Phencyclidine also known as angel dust, is a dissociative drug formerly used as an anesthetic agent, exhibiting hallucinogenic and neurotoxic effects. It was first patented in 1952 by the Parke-Davis pharmaceutical company and marketed under the brand name Sernyl. PCP is listed as a Schedule II drug in the United States under the Convention on Psychotropic Substances. Although the primary psychoactive effects of the drug last only hours, total elimination from the body is prolonged, typically extending over at least 8 days. Street names for PCP include: angel dust, ozone, wack, rocket fuel, and many others. Many PCP users are brought to emergency rooms because of overdose or because of the drug's unpleasant psychological effects. In a hospital or detention setting, people high on PCP often become violent or suicidal.