Therapeutic drug monitoring was helpful in guiding the decision-making process for children receiving infliximab for inflammatory bowel disease

Aim: This study examined the impact of therapeutic drug monitoring (TDM) on clinical decision-making for children receiving infliximab for inflammatory bowel disease (IBD). Methods: The medical records of children with IBD who had infliximab trough levels (ITLs) measured between January 2013 and December 2015 at two Canadian tertiary-care centres were examined. The indications for TDM, clinical and laboratory disease activity indices and TDM-driven treatment changes to infliximab therapy were documented. Results: We included 107 consecutive serum measurements of ITLs in 73 children (40 boys), with a median age of 16.1years, including 52 with Crohn's disease. TDM was performed due to concerns about clinical disease activity in 24/107 (22.4%) measurements and 83 (77.6%) were ordered as routine tests. Of these, 38 (35.5%) ITLs were suboptimal (<3.5 mu g/mL) and 36 (34.0%) resulted in more frequent doses of infliximab, with subsequent improvements in disease biomarkers. Interval changes were implemented as a result of 34 (32.0%) ITLs, with shorter intervals in 19 (17.0%) cases, and seven (6.5%) ITLs resulted in adding or increasing doses of immunomodulators. In addition, four children were switched to adalimumab. Conclusion: Therapeutic drug monitoring was helpful in guiding the decision-making process for children with IBD on infliximab.