Drugs Most Frequently Involved in Drug Overdose Deaths: United States, 2010-2014.

Objectives-This report identifies the specific drugs most frequently involved in drug overdose deaths in the United States from 2010 through 2014. Methods-The 2010-2014 National Vital Statistics System mortality files were linked to electronic files containing literal text information from death certificates. Drug overdose was defined using the International Classification of Diseases, Tenth Revision underlying cause-of-death codes X40-X44 (unintentional), X60-X64 (suicide), X85 (homicide), and Y10-Y14 (undetermined intent). Among deaths with an underlying cause of death of drug overdose, the literal text in three fields of the death certificate (i.e., the cause of death from Part I, significant conditions contributing to death from Part II, and a description of how the injury occurred from Box 43) were searched to identify drug mentions. Search term lists were developed using existing drug classification systems as well as from manual review of the literal text. The search term list was then used to identify the specific drugs involved in overdose deaths. Descriptive statistics were reported for drug overdose deaths involving the 10 most frequently mentioned drugs on death certificates. Tables and figures presenting information on the specific drugs involved in deaths are based on deaths with mention of at least one specific drug on the death certificate. Results-From 2010 through 2014, the number of drug overdose deaths per year increased 23%, from 38,329 in 2010 to 47,055 in 2014. During this time period, the percentage of drug overdose deaths involving at least one specific drug increased, from 67% in 2010 to 78% in 2014. Among drug overdose deaths with at least one drug specified on the death certificate, the 10 drugs most frequently involved in overdose deaths included the following opioids: heroin, oxycodone, methadone, morphine, hydrocodone, and fentanyl; the following benzodiazepines: alprazolam and diazepam; and the following stimulants: cocaine and methamphetamine. During this 5-year period, the age-adjusted rate of drug overdose deaths involving heroin more than tripled, and the rate of drug overdose deaths involving methamphetamine more than doubled. The rate of drug overdose deaths involving fentanyl more than doubled in a single year (from 2013 to 2014). In 2014, of the 36,667 drug overdose deaths involving at least one specific drug, 52% of these deaths specified one drug, 38% specified two or three drugs, and 11% specified four or more drugs. Conclusions-Analysis of the literal text from death certificates can be used to identify patterns in the specific drugs most frequently involved in drug overdose deaths. From 2010 through 2014, the top 10 drugs involved were the same, but the relative ranking and age-adjusted rates for deaths involving these drugs changed. Literal text analysis also revealed that many drug overdose deaths involved multiple drugs. Findings should be interpreted in light of the improvement in the quality of the data that resulted from better reporting of specific drugs on death certificates from 2010 through 2014. Relative increases in the death rates involving specific drugs and the rankings of these drugs may be affected by improvements in reporting, real increases in the numbers of death, or both.