1 Department of Radiation Oncology, London Health Sciences Centre, London, Canada.
2 Departments of Emergency Medicine, and of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada.
3 Poison and Drug Information Service, Alberta Health Services; Section of Clinical Pharmacology and Toxicology, Alberta Health Services; Department of Emergency Medicine, University of Calgary, Calgary, Canada.
4 Department of Emergency Medicine, McMaster University, Hamilton, Canada.
5 Poison and Drug Information Service, Alberta Health Services; Department of Pediatrics, University of Calgary, Calgary, Canada.
6 Departments of Emergency Medicine and Pediatrics, School of Medicine, University of Colorado Denver, CO, USA.