Measurement of colonic mucosal concentrations of 5-aminosalicylic acid is useful for estimating its therapeutic efficacy in distal ulcerative colitis: comparison of orally administered mesalamine and sulfasalazine

Inflamm Bowel Dis. 2001 Aug;7(3):221-5. doi: 10.1097/00054725-200108000-00007.


Objectives: Oral 5-aminosalicylic acid (5-ASA) preparations have been used frequently in the treatment of ulcerative colitis. However, there have been few reports investigating the relationship between colonic mucosal concentrations of 5-ASA and its clinical efficacy when oral sulfasalazine or 5-ASA compounds were administered. The aim of this study is to compare the mucosal concentrations of 5-ASA ensured by sulfasalazine or mesalamine, and to define the clinical significance of the measurement of 5-ASA concentrations in the treatment of distal ulcerative colitis.

Materials and methods: Biopsies were taken from the rectum and sigmoid colon of the oral sulfasalazine group (n = 13) and the slow-release 5-ASA (mesalamine) group with (n = 5) or without (n = 11) rectal administration of 5-ASA. High-pressure liquid chromatography was used to measure the tissue concentrations of 5-ASA and its metabolites. We compared the 5-ASA concentrations of the sulfasalazine group with the mesalamine group. Furthermore, we analyzed the relationship between tissue 5-ASA concentrations and the Disease Activity Index (DAI).

Results: The concentrations of 5-ASA and acetyl-5-ASA in the sulfasalazine group were higher than those in the group taking oral mesalamine alone (p < 0.01). The concentration of 5-ASA was much higher in the patients who received oral and rectal mesalamine in an enema than in the patients who had oral mesalamine alone. There was a significant inverse correlation between the DAI and concentrations of 5-ASA in the rectum (r = 0.712, p < 0.001).

Conclusions: We demonstrated that the colonic mucosal concentration of 5-ASA was significantly higher in the sulfasalazine group than in the mesalamine group. Furthermore, the concentrations of mucosal 5-ASA may be a good marker for the estimation of its efficacy in the treatment of ulcerative colitis.

Publication types

  • Comparative Study

MeSH terms

  • Administration, Oral
  • Adult
  • Anti-Inflammatory Agents, Non-Steroidal / administration & dosage
  • Anti-Inflammatory Agents, Non-Steroidal / pharmacology
  • Anti-Inflammatory Agents, Non-Steroidal / therapeutic use*
  • Colitis, Ulcerative / drug therapy*
  • Female
  • Humans
  • Intestinal Mucosa / drug effects
  • Intestinal Mucosa / metabolism*
  • Male
  • Mesalamine / administration & dosage
  • Mesalamine / pharmacology
  • Mesalamine / therapeutic use*
  • Middle Aged
  • Sulfasalazine / administration & dosage
  • Sulfasalazine / pharmacology
  • Sulfasalazine / therapeutic use*
  • Treatment Outcome


  • Anti-Inflammatory Agents, Non-Steroidal
  • Sulfasalazine
  • Mesalamine