Oral and topical 5-aminosalicylic acid (mesalazine) in inducing and maintaining remission in mild-moderate relapse of ulcerative colitis: one-year randomised multicentre trial.

BACKGROUND

The association of oral 5-aminosalicylic acid (mesalazine) and enema is effective in treatment of mild-moderate forms of ulcerative colitis. However no study has been aimed at determining optimal duration of this association in active ulcerative colitis.

AIM

To determine whether longer duration of therapy: 1. increases the rate of patients achieving remission, and 2. reduces relapse rate during the maintenance period in patients in remission.

PATIENTS AND METHODS

A total of 149 patients, (89 male, 60 female), were randomly assigned to a regimen with 5-aminosalicylic acid tablets 2.4 g/day associated with 5-aminosalycilic enema 2 g/day for a 4-week (n = 73) or 8-week regimen (n = 76). After this acute therapy, patients were submitted to clinical, endoscopic and histological examinations and those in remission were assigned to a follow-up (maintenance) period with oral mesalazine alone at a dosage of 1.2 g/day. A clinical visit, including laboratory tests, at 6 months and an endoscopic-histological control at 12 months were carried out to exclude symptoms and endoscopic-histological signs of activity. Relapse of disease, i.e., presence of clinical symptoms or abnormal laboratory tests, was confirmed by endoscopy and histology.

RESULTS

At end of acute phase, clinical, endoscopic and histological remission was comparable in the two groups: 42/76 (55%), in the 4-week, and 47/73 patients (64%), in the 8-week regimen. No difference was found stratifying patients according to extension of disease. Of these 89 patients in remission, 75 (34 from 4-week regimen; 41 from 8-week regimen) completed 12 months' follow-up. At end of follow-up, a similar percentage of patients in the 4-week regimen (50%) and 8-week regimen (51%) were still in remission. No significant difference between cumulative relapse rates of the two groups was found. Stratifying patients according to extension of disease, in the 8-week regimen group, those with left-sided colitis showed a higher remission rate than that of patients with diffuse colitis (66% versus 35%, p < 0.05). All regimens were well tolerated by most patients during the entire study period.

CONCLUSIONS

An additional 4 weeks of topical treatment does not increase the remission rate in patients with mild-moderate active ulcerative colitis but seems to reduce the probability of relapse in patients with left-sided colitis.