Changes in Patient Reported Pain Measures With the Citrate-free Adalimumab Formulation in Pediatric Inflammatory Bowel Disease Patients

Inflammatory bowel diseases (IBD) are characterized by chronic inflammation in the gastrointestinal tract. The perception of pain in children is very complex and involves psychological, physiological, behavioral, and developmental factors. For children with chronic diseases, the medical procedures and treatments are often painful, unexpected, and heightened by situational stress and anxiety leading to an overall unpleasant experience. Pain and injection-site reaction are major predictors of nonadherence to antitumor necrosis factor treatment. The most commonly reported adalimumab adverse event was injection-site reaction. This study compares reported pain in pediatric IBD patients between the 2 formulations using a visual analog scale (VAS). Our hypothesis is that the citrate-free formulation would have significantly less injection-site pain than the original formulation. We evaluated injection-site pain in 6- to 17-year olds with IBD between the original formulation and citrate-free using the Faces Pain Scale-Revised for pain from 0 (no pain) to 10 (worse pain possible). Ninety-five percent of patients reported that their pain score was greater than 3 with original formulation, while only 5% of them reported their pain score was greater than 3 with citrate free. The McNemar’s test showed significant difference in the pain score between the 2 types of injection (P < 0.0001).