Frequency and preventability of adverse drug reactions in paediatric patients.

Purpose: To evaluate the frequency, severity and preventability of adverse drug reactions (ADRs) in paediatric patients during the 6-year period from 1 January 1994 to 31 December 1999.

Methods: Data on patient demographics, documented allergies, suspected drug, American Hospital Formulary Service drug classification and dosage regimen were collected retrospectively from ADRs reported to a hospital surveillance programme. ADRs were categorised by severity, preventability and causality. Analysis was conducted by Chi-square and Wilcoxon rank sum (Mann-Whitney) tests.

Results: During the 6-year period, 565 ADRs were reported at a rate of 0.85 ADRs per 100 admissions. The mean patient age was 9.6 years. No history of allergies was documented in 87.4% of the cases, although 2.8% of patients had a documented allergy to the suspected medication. Opioids (narcotics) [n = 65, 11.5%], anticonvulsants (n = 67, 11.9%) and antibiotics (n = 149, 26.4%) were the most frequently implicated drug classes. Over 50% of the reported ADRs resulted in treatment intervention and/or temporary patient harm and of these, 73% required drug therapy. Causality was classified as 'definite' (44.1%), 'probable' (49.9%) or 'possible' (6.0%). Of the reported ADRs, 20.7% were preventable.

Conclusions: ADRs resulted in treatment intervention or temporary patient discomfort in >50% of patients. The incidence of preventable ADRs is similar to that found in adult literature. No single drug caused >5% of reported ADRs. Opioids, anticonvulsants and antibiotics were the most common drug classes associated with ADRs. Thus, strategies targeting these drug classes and interventions during the medication ordering and administration processes may reduce the number of ADRs and possibly the associated costs. Even though preventable ADRs may not be entirely eliminated, the goal should be to increase ADR awareness and encourage early detection and intervention to minimise patient discomfort.