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

Akobeng AK, Gardener E

Published Online:

October 7, 2009

Prevention of relapse is a key objective in the management of Crohn's disease. There is no current treatment available that completely maintains remission and is without significant side-effects. 5-ASA (aminosalicylic acid) preparations are frequently used to maintain remission. This review found no evidence to suggest that 5-ASA preparations are superior to placebo (no treatment) in maintaining medically-induced remission. A meta-analysis was not performed on the occurrence of adverse events because of the different reporting methods used by trials, but incidence of adverse events did not appear to be different between patients receiving 5-ASA preparations compared with those receiving placebo. In conclusion, there is no evidence that 5-ASA preparations are superior to placebo for the maintenance of medically-induced remission in patients with Crohn's disease.

Abstract (click to read)

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.

This record should be cited as:

Akobeng AK, Gardener E. Oral 5-aminosalicylic acid for maintenance of medically-induced remission in Crohn's disease. Cochrane Database of Systematic Reviews 2005, Issue 1. Art. No.: CD003715. DOI: 10.1002/14651858.CD003715.pub2

Assessed as up to date:

November 10, 2004

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Primary Review Group:

Inflammatory Bowel Disease and Functional Bowel Disorders Group

Health topics:

Gastroenterology > Inflammatory bowel disease > Crohn's disease: maintenance of remission

Cochrane Summaries^beta

Independent high-quality evidence for health care decision making

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

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