The main adverse effects of salazopyrin are usually dose-dependent and mild. Exceptionally, idiosyncratic reactions occur which may be life-threatening.
Case reports: Two 10-year old children were treated for Crohn's disease with salazopyrin. At day 21 and day 10 respectively, pharyngitis, rash, and fever were noted. During the following days, high-grade fever persisted, while jaundice, severe cytolysis and acute liver failure also occurred. Drug hepatotoxicity was suspected and salazopyrin was withdrawn on day 29 and day 24 respectively. Development of hepatic encephalopathy led to urgent liver transplantation in both cases.
Conclusion: Salazopyrin is a possible cause of fulminant immunoallergic hepatitis. Prompt therapeutic interruption is urgent, but it may not alter the outcome and or preclude the need for liver transplantation. We suggest that salazopyrin therapy be avoided in pediatric inflammatory bowel disease whenever possible, and that the use of pure amino-salicylates be preferred.