Green et al enrolled 101 (99 evaluable) patients with moderate to severe symptoms of ulcerative colitis (UC) into a randomised, double blind, double dummy trial comparing 6.75 g balsalazide (Colazide) and 2.4 g mesalamine (Asacol) over 12 weeks. The primary endpoint was complete remission defined as absent or mild symptoms with either a normal sigmoidoscopy or a sigmoidoscopy demonstrating erythema and loss of vascular pattern. 62% of balsalazide versus 37% of mesalamine treated patients achieved remission by 12 weeks. In addition, balsalazide treated patients had a shorter median time to complete relief, a higher percentage of symptom-free days, less treatment failures, and fewer serious adverse effects. The authors concluded that balsalazide was “more effective...with more favourable side effect profile”.

This study suggests the clinical superiority of balsalazide over mesalamine in the formulations tested. The context, methodology and interpretations must, however, be viewed in perspective. This trial compared equivalent amounts of 5-aminosalicylic acid (5-ASA) delivered from Colazide and Asacol at currently “approved” doses of Asacol (2.4 g/day in the USA). This is …