Prospective identification and causality evaluation of suspected adverse drug reactions in neonates.

Neonates experience adverse drug reactions (ADRs), but under-reporting of suspected ADRs to national spontaneous reporting schemes in this population is particularly high. A prospective observational study collected suspected neonatal ADRs at a tertiary neonatal unit. Cases were analysed for causality by six assessors using three existing methods. Sixty-three suspected ADR cases were identified in 35/193 neonates (18.1%). The proportion of suspected ADRs where the drug was prescribed "off-label" was 30/68 (44.1%). When 34 cases were assessed for causality using three methods, global kappa scores of less than 0.3 for each tool suggested only "fair" inter-rater reliability. Neonatal ADRs can be captured and occur from a variety of drugs affecting many organ systems. The current tools for assessing causality need to be adapted before they can reliably assess neonatal ADRs.