Acute and chronic drug abuse emergencies in Metropolitan Toronto.

From 3,548 drug overdose or abuse cases presenting at 21 Metropolitan Toronto hospitals' Emergency departments, data concerning demographic and medical characteristics, investigative and management procedures, drug analysis services, and disposition of patients were collected. Of the 3,548 cases, 2,723 (77%) were acute overdose and 816 (23%) were drug abuse. Drug overdose was more common than drug abuse for both sexes, but was more characteristic of females. The drugs most frequently alleged ingested were benzodiazepines (34%), ethanol (32%), salicylates (16%), and barbiturates (14%). The frequency with which particular classes of drugs are alleged in overdose corresponds closely to the frequency of prescribing these drugs in Ontario.