Periodicity of presentations of drugs of abuse and overdose in an emergency department.

In order to determine whether temporal factors impact on drugs of abuse and overdose presentations to an urban emergency department, we studied the records of 630 consecutive drug overdose presentations over a period from October 1987 to March 1990. Particular note was made of the time of day of presentation along with the nature of the drug(s) ingested. A significant curve (p less than 0.0005) was obtained for a 24 h period with a peak time of presentation being 6:32 pm (95% confidence interval of 1 h 54 min). Significant periodic rhythms were noted for cocaine, opiates, alcohol, analgesics, marijuana, and benzodiazepines. A 4.8 h periodic rhythm was demonstrated for cocaine, marijuana and alcohol-in-combination. We conclude that the emergency department should be most prepared to treat the drug overdose patient in the early evening and emergency department staffing should reflect this peak in demand.