86: Phencyclidine and Ketamine

HISTORY AND EPIDEMIOLOGY

Phencyclidine (PCP) was discovered in 1926 but was not developed as a general anesthetic until the 1950s. At that time, the Parke Davis drug company was searching for an ideal intravenous (IV) anesthetic to rapidly achieve analgesia and anesthesia with minimal cardiovascular and respiratory depression.³⁷ PCP was marketed under the name Sernyl because it rendered an apparent state of serenity when administered to laboratory monkeys. Its surgical use began in 1963, but was rapidly discontinued when a 10% to 30% incidence of postoperative psychoses and dysphoria was documented over the subsequent 2-year period.⁸⁶ By 1967 the use of PCP was limited exclusively to veterinary medicine as a tranquilizer marketed under the name Sernylan.

Simultaneously, in the 1960s, PCP emerged as a street drug in San Francisco called “the PeaCe Pill.”⁷⁰ Numerous street names have been given to phencyclidine; on the West Coast, it was called “angel dust,” PCP, “crystal,” and “crystal joints” (CJs); in Chicago it was called “THC” or “TAC”; and those on the East Coast opted for “the sheets,” “Hog,” or “elephant tranquilizer.”¹³² Ironically, PCP was initially unpopular with drug users because of its dysphoric effects and unpredictable oral absorption.¹⁷³ However, with time its use spread in a similar geographic pattern to that of marijuana and lysergic acid diethylamide (LSD), from the coastal United States to the Midwest region.⁷⁰

PCP abuse became widespread during the 1970s.^26,200 The relatively easy and inexpensive synthesis coupled with the common marketing of PCP as LSD, mescaline, psilocybin, cocaine, amphetamine, and/or “synthetic THC” (tetrahydrocannabinol) added to its allure and consumption.¹³² By the late 1970s PCP abuse had reached epidemic proportions.⁸ The Drug Abuse Warning Network (DAWN) reported that the number of PCP-related emergencies and deaths had more than doubled from 1975 to 1977. In 1978 the National Institute of Drug Abuse reported that 13.9% of young adults (18–25 years old) had used PCP.⁵³ The manufacture of PCP was ultimately prohibited in 1978 when it was added to the list of federally controlled substances. Classifying PCP as a Schedule II drug led to its decrease in availability and, consequently, a decrease in its use. Although the 1980s brought about a cocaine epidemic that eclipsed PCP, PCP has remained consistently available, primarily regionalized to large cities in the northeastern United States and in the Los Angeles area,¹¹¹ where PCP use continues to rise and fall with societal trends. Because many of the PCP congeners made during the manufacturing process were being abused in place of PCP, the Controlled Substance Act of 1986 made these derivatives illegal and established that the use of the precursor of PCP, piperidine, necessitated mandatory reporting. With this new law in place, those possessing similar but not identical illegal substances could be prosecuted. This led to a further decline in the popularity of PCP. Beginning in 1984, the ...