Phencyclidine An Update Editor Doris H. Clouet

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Balster, R.L., and Pross, R.S. Phencyclidine: A bibliography of biomedical and behavioral research. J Psyched Drugs 1O:1-15, 1978.

Balster, R.L., and Wessinger, W.D. Central nervous system depressant effects of phencyclidine. In: Kamenka. J.M.; Domino. E.F.; and Geneste. P., eds. Phencyclidine and Related Arylcyclohexylamines: Present and Future Applications. Ann Arbor: NPP Books. 1983. pp. 291-309.

Balster, R.L., and Woolverton, W.L. Continuous access phencyclidine self-administration by rhesus monkeys leading to physical dependence. Psychopharmacology (Berlin) 70:5-10, 1980.

Balster, R.L., and Woolverton, W.L. Tolerance and dependence to phencyclidine. In: Domino, E.F., ed. PCP (Phencyclidine): Historical and Current Perspectives. Ann Arbor: NPP Books, 1981. pp. 293-306.

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Balster, R.L.; Johanson, C.E.; Harris, R.T.; and Schuster, C.R. Phencyclidine self-administration in the rhesus monkey.

Pharmacol Biochem Behav 1:167-172, 1973.
Brady, K.T., and Balster, R.L. Discriminative stimulus		properties
of phencyclidine and five analogues in the squirrel monkey.
Pharmacol Biochem Behav 14:213-218, 1981.
Brady, K.T.; Balster, R.L.; and May, E.L. Stereoisomers		of N-
allylnormetazocine:	Phencyclidine-like behavioral effects-in

squirrel monkeys and rats." Science 212:178-180, 1982a.

Brady, K.T.; Bolster, R.L.; Meltzer, L.T.; and Schwertz, D. Comparison of phencyclidine and three analogues on fixed-interval performance in rhesus monkeys. Pharmacol Biochem Behav 12:67-

71,	1980.
Brady, K.T.; Balster, R.L.; and Woolverton, W.L. Discriminative
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in monkeys. J Pharmacol Exp Ther 220:56-62, 1982b.
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Chait, L.D., and Balster, R.L.			Interaction	between	phencyclidine
and	pentobarbital in several		species of	laboratory animals.

Comm Psychopharmacol 2:351-356, 1978.

Chait, L.D.; Wenger, G.R.; and McMillan, D.E. Effects of phencyclidine and ketamine on punished and unpunished responding in pigeons. Pharmacol Biochem Behav 15:145-148, 1981.

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Domino, E.F., and Luby, E.D. Abnormal mental states induced by phencyclidine as a model of schizophrenia. In: Domino, E.F., ed. PCP (Phencyclidine): Historical and Current Perspectives. Ann Arbor: NPP Books, 1981. pp. 4O1-418.

Eastman, J.W., and Cohen, S.N. Hypertensive crisis and death associated with phencyclidine poisoning. JAMA 231:1270-1271, 1975.

Freeman, A.S.; Martin, B.R.; and Balster, R.L. Relationship between the development of behavioral tolerance and the biodisposition of phencyclidine in mice. Pharmacol Biochem Behav 20:373-377, 1984.

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Hayes, B.H., and Balster, R.L. Anticonvulsant effects of phen- cyclidine-like drugs in mice. Fed Proc 44:724, 1985.

Holtzman, S.G. Phencyclidine-like discriminative effects of opioids in the rat. J Pharmaco1 Exp Ther 214:614-619, 1980.

Johnson, K.M. Phencyclidine: Behavioral and biochemical evidence supporting a role for dopamine. Fed Proc 42:2579-2583, 1983.

Johnson, K.M., and Balster, R.L. Acute chronic phencyclidine administration: Relationship between biodispositional factors and behavioral effects. Subst Alcohol Actions Misuse 2:131-142, 1981.

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Kanner, M.; Finnegan, K.; and Meltzer, H.Y. Dopaminergic effects of phencyclidine in rats with nigrostriatal lesions. Psychopharmacol Comm 1:393-401, 1975.

Landauer, M.L., and Balster, R.L. The effects of aggregation on the lethality of phencyclidine in mice. Toxicol Lett, 12:171176, 1982.

Landauer, M.L.; Woolverton, W.L.; and Balster, R.L. The effects of chlorpromazine on the lethality of d-amphetamine and phencyclidine in mice. Res Comm Subst Abuse 3:287-295, 1982.

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Lukas, S.E.; Griffiths, R.R.; Brady, J.V.; and Wurster, R.M. Phencyclidine-analogue self-injection by the baboon. Psychopharmacology (Berlin) 83:316-320, 1984.

