A poisoning occurs when a person’s exposure to a natural or manmade substance has an
undesirable effect. A drug poisoning occurs when that substance is an illegal, prescription, or
over-the-counter drug. Most fatal poisonings in the United States result from drug poisoning.
Poisoning can be classified as:
• self-harm or suicide when the person wants to harm himself;
• assault or homicide when the person wants to harm another; and
• unintentional, also known as “accidental,” when no harm is intended. Unintentional drug
poisoning includes drug overdoses resulting from drug misuse, drug abuse, and taking too
much of a drug for medical reasons.
This document summarizes the most recent information about deaths and emergency
department (ED) visits resulting from drug poisoning. Information about deaths comes from
death certificates for deaths in 2007. Information about emergency department visits comes
from a national surveillance system, the Drug Abuse Warning Network (DAWN), operated by
the Substance Abuse and Mental Health Services Administration (SAMHSA).