The number of drug overdose deaths per year rose 23% between 2010 and 2014, to 47,055, according to a recent report by the Centers for Disease Control and Prevention. The 10 most frequently involved drugs included six opioids (heroin, oxycodone, methadone, morphine, hydrocodone and fentanyl); two benzodiazepines (alprazolam and diazepam); and two stimulants (cocaine and methamphetamine). The rate of drug overdose deaths involving heroin more than tripled over the five-year period, while the rate involving methamphetamine more than doubled.