Poisoning is now the second leading cause of unintentional injury death in the U.S. While several recent high-profile Hollywood celebrity cases have brought the problem to public attention, the rates of unintentional poisoning deaths have been on the rise for more than 15 years, and in fact, unintentional poisoning has surpassed motor vehicle crashes as the leading cause of unintentional injury death among people 35-54 years of age. In a study published in the May issue of the American Journal of Preventive Medicine, researchers found that hospitalizations for poisoning by prescription opioids, sedatives and tranquilizers in the U.S. have increased by 65% from 1999 to 2006.

"Deaths and hospitalizations associated with prescription drug misuse have reached epidemic proportions," said the study's lead author, Jeffrey H. Coben, MD, of the West Virginia University School of Medicine. "It is essential that health care providers, pharmacists, insurance providers, state and federal agencies, and the general public all work together to address this crisis. Prescription medications are just as powerful and dangerous as other notorious street drugs, and we need to ensure people are aware of these dangers and that treatment services are available for those with substance abuse problems."

In the first comprehensive examination of nationwide hospitalizations associated with these prescription medications, researchers examined data gathered from the Nationwide Inpatient Sample (NIS), which contains records for approximately 8 million hospitalizations per year. By using standard diagnosis codes from the ICD-9-CM, the authors extracted from the NIS all poisonings by drugs, medicinal, and biological substances reported from 1999-2006, and further categorized the specific types of drugs in each case. It was also possible to determine whether the poisoning was diagnosed as intentional, unintentional or undetermined.

Dr. Coben believes that while the data reveals a fast-growing problem, there's an urgent need for more in-depth research on this wave of injuries and deaths. Writing in the article, he said, "Interviews with survivors could provide important additional details regarding the pathways to abuse of these drugs, the methods used to obtain the medications, the sequencing and combination of drugs that result in overdose, and the immediate precursors to these serious events. The association between hospitalization for prescription opioids, sedatives, and tranquilizers and subsequent morbidity and mortality is another area in need of further research."

While the majority of hospitalized poisonings are classified as unintentional, substantial increases were also demonstrated for intentional overdoses associated with these drugs, likely reflecting their widespread availability in community settings.

From 1999-2006, total estimated hospitalizations in the U.S. for poisoning by prescription opioids, sedatives, and tranquilizers increased by 65%; while unintentional poisonings by these drugs increased by 37%. In comparison, during this same period, hospitalizations for poisoning by other drugs, medicinal and biological substances increased by 33%, while all other hospitalizations increased by just over 11%. Unintentional poisonings by other substances increased by 21%. Intentional poisonings from prescription opioids, sedatives, and tranquilizers rose by a total of 130% compared to a 53% increase in intentional poisonings from other substances.

The largest percentage increase in hospitalizations for poisoning for a specific drug was observed for methadone (400%). Poisonings by benzodiazepines increased 39%. Hospitalizations for poisoning by barbiturates actually decreased 41%, as did hospitalizations for poisoning by antidepressants (a decrease of 13%).