olsalazine

Olsalazine is an anti-inflammatory medication used in the treatment of ulcerative colitis. It is sold under the brand name Dipentum.

Olsalazine itself is a prodrug of mesalazine (5-aminosalicyclic acid or 5-ASA) and is not absorbed in the small intestine. Instead it continues through to the colon where it is cleaved into two molecules of 5-ASA by azoreductases produced by colonic bacteria. Olsalazine thus exerts its anti-inflammatory effect by its colonic breakdown into 5-ASA which inhibits cyclooxygenase and lipoxygenase thereby reducing prostaglandin and leukotriene production.