7 +/- 1.3 microA/cm2), olsalazine (range, 2.0 +/- 1.0 to 7.0 +/- 2.1 microA/cm2), and sulfasalazine (3.2 +/- 1.1 to 6.2 +/- 1.5 microA/cm2) significantly stimulated (P < 0.001) secretion. The values for the effective dose that is half the maximal dose for secretion induced by sulfasalazine, olsalazine, and balsalazide were 0.4, 0.7, and 0.9 mM, respectively.

CONCLUSIONS

This study is the first to demonstrate that the use of pro-drugs with azo bonds leads to increased ileal secretion at equimolar concentrations of 5-ASA. Physicians should use caution when providing higher doses of the pro-drug forms of 5-ASA to their patients, as this could lead to increased diarrhea.

Oral 5-aminosalicylic acid for maintenance of medically-induced remission in Crohn's Disease

BACKGROUND

Prevention of relapses is a major issue in the management of Crohn's disease. Corticosteroids, the mainstay of treatment of acute exacerbations are not effective in the maintenance of remission and its chronic use is limited by numerous adverse events. A number of randomised controlled trials comparing various 5-ASA agents with either placebo or other drugs have had conflicting results.

OBJECTIVES

To conduct a systematic review to evaluate the efficacy of oral 5-ASA agents for the maintenance of medically-induced remission in Crohn's disease.

SEARCH STRATEGY

We searched MEDLINE (1966 to January 2004), EMBASE (1984-January 2004), the Cochrane Central Register of Controlled Trials from the Cochrane Library (Issue 1, 2004) and the IBD Review Group Specialized Trials Register. We hand-searched the articles cited in each publication.

SELECTION CRITERIA

We included randomised controlled trials which compared oral 5-ASA agents with either placebo or sulphasalazine, with treatment durations of at least 6 months.

DATA COLLECTION AND ANALYSIS

Data extraction and assessment of methodological quality of each study were independently performed by two reviewers. Any disagreement among reviewers was resolved by consensus. The main outcome measure was the occurrence of relapse as defined by the primary studies. Odds ratios of relapse rates and their 95% confidence intervals were calculated.

MAIN RESULTS

5-ASA VERSUS PLACEBO. In the main analysis, we used as the denominator the total number of patients randomised. We assumed that participants who dropped out of the study, and on whom there was no post withdrawal information, had relapsed during the study period. Using the fixed effects model, the odds ratio for 6 studies where participants were followed up for 12 months was 1.00 (95%CI, 0.80 to 1.24). Using the random effects model in a sensitivity analysis had little effect on the results with an OR of 0.93 (95% CI, 0.65 to 1.33). For the seventh study where follow up was for 24 months, the odds ratio was 0.98; 95% CI, 0.51 to 1.90. In further sensitivity analyses, we analysed only participants who completed the study and ignored the dropouts. The odds ratio (fixed effects model) for the 6 studies where follow up was for 12 months was 0.74 (95% CI, 0.57 to 0.96), but using the random effects model, the OR was 0.68 (95% CI 0.45 to 1.02). The OR for the seventh study where follow up was for 24 months (Gendre 1993a), was 0.86; 95% CI, 0.42 to 1.78. 5-ASA VERSUS SULPHASALAZINE. We did not find any study that satisfied the inclusion criteria.

AUTHORS' CONCLUSIONS

We found no evidence in this review to suggest that 5-ASA preparations are superior to placebo for the maintenance of medically-induced remission in patients with Crohn's disease. Therefore it appears that additional randomised trials of this regime are not justified.

Mesalamine delivery systems: do they really make much difference?

Sulfasalazine's role as the first-line of therapy in patients with inflammatory bowel disease has led to the development of other "designer" aminosalicylates, which eliminate the sulfa-moiety, and attempt to target the topically active mesalamine to the inflamed bowel. Olsalazine sodium and balsalazide disodium utilize the same azo-bond structure as sulfasalazine, requiring release of active mesalamine by colonic bacteria, and thus targeting these agents to the colon. Other mesalamine delivery systems use pH-dependant- or moisture-release to liberate the active mesalamine in both the large and small bowel. Direct application of mesalamine via enema or suppository is also effective in patients with distal colitis. The pharmacology and thus the undesirable drug absorption rates differ between drugs, although the clinical importance of these characteristics is debatable. Differences in release-systems, the impact of the fed and fasting state, and unique patient intolerances to individual agents demand an understanding of each of these products, and their application to patient therapy.

Advances in the treatment of Crohn's disease

The medical therapy of Crohn's disease has improved considerably in recent years. In large part, this is due to the introduction of new efficacious agents, both "biologics" and traditional small molecules. Further study of older drugs has also advanced our ability to devise the optimum approach to individual Crohn's disease patients by better clarifying the benefits, adverse effects, and means to optimize doses of established medications. In this review, we present an evidence-based approach to the medical management of active Crohn's disease, Crohn's disease in remission, and perianal Crohn's disease that emphasizes recent advances that have come from the results of randomized controlled clinical trials.

Scientific Surgery

The BJS is committed to the practice of surgery based on scientific evidence. Each month we will publish a list of randomized trials and meta-analyses collated from English-language publications. A collection of all these papers will be available in the Scientific Surgery archive which will be held on the BJS website together with links to free Medline sites where the full papers can be accessed (see below for details). If you have recently published a randomized trial that has not been featured in Scientific Surgery, the Editors would be pleased to receive a reprint and consider its inclusion.

Therapy of Crohn's disease in childhood

Crohn's disease in childhood is a chronic relapsing and remitting condition that can significantly impact on normal growth and development. This influences the choice of both initial and ongoing management. The goal of therapy is to induce and maintain remission with minimal side effects. Enteral nutrition as the sole therapy for active disease is effective in some children, thus avoiding the use of corticosteroids. In disease that is resistant to conventional treatment, immunosuppression or anti-tumour necrosis factor therapy is indicated. We review the use of these treatments and discuss the new therapies being developed, including antibodies, cytokines and probiotics.