1. IWK Regional Poison Center, Halifax, NS, Canada, and Experimental Therapeutics, University of California, San Francisco; IWK Regional Poison Center, 5850/5980 University Avenue, PO Box 9700, Halifax, NS, B3K 68R, Canada
2. Departments of Pediatrics, The Permanente Medical Group, Kaiser Foundation Hospital, Santa Clara CA, and Stanford University School of Medicine, Stanford
3. California Poison Control System, San Francisco, CA
4. Division of Clinical Pharmacology and Experimental Therapeutics, University of California, San Francisco, CA