Budesonide. A review of its pharmacological properties and therapeutic efficacy in inflammatory bowel disease.

Budesonide is a glucocorticoid with high topical activity, but low systemic bio-availability which results in reduced systemic effects in comparison with other glucocorticoids. To date, it has been evaluated for use in patients with inflammatory bowel disease when administered either orally as a controlled ileal release formulation or rectally as an enema. In comparative trials, daily treatment with budesonide enema 2 mg/100ml for 4 weeks produced endoscopic remission or improvement in 46 to 84% of patients with active distal ulcerative colitis and/or proctitis and histological remission or improvement in 45 to 68%. In general, this regimen was effective as regimens of hydrocortisone, methylprednisolone, prednisolone or mesalazine (5-amino-salicylic acid, mesalamine) enemas, but caused less suppression of plasma cortisol levels than the other glucocorticoids. Oral treatment with controlled release budesonide 9 mg/day for 8 weeks produces clinical remission in 42 to 67% of patients with active Crohn's disease of the ileum, ileocaecal region and/or ascending colon and significantly reduces Crohn's disease activity index scores compared with baseline and placebo. Results of a quality-of-life questionnaire reflected these clinical improvements. Budesonide has similar efficacy to prednisolone. Response to budesonide is maintained after dosage tapering at 8 weeks. Compared with placebo, maintenance treatment with oral budesonide 3 or 6 mg/day increases the duration of remission in patients with Crohn's disease, but does not appear to affect the 1-year relapse rate. Thus, budesonide, administered rectally to patients with distal ulcerative colitis or proctitis or orally to patients with Crohn's disease of the ileum, ileocaecal region and/or ascending colon, is a favourable option for the treatment of acute exacerbations of inflammatory bowel disease. Because of the low incidence of adverse glucocorticoid-related effects associated with oral budesonide, it may also be a useful agent for longer term maintenance therapy if further clinical trials confirm its efficacy in this indication.