16.04.1 Mesalazine

Drugs related to the salicylates (i.e. aspirin), 5-aminosalicylates, such as mesalazine, are used in the treatment of inflammatory bowel disease.  Mesalazine inhibits both the cyclooxygenase pathway and lipooxygenase pathway,(Figure 16.6), whereas the NSAIDs only inhibit the cyclooxygenase pathway.  Thus, mesalazine inhibits the production of prostaglandins in the cyclooxygenase pathway, which have a relatively minor effect in inflammation.  Mesalazine also inhibit the lipooxygenase pathway to reduce the levels of leukotrienes, which have a major role in inflammation. 

Figure 16.6 Mechanism of action of mesalazine (Copyright QUT, Sheila Doggrell)

Mesalazine is effective in mild or moderate active ulcerative colitis, but is a less successful treatment in severe ulcerative colitis.  Mesalazine is also less useful in Crohn’s disease.  Mesalazine alone is absorbed before the colon, which reduces its effectiveness.  Thus, mesalazine is used in enteric coated tablets to reduce any absorption from the stomach.

Pharmacology InOneSemester,
Mar 24, 2015, 10:31 PM