Active surveillance of serious adverse drug reactions in New Zealand children
- 1NZ Pharmacovigilance Centre, Department of Preventive and Social Medicine, University of Otago, Dunedin, New Zealand
- 2Queensland Children's Medical Research Institute, Royal Children's Hospital, University of Queensland, Queensland, Australia
- 3Department of Women's and Children's Health, University of Otago, Dunedin, New Zealand
- Correspondence to Desiree Kunac, NZ Pharmacovigilance Centre, Department of Preventive and Social Medicine, University of Otago, Dunedin 9054, New Zealand;
Contributors DK contributed to the conception and design, acquisition, analysis and interpretation of data, drafting and revising the manuscript, and now letter. MT, KG and DR contributed to conception and design, analysis and interpretation of data, and helped with revising the manuscript, and now letter, critically for important intellectual content. All authors approved the final version of the letter.
- Accepted 2 April 2012
- Published Online First 6 May 2012
Children are at risk of developing adverse drug reactions (ADRs),1 yet few are reported through postmarketing surveillance schemes monitoring safety in this vulnerable population.2 We therefore developed an active surveillance system targeting New Zealand paediatricians to enhance serious ADR notifications in children aged <16 years.
A priori, paediatricians were given written case definitions of serious ADRs, which they then notified to the New Zealand Paediatric Surveillance Unit (NZPSU) using standard methodologies described elsewhere.3 Cases were defined as noxious and unintended responses associated with the use of prescription, non-prescription and complementary medicines at any dose and resulting in hospitalisation or an Emergency Department visit, prolongation of hospitalisation, persistent or significant disability, or death in children aged <16 years. Reactions to vaccines, blood products, medical devices, poisonings or self-administered overdoses were excluded. The New Zealand Health and Disability Multi-region Ethics Committee approved the study.
During the 3-year period (1 August 2007–31 July 2010), 49 notifications were received; two however were in error and for 11 no further details were provided. Of the remaining 36 reports, 18 were excluded as they did not meet the case definition and involved vaccines (6), age >16 years (2), accidental overdose (1) or were deemed by the medical assessor as ‘not serious’ (9). Therefore, 18 reports met the inclusion criteria (table 1).
Thirteen new reports (72%) were received by the NZPSU system without prior notification to the Centre for Adverse Reactions Monitoring (CARM), New Zealand's national ADR reporting programme operated by the New Zealand Pharmacovigilance Centre. Importantly, for 12 cases, a medical ‘danger’ or ‘warning’ notation was entered into the national Medical Warning System to safeguard the child against future, similar ADRs. No fatal ADRs or cases relating to complementary therapies were reported.
While in absolute terms the numbers of reports received annually through the NZPSU are small, just four of these would have been detected had only the CARM system been operating. Furthermore, the 13 new cases represent 10% of serious paediatric ADR reports to CARM during the study period. New Zealand has consistently had the highest country rate of reporting per population based on the reports it submits along with over 100 other countries to the WHO Programme for International Drug Monitoring's pooled database.4 Despite this high level of performance achieved through the national CARM programme, the NZPSU enhanced reporting illustrates how stepwise monitoring improvement modalities can add further value to pharmacovigilance. Consequently, methods to streamline notifications are being investigated, such as secure web-based reporting instead of hard copy submissions, while targeting paediatric hospital pharmacist networks will help determine if additional serious ADR events can be captured.
This small case series identified serious ADRs in New Zealand children that have gone unreported previously, including individuals where medical ‘danger’ or ‘warning’ signals had not been entered into the national Medical Warning System. While the NZPSU proved useful, additional mechanisms may be required to ensure more complete capture of cases.
The authors thank all New Zealand paediatricians and the staff of the New Zealand Paediatric Surveillance Unit for their assistance with the study.
Competing interests None.
Provenance and peer review Not commissioned; externally peer reviewed.