According to the Centers for Disease Control and Prevention (CDC), poisons include substances, such as medications, that could harm the body if ingested, inhaled, injected or absorbed through the skin in extremely large quantities (1). Poisonings could be intentional or unintentional, and could happen if an individual is exposed to either a natural or man-made substance that results in an undesirable effect (2). The incidence of unintentional poisoning usually involves the non-chemical use of drugs or chemicals in amounts that are excessive - such as an "overdose" - and this use could be non-recreational as well, especially involving toddlers (1). Among deaths attributed to drugs, the more common drugs involved are cocaine, heroin, and a prescription drug known as opioid painkillers (2).

For the year 2010, there were about 2.4 million calls to poison control centers about human poison exposure cases (1), and the Drug Abuse Warning Network (DAWN) findings for the year 2010 revealed that about 4.9 million drug-related emergency department (ED) visits were made concerning drug poisoning/overdose (3). Of the 41,592 poisoning deaths in the United States for the year 2009, it was found that 31,758 (76 percent) were unintentional (1), and unintentional poisoning deaths for the year 2009 were predominantly cause by drugs, about 28, 754 (91 percent) deaths (1).

It has been reported that in 2010, painkillers were prescribed so often that there was enough in circulation to medicate every adult in America around the clock for a month (4). These pills were prescribed for medical reasons but many were found to have ended up in the possession of people who used them for non-medical purposes, thus misusing or abusing them.