532 PHARMACOKINETICS OF SULFAPYRIDINE (SP) AND ACETYL SULFAPYRIDINE (ASP) IN PEDIATRIC PATIENTS WITH INFLAM MATORY BOWEL DISEASE (IBD)

Abstract

Sulfasalazine is widely used in treating IBD in children; the side effects are thought to be related to the serum concentration of SP and ASP. The pharmacokinetics of SP and ASP were studied in 15 prepubertal children with IBD. The patients were on maintenance sulfasalazine therapy, 30 to 70 mg/kg divided to 2 doses/day. Five patients were studied both during active disease and in remission. Serum samples were drawn at 0,3,6,9 hours after the a.m. dose. SP and ASP concentrations were measured by high pressure liquid chromatography. Acetylator status was determined by % of metabolites in acetylated form (>40%=rapid, <40%=slow). Slow acetylators had higher steady state concnetrations (Cp^ss) of SP metabolites (p<.05), area under curve (AUC)_(total) (p<0.025), AUC_(SP) (p<0.001). AUC_(total) & AUC_(SP) were significantly higher in patients in remission than those in active phase (p<.05). Disease activity and acetylator status had no effect on AUC_(ASP). Patients studied during both relapse and remission had a significantly higher Cp^ss of SP during remission. No correlation was found between SP concentrations and side effects.

Conclusion: prepubertal children with active IBD have lower Cpss of SP metabolites compared to quiesent disease, independent of acetylator status. (Supported in part by UB Research Foundation #1502082C).

Log in or create a free account to read this content

Gain free access to this article, as well as selected content from this journal and more on nature.com

Access through your institution

or

Sign in or create an account

Continue with Google

Continue with ORCiD