Year 1977: The active component of sulphasalazine is 5-aminosalycilic acid

In 1941, Nana Schwartz had introduced salazopyrin combined with an antibiotic (a sulfamide) with a presumed analgesic (5-aminosalycilic acid) to control as far as possible the, presumed infectious, rheumatoid arthritis of the King of Sweden. She got it right with an immunomodulating molecule that we still use. Some patients with chronic diarrhoea improved, and it began to be used in ulcerative colitis, with the Truelove group being that which contributed the most to finding evidence of its usefulness in ulcerative colitis. But, what really was the active component? This is not a trivial question, since salazopyrin was associated with significant adverse events on occasion or if the dose was high. This study is a wonder of ingenuity: patients with colitis were treated with salazopyrin, sulfapyridine or mesalazine: mesalazine enemas were equally effective as the mother molecule, while sulfapyridine alone was clearly inferior. This idea led to the development of mesalazines that we use today, and that are the basis of treatment for most patients with ulcerative colitis, with one of the safest drugs that we use in digestive medicine.