A decade of real-world clinical experience with 8-week azithromycin-metronidazole combined therapy in paediatric Crohn's disease.

Objectives: The aim of our study was to assess the effectiveness and side-effect profile of a combination of azithromycin and metronidazole (CD AZCRO) as alternative induction therapy for 8 weeks in mild to moderately active paediatric Crohn's disease (CD).

Methods: We performed a retrospective cohort study (November 2012 to July 2023) of a regional paediatric inflammatory bowel disease service. Disease activity, faecal calprotectin (FC), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), haematological parameters and albumin were collected at baseline, 8 and 16 weeks. At Week 8, patients were divided based on (paediatric Crohn's disease activity index) score and inflammatory markers (blood and stool) into: Group 1 clinical remission and Group 2 non-remission.

Results: A total of 48 patients were initially identified of whom 44 were included in the intention-to-treat analysis. After 8 weeks, the overall remission rate was 64%. Of the 38 patients who completed the CD AZCRO course, 28 patients (74%) entered remission (Group 1) and 10 (26%) did not (Group 2). At baseline a shorter disease duration, low weight z score and higher inflammatory burden (ESR, platelets and FC levels) were observed in Group 2. After 8 weeks, Group 1 showed improved CRP levels and higher albumin and haemoglobin levels than Group 2. Median FC declined significantly from 650 mcg/g at baseline to 190 mcg/g at Week 8 in Group 1 (p < 0.001). At 16 weeks, 23/28 patients (82%) continued in clinical remission. Nausea and vomiting were reported in 4/44 patients.

Conclusions: Our real-world data demonstrate that CD AZCRO represents an alternative induction therapy for mild to moderate paediatric CD.