Opioid analgesic dose and the risk of misuse, overdose, and death: A narrative review

Purpose: Despite the rise in serious adverse events paralleling increased prescription opioid analgesic use in the United States over the past 2 decades, the association between opioid analgesic dose and the risk of serious adverse health outcomes is incompletely characterized. We sought to synthesize the medical literature for observational studies examining the association between opioid analgesic dose and the risk of serious adverse health outcomes, with particular attention to the outcomes of misuse, abuse, addiction, overdose, and death.

Methods: Searching MEDLINE using PubMed and bibliography review, we identified 22 observational studies published between 2000 and 2015 that assessed the association between opioid analgesic dose and the risk of serious adverse health outcomes. Some of these studies had significant methodological limitations. Twelve reviewed studies examined the outcomes of misuse, overdose, or death; no studies examining the risk of addiction or abuse met our criteria for inclusion.

Results: The results of multiple studies clearly indicate an increasing risk of serious adverse health outcomes associated with increasing opioid analgesic dose. In particular, the risk of misuse, overdose, and death increases with increasing opioid analgesic dose. However, there is no opioid dose inflection point beyond which the risk of these adverse health outcomes increases. No opioid analgesic dose is without risk.

Conclusions: The reviewed studies show an increasing risk of serious adverse health outcomes-including misuse, overdose, and death-associated with increasing opioid analgesic dose. Further research is needed to characterize the relationship between opioid analgesic dose and the risk of addiction and abuse. This analysis could inform policy actions for regulators and clinical decision making for providers.