Toxicity occurs when too much of a drug accumulates in the bloodstream due to overdose or the inability of the kidneys or liver to break down the drug. The degree of harmful effects varies depending on the drug and dose but can be life-threatening. Acetaminophen toxicity specifically damages the liver between 72-96 hours after ingestion, causing hepatic necrosis and dysfunction which can lead to multi-organ failure if left untreated. It is important to always take drugs as directed and not exceed dosages in order to prevent toxicity, as acetaminophen is found in over 600 medications making it easy to inadvertently take too much.