Causality, severity and avoidability of adverse drug reactions in children: An 11‐year review

Aims Adverse drug reactions (ADRs) are a frequent cause of hospital presentations and confer increased healthcare costs. This study aimed to assess the causality, severity and avoidability of ADRs in hospitalized children. Methods This is an 11‐year retrospective cohort study of children aged 0–18 years who were either admitted to a quaternary paediatric hospital due to an ADR or who experienced such a reaction during their hospital stay. Those who presented with intentional drug misuse or overdose were excluded. Causality, severity and avoidability were assessed using the Naranjo criteria, Hartwig scale and Modified Schumock and Thornton scale, respectively. ADRs were categorized as Type A (dose‐related) or Type B (idiosyncratic). Results Of 599 children with ADRs, the median age was 8.7 years (3 weeks to 18 years). Most ADRs (74%) were mild, with 25% moderate and 1% severe. The most commonly implicated drugs were antimicrobials (46%), analgesics (9%), antiepileptics (8%) and monoclonal antibodies (6%). Type A reactions comprised 44%, with neurological symptoms to metoclopramide (22%) being the most common. Type B reactions (56%) most commonly occurred with antimicrobials (63%). Overall, 15% of ADRs were potentially avoidable: 9% definitely and 6% probably avoidable. Most avoidable ADRs were due to failure to consider documented allergies, inappropriate dosing, drug interactions or not applying preventative measures (e.g., premedication). Conclusion Our study shows that one in six paediatric ADRs were potentially avoidable, highlighting the need for improved ADR documentation, pharmacovigilance and clinician education.