The World Health Organization's ATC classification organizes medical drugs based on therapeutic properties, chemical composition, and anatomy. It helps make essential medicines readily available globally and is widely used in the pharmaceutical industry.
The DDD is the assumed average maintenance dose per day for a drug used for its main indication in adults. The DDD is a unit of measurement and does not necessarily reflect the recommended or Prescribed Daily Dose. Therapeutic doses for individual patients and patient groups will often differ from the DDD as they will be based on individual characteristics (such as age, weight, ethnic differences, type and severity of disease) and pharmacokinetic considerations.
Olsalazine is bioconverted to 5-aminosalicylic acid (5-ASA), which has anti-inflammatory activity in ulcerative colitis. The conversion of olsalazine to mesalamine (5-ASA) in the colon is similar to that of sulfasalazine, which is converted into sulfapyridine and mesalamine. The mechanism of action of mesalamine (and sulfasalazine) is unknown, but appears to be topical rather than systemic.