Coated mesalazine (5-aminosalicylic acid) versus sulphasalazine in the treatment of active ulcerative colitis: a randomised trial.

OBJECTIVE: To assess the safety and efficacy of a preparation of mesalazine (5-aminosalicylic acid) coated with a pH dependent resin (Eudragit L) as compared with sulphasalazine in patients with active mild to moderate ulcerative colitis. DESIGN: Eight week randomised double blind parallel group study. SETTING: Forty six gastroenterology outpatient clinics in seven countries. PATIENTS: Two hundred and twenty patients aged 18-70 who met the following criteria: clinical activity index greater than or equal to 6 and endoscopic index greater than or equal to 4; no concomitant treatment for ulcerative colitis; no hypersensitivity to salicylates or sulphonamides. Of the 164 patients eligible for efficacy analysis, 87 received the coated preparation of mesalazine and 77 sulphasalazine. Most of the remaining patients (28 in each group) were ineligible for the efficacy analysis because of treatment with steroid enemas. All pretrial characteristics were comparable in the two treatment groups. INTERVENTIONS: Coated mesalazine (Mesasal) 1.5 g daily or sulphasalazine 3.0 g daily for eight weeks. Compliance monitored by pill counts. END POINT: Clinical and endoscopic remission. MEASUREMENTS AND MAIN RESULTS: Clinical activity measured by daily diary cards, assessment by investigators, and laboratory findings. Endoscopic evaluation at week 8. After four weeks 50 of 70 patients (71%) taking coated mesalazine and 38 of 58 (66%) taking sulphasalazine had achieved remission of their disease by eight weeks remission rates were 74% (37/50 patients) and 81% (35/43) in the two treatment groups respectively. Endoscopic remission at eight weeks was recorded in 20 of 41 patients (49%) taking coated mesalazine and 18 of 38 (47%) taking sulphasalazine. There was a higher incidence of adverse events among patients taking sulphasalazine (25/105; 24%) than among those taking coated mesalazine (16/115; 14%). CONCLUSION: Mesalazine coated with Eudragit L is a safe, logical alternative to sulphasalazine.