NEW YORK (Reuters Health) – After surgically induced remission of Crohn’s disease, treatment with mesalamine reduces the risk of relapse somewhat; sulfasalazine, however, has no apparent benefit, according the results of a meta-analysis.

Reporting in the American Journal of Gastroenterology published online August 17, Dr. Alexander C. Ford with Leeds General Infirmary, UK, and colleagues note that there’s conflicting evidence about the value of 5-aminosalicyclic acid (5-ASA) drugs for patients with Crohn’s disease in remission after surgical resection.

To clarify the issue, the researchers conducted a systematic review of the medical literature for relevant randomized clinical trials and identified 11 that were eligible for a meta-analysis. The trials included 1282 patients and compared mesalamine or sulfasalazine to placebo or no treatment.

“Therapy with 5-ASAs significantly reduced the likelihood of relapse of disease activity (RR = 0.86),” the investigators found.

However, on further analysis, the relative risk reduction for relapse with sulfasalazine was not significant (RR = 0.97) while mesalamine significantly reduced the likelihood of relapse to a modest extent (RR = 0.80).

Should mesalamine be routinely used in this setting? “There is only a modest benefit, but mesalamine is a safe enough drug, and patients with Crohn’s are often left on no treatment after a first surgical resection,” Dr. Ford commented via email, “so I guess the data tell us that giving mesalamine routinely in this situation is better than doing nothing (given that these are nearly all placebo-controlled trials).”

Asked why there’s a difference in therapeutic efficacy between sulfasalazine and its derivative mesalamine, Dr. Ford said the reasons are speculative.

“There may have been a lack of power of the meta-analysis to detect a significant difference between sulfasalazine and placebo in preventing relapse of disease activity due to fewer trials containing a smaller number of participants leading to a type II error, or a genuine lack of therapeutic efficacy due to the differences between these drugs at the molecular level,” he noted. “Certainly doses of sulfasalazine and mesalamine were comparable across all trials, so this is unlikely to have exerted any great effect on the results we observed.”

Overall, the authors conclude that mesalamine use to prevent relapse of Crohn’s disease in remission after surgery should be considered for patients who are not candidates for immunosuppression. Future trials, they add, “should try to identify subgroups of patients who derive the most benefit from this approach.”

Reference:

5-Aminosalicylates Prevent Relapse of Crohn’s Disease After Surgically Induced Remission: Systematic Review and Meta-Analysis

Am J Gastroenterol 2010.