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.