Sulfasalazine vs 5-ASA: Treatment Outcomes in Pediatric UC

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I Mansuri et al. J Pediatr Gastroenterol Nutr. 2025;80:988–997. Clinical outcomes of maintenance therapy with sulfasalazine compared to 5-aminosalicylates in children with ulcerative colitis

Methods: This was a retrospective review of children diagnosed with UC between June 1999 and December 2019 at Boston Children’s Hospital. 124 started on sulfasalazine (SZ) and 309 on 5-aminosalicylates (5-ASA). Most patients had mild to moderate disease based on PUCAI score; ~12% had severe disease.

Key findings:

  • At 1 year, 54%, 44.3%, and 36.6% of patients on SZ, 5-ASA, and those who switched, respectively, were in steroid-free remission (p = 0.13)
  • All medication switches due to adverse reactions (24) were from SZ to 5-ASA. No patient was switched from 5-ASA to SZ because of adverse reactions. The non-severe adverse reactions noted were nausea, vomiting, abdominal pain, non-severe skin rash, headache, mild leucopenia, and lymphadenitis. Three patients had serious skin reactions, and one had pancreatitis.
  • SZ tended to have more minor adverse reactions. Except for countering adverse reactions, switching between SZ and 5-ASA did not offer therapeutic benefits. Disease severity at diagnosis predicted early treatment escalation

Discussion Points:

  • SZ offers advantages such as lower cost and availability in suspension form; the suspension form is particularly beneficial for young children and those unable to swallow the solid form of medication.
  • 5-ASA formulations can be almost 10–50 times more expensive than SZ. For example, the wholesale acquisition cost of monthly generic SZ is $30 compared to $274 for generic Lialda, $1131 for generic Pentasa, and $1890 for generic Asacol HD

My take: About 20% of patients had to switch from Sz to 5-ASA due to adverse reactions; though, Sz had a mildly higher response rate (not statistically-significant). Switching between SZ and 5-ASA or vice versa is unlikely to provide much therapeutic benefit; patients who switched agents for medical reasons (rather than reactions) were more likely to require escalation to either a biologic or immune modulator.

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1 thought on “Sulfasalazine vs 5-ASA: Treatment Outcomes in Pediatric UC”

  1. We chnaged over years from Sulfasalazine to Mesalamine or Olsalazine because of allergic reactions and abdominal pain.

    its only sufficient working in left side ore mild UC, not so often in children. The most young patient need additional steroids because of flairs. The Use ist limited by severe side effects, often, not rare, like pancreatitis or elevated Lipase with tommy pain and interstitial Nephritis.

    as a rectal formulation is 5-ASA usefull, Olsalazin has fewer or never severe side effects. Only the Diarrhoea while use is a Limit-Point.

    only in UC + Arthritis is a place for Sulfasalazine.

    Its not cheaper to use a ineffective drug with side effects.

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