A new mesalazine gel enema in the treatment of left-sided ulcerative colitis: a randomized controlled multicentre trial

Background: A new mesalazine rectal gel preparation (without propellant gas) has been recently developed to improve topical treatment in distal ulcerative colitis. Aim: To evaluate the efficacy, safety and patient tolerability of mesalazine gel enema compared with mesalazine foam enema in the treatment of patients with acute left-sided ulcerative colitis. Methods: In a randomized multicentre investigator-blind parallel group trial, 103 patients with mild to moderate left-sided colitis or proctosigmoiditis were randomly allocated to mesalazine 2 g gel enema (n = 50 evaluable patients) and mesalazine 2 g foam enema (n = 53 evaluable patients) for 4 weeks. Clinical symptoms, endoscopic and histological findings were assessed at entry, 2 and 4 weeks. Patients' evaluation of treatment tolerability and acceptability was assessed at 2 and 4 weeks. Results: After 4 weeks of treatment, clinical remission was achieved by 76% of mesalazine gel enema-treated patients and 69% of patients treated with mesalazine foam enema (P = 0.608). Endoscopic remission rates at week 4 were 51 and 52% for the mesalazine gel and foam enemas, respectively (P = 0.925). Histological remission was achieved by 30% of patients in both groups. Patients reported that the new mesalazine gel preparation was significantly better tolerated than the foam enema. Patients in the foam group had significantly more difficulty in retention (25% vs. 6%, P < 0.05), abdominal bloating (50% vs. 26%, P < 0.005) and discomfort during administration (48% vs. 26%, P < 0.05). Conclusion: The new mesalazine gel enema is efficacious and significantly better tolerated than the mesalazine foam enema.