Background & aims: The efficacy of 5-aminosalicylic acid (mesalamine) in the treatment of flare-ups of Crohn's disease is controversial. In previous studies, different locations and pathological behavior of Crohn's disease could have obscured the efficacy of these drugs that deliver their substance in different intestinal sites. The present study tested two different mesalamine formulations with 6-methylprednisolone in mild to moderate active Crohn's ileitis.

Methods: Ninety-four patients with Crohn's ileitis (Crohn's Disease Activity Index [CDAI], 180-350) were randomly assigned to receive for 12 weeks mesalamine tablets, 4 g (35 patients); mesalamine microgranular preparation, 4 g (28 patients); and 6-methylprednisolone, 40 mg (31 patients). Mesalamine microgranular preparation was a gelatin capsule containing 400 mg of mesalamine microgranules coated with Eudragit S, which has been shown to deliver the drug in the terminal ileum.

Results: Patients taking mesalamine tablets experienced a decrease of CDAI median score value of 113.5 (95% confidence interval [CI], 33-149) compared with 123 (95% CI, 77-155) in the mesalamine microgranular group and 154 (95% CI, 99-197) in the 6-methylprednisolone group (P = 0.07 [NS]). Remission at the final visit occurred in 19 of 31 (61%) patients taking steroids compared with 21 of 35 (60%) patients taking mesalamine tablets and 22 of 28 (79%) patients taking microgranular mesalamine (NS). Five patients on steroids were withdrawn because of side effects, and a case of pancreatitis was related to microgranular mesalamine.

Conclusions: Mesalamine in microgranular formulation seems to be equally as effective as a standard dosage of steroids in the treatment of the mild to moderate form of Crohn's ileitis.