Paediatric adverse drug reaction reporting: understanding and future directions.

BACKGROUND Severe adverse drug reactions (ADRs) are an important cause of childhood morbidity and mortality. 95% of ADRs are likely not reported, less than 25% of marketed drugs can be advertised as safe and effective in children; yet over 50% of Canadian children receive prescription drugs annually. OBJECTIVES To increase understanding of reported ADRs in Canadian children. METHODS A retrospective analysis of 1193 suspected ADRs reported to Health Canada (January 1998 - May 2002). These data were a paediatric subset of the Canadian Adverse Drug Reaction Information System database. RESULTS 58.6% of ADRs were for children over 13 years. 61% of reports were defined by Health Canada as serious. Case outcomes include: death (n=41) and recovered with sequelae (n=14). 4 reports of interacting drugs had fatal outcomes. Drugs most frequently cited include: isotretinoin (n=56), paroxetine (n=42), methylphenidate (n=41), amoxicillin (n=40), and valproic acid (n=32). Most frequent reaction descriptors include: psychiatric disorders (isotretinoin and paroxetine) and nervous system disorders (valproic acid, bupropion and carbamazepine). Causal links between suspected ADRs and clinical outcomes have not been established. CONCLUSIONS Current ADR reporting is insufficient to improve patient safety. More detailed reporting, including case outcomes, is needed. Mandatory ADR reporting is unlikely to improve underreporting. Trained surveillance personnel located in major health centres and solely dedicated to ADR reporting may provide a more accurate determination of ADRs in Canadian children.