Gastroenterology & Hepatology (G&H)Therapeutic Drug Monitoring in Adolescents and Children with Inflammatory Bowel Disease

🎓 Expert Commentary / Peer Perspective

Children with inflammatory bowel disease face changing drug exposure as they grow, gain weight, and experience fluctuations in inflammation. This narrative review examines proactive therapeutic drug monitoring to individualize advanced therapy and preserve treatment response. Evidence is strongest for infliximab and adalimumab, including randomized pediatric adalimumab data. Monitoring targets for other biologics rely more heavily on observational studies and adult extrapolation; the review does not establish equivalent benefit across drug classes.

Clinical Considerations

• In PAILOT, proactive adalimumab monitoring produced 82% versus 48% corticosteroid-free clinical remission at 72 weeks among induction responders with Crohn’s disease.
• Younger age, smaller body size, hypoalbuminemia, and greater inflammatory burden can increase clearance, making standard dosing insufficient for some children.
• Induction, maintenance, and perianal disease require different exposure targets; a single trough threshold does not fit every treatment setting.
• Vedolizumab and ustekinumab exposure-response findings are less definitive; pediatric target concentrations remain incompletely validated and often reflect adult evidence.
• IL-23 inhibitor monitoring has uncertain clinical value because assays exist without established concentration targets linked to treatment outcomes.
• The authors favor preemptive escalation in selected high-risk patients, but comparative safety versus adjunctive immunomodulators is not established by this review.

Practice Applications

• Review growth, weight changes, albumin, inflammatory activity, and disease phenotype with pediatric gastroenterology when assessing possible underexposure.
• Interpret drug concentrations alongside symptoms, objective disease measures, and antidrug antibodies rather than treating a laboratory threshold alone.
• Distinguish anti-TNF monitoring evidence from less-established strategies for newer biologics; avoid transferring targets between agents or formulations.
• Discuss sampling schedules, treatment continuity, and insurance barriers with families and the specialty team before planned dose adjustments.