Background: Unintended overdoses of opiate medications are potentially lethal events. Monitoring patients for oversedation is fundamental to ensuring safe use of opiates, and the timing of this evaluation is guided by the onset of action, time to max effect and duration of action of the opiate. The study's aim was to describe the timing of oversedation in relation to the predicted duration of action of the administered opiate.

Methods: This study was conducted as a retrospective review of all opiate-related oversedation events during a 2-year period involving patients admitted to an urban teaching hospital.

Results: Of the 53 opiate-related oversedation events evaluated, 47% occurred after the predicted maximal duration of action of the administered opiate.

Conclusion: Opiate-induced oversedation routinely occurs after predicted based upon duration of action. The study findings have profound implications upon nursing practice regarding duration of time required to monitor for opiate-induced oversedation.