Drug-induced deaths include all deaths for which drugs are the underlying cause, including those attributable to acute poisoning by drugs (drug overdoses) and deaths from medical conditions resulting from chronic drug use (e.g., drug-induced Cushing's syndrome). A drug includes illicit or street drugs (e.g., heroin and cocaine), as well as legal prescription and over-the-counter drugs; alcohol is not included. Deaths from drug overdose have increased sharply in the past decade. This increase has been associated with overdoses of prescription opioid pain relievers, which have more than tripled in the past 20 years, escalating to 16,651 deaths in the United States in 2010. Most drug-induced deaths are unintentional drug poisoning deaths, with suicidal drug poisoning and drug poisoning of undetermined intent comprising the majority of the remainder.