Objective To assess the impact of pharmacist intervention in reducing prescribing errors in paediatrics, and to analyse the clinical significance and reasons behind the errors detected.

Methods Cross-sectional epidemiological study analysing the activities of the paediatric pharmacist in a maternity and children's hospital with 180 paediatric beds, between January 2007 and December 2009. The following variables were analysed: impact of the pharmacist's recommendation on patient care, reason for the intervention, clinical significance, type of negative outcome associated with the medication, acceptance rate, medication involved, intervention detection date and observations.

Results A total of 1475 interventions in medical orders for 14 713 paediatric patients were recorded (40 (2.9%) extremely significant interventions and 155 (11.1%) very significant interventions). There were 1357 prescribing errors, 833 of which were dosing errors. 2.2% of the errors detected were potentially fatal (30 cases) and 14.3% (194 cases) were clinically serious. The main reason for interventions was detection of a dosage between 1.5 and 10 times higher than that recommended. The overall rate of acceptance of the pharmacist's suggestions was 94.3%. The pharmacist carried out an average of 0.019 interventions per patient day throughout the study period.

Conclusion Interventions by a clinical pharmacist had a major impact on reducing prescribing errors in the study period, thus improving the quality and safety of care provided.