Pharmaceutical Overdose Deaths, United States, 2010

To the Editor: Data recently released by the National Center for Health Statistics show drug overdose deaths increased for the 11th consecutive year in 2010.¹ Pharmaceuticals, especially opioid analgesics, have driven this increase.² Other pharmaceuticals are involved in opioid overdose deaths, but their involvement is less well characterized. Using 2010 mortality data, we describe the specific drugs involved in pharmaceutical and opioid-related overdose deaths.

Data are from the National Vital Statistics System multiple cause-of-death file, which is based on death certificates submitted by medical examiners or coroners.¹ Drug overdose deaths were those assigned an underlying cause of death using the International Classification of Diseases, Tenth Revision (ICD-10) codes X40-X44 (unintentional), X60-X64 (suicide), X85 (homicide), and Y10-Y14 (undetermined intent). Pharmaceutical-related overdose deaths were those assigned specific ICD-10 codes T36-T39, T40.2-T40.4, T41-T43.5, and T43.8-T50.8; psychotherapeutic and central nervous system pharmaceuticals were defined as T40.2-T40.4, T42, T43.0-T43.5, T43.8, T43.9; and opioid analgesics were those assigned codes T40.2-T40.4. Pharmaceutical deaths by this definition are predominately due to prescription drugs; a small minority involve over-the-counter or illicit drugs combined with prescription drugs in the same ICD-10 T codes. Institutional review board approval was waived because no personal identifiers were involved.

In 2010, there were 38 329 drug overdose deaths in the United States; most (22 134; 57.7%) involved pharmaceuticals; 9429 (24.6%) involved only unspecified drugs. Of the pharmaceutical-related overdose deaths, 16 451 (74.3%) were unintentional, 3780 (17.1%) were suicides, and 1868 (8.4%) were of undetermined intent. Opioids (16 651; 75.2%), benzodiazepines (6497; 29.4%), antidepressants (3889; 17.6%), and antiepileptic and antiparkinsonism drugs (1717; 7.8%) were the pharmaceuticals (alone or in combination with other drugs) most commonly involved in pharmaceutical overdose deaths (Table). Among overdose deaths involving opioid analgesics, the pharmaceuticals most often also involved in these deaths were benzodiazepines (5017; 30.1%), antidepressants (2239; 13.4%), antiepileptic and antiparkinsonism drugs (1125; 6.8%), and antipsychotics and neuroleptics (783; 4.7%).

Opioids were frequently implicated in overdose deaths involving other pharmaceuticals. They were involved in the majority of deaths involving benzodiazepines (77.2%), antiepileptic and antiparkinsonism drugs (65.5%), antipsychotic and neuroleptic drugs (58.0%), antidepressants (57.6%), other analgesics, antipyretics, and antirheumatics (56.5%), and other psychotropic drugs (54.2%). Among overdose deaths due to psychotherapeutic and central nervous system pharmaceuticals, the proportion involving only a single class of such drugs was highest for opioids (4903/16 651; 29.4%) and lowest for benzodiazepines (239/6497; 3.7%) (Figure).

Death certificate data have limitations,³ but they are the sole source for detailed death information at the national level. This analysis is limited by the 25% of death certificates in which the type of drugs involved was not specified, an omission due to lack of toxicological testing or failure to record the results of such tests on the death certificate. Therefore, the numbers reported in this analysis are undercounts. Additionally, the degree to which drugs are specified on death certificates might vary across the United States and therefore differentially undercount types of drugs more common in areas in which death certificates are less complete. This might affect the ranking of some pharmaceuticals in the Table.

This analysis confirms the predominant role opioid analgesics play in pharmaceutical overdose deaths, either alone or in combination with other drugs. It also, however, highlights the frequent involvement of drugs typically prescribed for mental health conditions such as benzodiazepines, antidepressants, and antipsychotics in overdose deaths. People with mental health disorders are at increased risk for heavy therapeutic use, nonmedical use, and overdose of opioids.^4-6 Screening, identification, and appropriate management of such disorders is an important part of both behavioral health and chronic pain management. Tools such as prescription drug monitoring programs and electronic health records can help clinicians to identify risky medication use and inform treatment decisions, especially for opioids and benzodiazepines.

Author Contributions: Dr Jones had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Study concept and design: Jones, Paulozzi.

Acquisition of data: Jones.

Analysis and interpretation of data: Jones, Mack, Paulozzi.

Drafting of the manuscript: Jones.

Critical revision of the manuscript for important intellectual content: Jones, Mack, Paulozzi.

Statistical analysis: Jones.

Administrative, technical, or material support: Mack, Paulozzi.

Study supervision: Jones.

Funding/Support: The US Centers for Disease Control and Prevention funded this study.

Role of the Sponsor: The US Centers for Disease Control and Prevention supported the staff responsible for the design and conduct of the study; in the collection, analysis, and interpretation of the data; or in the preparation, review, or approval of the manuscript.

Disclaimer: The views expressed in this article are those of the authors and do not necessarily reflect the official position of the US Centers for Disease Control and Prevention.