Deaths involving the opioid painkiller fentanyl more than doubled from 2013 to 2014, according to a report released on December 20 by the Centers for Disease Control and Prevention's National Center for Health Statistics (NCHS).

The report provides a detailed picture of the drugs most frequently involved in drug overdose deaths in the United States and highlights the frequency of deaths involving multiple drugs.

From 2010 through 2014, the number of deaths from drug overdose increased by 23%, from 38,329 in 2010 to 47,055 in 2014, report NCHS author Margaret Warner, PhD, and colleagues.

As determined on the basis of death certificate data, the drugs most often involved in overdose deaths were the opioids heroin, oxycodone, methadone, morphine, hydrocodone, and fentanyl; the benzodiazepines alprazolam and diazepam; and the stimulants cocaine and methamphetamine.

Among other key findings in the report:

Oxycodone ranked first in 2010 and 2011 among drug overdose deaths. Heroin ranked first from 2012 through 2014.

The number of drug overdose deaths that involved heroin more than tripled, from 3020 deaths, or 8% of all drug overdose deaths in 2010, to 10,863 deaths, or 23% of all drug overdose deaths in 2014.

Each year, cocaine ranked second or third among drugs involved in drug overdose deaths.

From 2010 through 2012, fentanyl was involved in roughly 1600 drug overdose deaths each year. Fentanyl involvement increased to 1905 deaths in 2013 and to 4200 deaths in 2014.

Only methadone showed a decreasing drug overdose death rate, from 1.5 per 100,000 population in 2011 to 1.1 in 2014. The number of drug overdose deaths involving methadone fell from 4408 in 2010 to 3495 in 2014.

The number of drug overdose deaths that involved methamphetamine increased from 1388 in 2010 to 3728 in 2014.

The authors note that the frequency with which death certificates cited specific drugs improved during the 5-year study period.

In 2010, 67% of drug overdose deaths included mention of specific drugs, compared with 78% in 2014. From death certificates that cited only a drug class, more than two thirds of deaths involved either opioids or opiates. Of the deaths in which death certificates made no mention of involvement of a specific drug or drug class, nearly half gave some indication that the deaths involved multiple drugs, with mention of "polypharmacy" or "multidrug."

The data are based on a new method developed by the NCHS and the FDA's Center for Drug Evaluation and Research in which the literal text from the death certificates was analyzed to identify specific drugs involved in overdose deaths. The method was applied to "provide a more in-depth understanding of the national picture of the drugs involved in drug overdose deaths," the authors say.

National Vital Statistics Reports. 2016;65. Published online December 20, 2016. Full text