Background and purpose: The Eudragit S formulation of delayed-release 5-aminosalicylic acid (5-ASA), Asacol tablets (AT), has limited efficacy in maintaining remission in patients with inflammatory bowel disease (IBD). This study evaluated the effect of switching patients with unsatisfactory results under treatment with AT to a microgranule delayed-release formulation of 5-ASA, Pentasa tablets (PT).
Methods: A 12-week, open drug-switching study was conducted in 15 IBD patients, including 9 with ulcerative colitis (UC) and 6 with Crohn's disease (CD) who were evaluated at the time of switching from routine AT (2.4 g/day) treatment (for more than 3 months) to PT (4 g/day). UC patients were those under AT remission maintenance and they were defined as prone-to-relapse because of endoscopy scores > or = 2. CD patients were those under acute treatment with AT who had not attained a complete remission. The primary endpoint was the change in UC Disease Activity Index (UC-DAI) or the CD Activity Index scores after switching to PT therapy. Drug safety profile and patient acceptability were secondary endpoints.
Results: Twelve weeks after switching to PT treatment, the mean (+/- SEM) UC-DAI score was reduced significantly, from 8.18 +/- 0.58 to 6.81 +/- 0.72 (p = 0.013) in UC patients. Subcategory scores indicated improvements in endoscopy scores and in physician global assessment. Though the change in clinical outcomes did not reach significance for CD patients, a trend towards a therapeutic benefit was observed. No adverse event was observed during the 12-week clinical trial.
Conclusion: PT may provide a better alternative for IBD patients with unsatisfactory response to AT therapy.