Adverse events related to medications identified by a Canadian poison centre

Poison centres are an underutilized source of information on adverse events related to medications, including therapeutic errors and adverse drug reactions.

To demonstrate the feasibility of using a poison centres' electronic data to identify and describe adverse events related to medications.

This one-year, retrospective cross-sectional pilot study was conducted at one Canadian Poison Centre. All records from the IWK Regional Poison Centre database in Nova Scotia between November 1, 2007 and October 31, 2008 for unintentional exposures were abstracted for a descriptive data analysis.

An issue related to use of a medication was the main reason for 1,525 (32.5%) of 4,697 eligible calls. Of the 1,525 calls, 970 (63.6%) were coded as 'unintentional-general.' There were 470 (30.8%) calls for unintentional therapeutic errors and 61 (4.0%) for adverse drug reactions. The majority of calls involving medications were judged to have resulted in minimal or no toxic effect (78.4%). However, 3.3% of calls involving adverse drug reactions resulted in admission to a critical care unit (n=2). Approximately 1% of calls involving unintentional therapeutic errors resulted in admission to hospital (n=6).

Calls to poison centres provide a potentially valuable source of information on adverse events related to medications that are likely not reported elsewhere. Establishment of a mechanism to routinely share information from all Canadian poison centres with relevant national drug safety programs (e.g., MedEffect™ Canada) will provide a supplementary source of information and contribute to building capacity for detection of sentinel events and pharmacosurveillance.