Cyclooxygenase inhibitors, NSAID - Mesalazine
Mesalamine also called mesalazine or 5-aminosalicylic acid has antiinflammatory properties in the colon and is used in the treatment of ulcerative colitis (Crohn's disease). Its mechanism of action is complex and as yet incompletely known: in addition to cyclo-oxygenases, it could inhibit lipoxygenases.
Initially, mesalazine was prescribed in the form of sulfasalazine, a diazo derivative formed of mesalazine and sulfapyridine, an antibacterial sulphamide. The latter did not have an antibacterial role, but played in fact a protective role for mesalazine to enable it to reach the colon without being absorbed. In the colon, salazopyrine is hydrolyzed to sulfapyridine and mesalazine.
A preparation of mesalazine as microgranules, which reduces its absorption in the small intestine, allows sufficient concentrations to reach the colon where it carries on its activity .
Mesalazine |
PENTASA * Capsules
ROWASA * Rectal suspension enema |
Olsalazine, a mesalamine prodrug consists of two molecules of 5-aminosalicylic acid bound together by an azo bridge. Taken by oral route, olsalazine is poorly absorbed by the digestive tract and reaches the colon in high concentration. Olsalazine arrives intact in the colon where it is cleaved into two molecules of 5-aminosalicylic acid by azo-reductases secreted by bacteria.
Olsalazine |
DIPENTUM * Capsules |
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