The 16 ingested cocaine laced with atropine, a poisonous alkaloid that can lead to convulsions, unconsciousness and death, ANSA reported.
The 16 victims, ages 20 to 40, were reported to be out of danger. They all live in Seriate, near Bergamo.
The Italian government recently reported a sharp rise in the use of cocaine, with Interior Minister Giulio Amato calling demand for the drug "gigantic."
In Europe, cocaine consumption is believed to be higher only in Britain and Spain. Government figures from 2005 show 7 percent of Italians between the ages of 14 and 54 admitted to trying cocaine at least once, suggesting an 80 percent rise in cocaine use between 1995 and 2005.
Cocaine was found floating in the air of Rome in May, said a government pollution report.