Once Versus Twice Daily Mesalamine to Induce Remission in Pediatric Ulcerative Colitis

Several randomized controlled trials (RCTs) have affirmed the efficacy of 5-aminosalicylic acid (5-ASA) and sulfasalazine in the acute treatment of mild to moderate exacerbations, as well as in the maintenance of clinical remission. Initially, common practice was to prescribe 5-ASA in three divided doses. Slow release once daily mesalamine with Multi Matrix System (MMX) technology was shown to be effective in induction and maintenance of remission of adult ulcerative colitis (UC). Since transit time of the colon is much slower than the small-bowel, and since the active ingredient should act locally on the colon, less frequent dosing of the regular formulation may also provide sufficient colonic coverage. Indeed, two recent studies among adults with UC suggest that once daily dosing of mesalamine (Pentasa® and Salofalk®) may be as or more effective than twice daily dosing. To date, most RCTs have been conducted among adult patients and efficacy in children has been extrapolated from these data. However, childhood inflammatory bowel disease (IBD) may not be similar to adult onset disease. The prevalence of extensive colitis proximal to the splenic flexure is doubled in pediatric-onset UC compared to adults and extensive disease is consistently associated with more severe phenotype. On the other hand, studies in children with IBD often show better response to therapy than in adults. Therefore, American and European regulating agencies encourage pediatric studies be conducted for all approved drug products. It has been found that less than 50% of children with IBD are adherent with treatment, a figure associated with the understanding of the disease which is generally lower than in adults. Therefore, the advantage of once daily dosing of 5-ASA over twice-daily may be greater in children compares with adults. The investigators hypothesize that once daily dosing of mesalamine is superior in effectiveness to twice daily dosing to induce remission in pediatric mild-moderate UC. We base this hypothesis on data previously found in adults and due to the expected higher adherence rate. This study will compare two groups receiving an identical dose of the same non experimental medication, with the only difference being in the number of doses of the medication!