Hospitalizations for poisoning by prescription opioids, sedatives, and tranquilizers

Background: Unintentional poisoning deaths have been increasing dramatically over the past decade, and the majority of this increase has resulted from overdoses of specific prescription drugs. Despite this trend, there are limited existing data examining hospitalizations for poisonings, both unintentional and intentional, associated with prescription drugs. A better understanding of these hospitalizations may help identify high-risk populations in need of intervention to prevent subsequent mortality.

Purpose: This article aims to describe the incidence and characteristics of hospitalizations resulting from poisoning by prescription opioids, sedatives, and tranquilizers in the U.S. from 1999 to 2006 and make comparisons to hospitalizations for all other poisonings during this time period.

Methods: Hospitalizations for poisonings were selected from the Nationwide Inpatient Sample (NIS), a stratified, representative sample of approximately 8 million hospitalizations each year, according to the principal discharge diagnosis. Intentionality of the poisoning was determined by external cause of injury codes. SAS callable SUDAAN software was used to calculate weighted estimates of poisoning hospitalizations by type and intentionality. Demographic and clinical characteristics of poisoning cohorts were compared. Data were analyzed in 2009.

Results: From 1999 to 2006, U.S. hospitalizations for poisoning by prescription opioids, sedatives, and tranquilizers increased a total of 65%. This increase was double the increase observed in hospitalizations for poisoning by other drugs and substances. The largest increase in the number of hospitalized cases over the 7-year period was seen for poisonings by benzodiazepines, whereas the largest percentage increase was observed for methadone (400%). In comparison to patients hospitalized for poisoning from other substances, those hospitalized for prescription opioids, sedatives, and tranquilizers were more likely to be women, aged >34 years, and to present to a rural or urban nonteaching hospital.

Conclusions: Prescription opioids, sedatives, and tranquilizers are an increasing cause of hospitalization. The hospital admission provides an opportunity to better understand the contextual factors contributing to these cases, which may aid in the development of targeted prevention strategies.