http://www.cdc.gov/HomeandRecreationalSafety/pdf/poison-issue-brief.pdf
Drug poisoning sounds the same as overdose. Accidental or intentional:
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A poisoning occurs when a persons 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.