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ACKNOWLEDGEMENTS

My colleagues whose names appear as my co-authors on the papers cited for this report are due a substantial portion of the credit for most of the research described herein. The research has been supported by National Institute on Drug Abuse Grant DA-01442.

AUTHOR

Robert L. Balster, Ph.D.

Department of Pharmacology and Toxicology

Medical College of Virginia

Virginia Commonwealth University

Richmond, VA 23298

162

Phencyclidine: Changing

Abuse Patterns

Raquel Crider

GENERAL TRENDS 1973 TO 1984

Phencyclidine (PCP), one of the arylcyclohexylamines. was developed and originally used as a general anesthetic for humans. Due to psychotic and hallucinogenic reactions, use of the drug for humans was discontinued. It is now used legally only in veterinary medicine as an animal immobilizing agent.

Currently, trends in PCP abuse are monitored through emergency room visits, deaths, initiates entering drug abuse treatment programs, and surveys, as shown in table 1 and figures 1 and 2. The years between 1973 and 1984 have been divided into three periods: during the years between 1973 and 1978/1979, the indicators of PCP

use increased; the period 1978/1979 through	1981	marked		a	decline
in the PCP indicators; 1981 to the present	time	are	years		in	which
PCP indicators have shown resurgence.
Indicators of PCP abuse, i.e., emergencies,	deaths,		and	the		number

of initiates entering treatment, increased between 1973 and 1978/ 1979. Between 1973 and 1975, the rate of initiates, based on treatment year-of-first-use records, increased more rapidly than the number of emergencies. This phenomenon may be explained, in part, by a change in the route of administration. Beginning about 1972, PCP users changed from administering the drug orally in tablet or capsule form to smoking the drug on leaf material, such as

marijuana,		tobacco, or	parsley. By smoking,	PCP users	were	able
to	control	the dosage	more effectively, thus	decreasing	the	chance
of	overdose.

By 1978/1979, indicators of PCP abuse leveled off and started to decline. This trend is thought to be related to a variety of activities initiated by health and law enforcement officials, including a nationwide education campaign in which 18,000 letters

163

were mailed to treatment programs, emergency rooms, health agencies, and medical examiner/coroner offices describing the typical reactions to PCP, and treatment procedures. In addition, PCP was rescheduled from Schedule III to Schedule II of the Controlled Substance Act, a highly restrictive category reserved for substances with limited legitimate use and/or significant abuse potential. The PCP analogues, PCE, PHP, and TCP were placed in Schedule I. Required reporting of production of the precursor, piperidine, began in 1979. Penalties for possession of PCP with intent to sell were increased at about the same time. As a result of these and other efforts, the number of emergencies, deaths, and PCP initiates entering treatment began to decline.

TABLE	1.	PCP indicators
					Number	Percent	Percent
		PCP Emergencies		PCP	“Ever Use”	30-Day Use	Age	12-17
PCP Related				Initiate	in	In High	"Ever	Use"
Deaths		National2	In Panel3	Treated4	Households5	School	Households7
1973		1.400		3.42
1974		1.934		4.24
1975		1.768		5.49
1976		2.799		6.32			3.0
1977	8.1	4.993		7.16	6.98		5.8
1970	12.3	9.877		9.13
1979	10.5	10.288		5.67	7.01	2.4	3.9
1980	8.5	7.154	3.781	2.88		1.4
1981	9.4	5.840	2.722	1.27		1.4
1982	16.4	8.067	3.383		8.28	1.0	2.2
1983	23.8	9.782	4.376			1.3
1984	21.7		4.526			1.0

1. Number of PCP related deaths x 10-1 reported to DAWN. Newark and New York exeluded after 1981. The 1984 data are preliminary (National lnstitute on Drug Abuse 1985c).

2.Number of PCP related emergencies x 10-3 reported to DAWN projected to the Nation (Hinkley and Greenwood 1982).

3. Number of imputed PCP related emergencies x 10-3 reported to a consistent panel of hospitals In DAWN (National lnstitute on Drug Abuse 1985a).

4.Number of PCP lnitiates x 10-2 starting use 1973-1983 admitted to a consistent panel of 402 treatment programs In 1977 through 1981.

5.Number of persons in households x 10-6 having ever used PCP 1970, 1979, and 1982 (Miller et al. 1983).

6.Percent of high school seniors using PCP In the 30 days prior to the survey (Johnston et al. 1985).

7.Percent ages 12 to 17 years In households reporting ever having used PCP (Miller et al. 1983).

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KEY:	=	PCP	ralated	mortalities (NY	and	Newark	excluded) x 10-1;	= P C P
emergencies		projected to		nation x 10-3;	=	PCP	emergencies reported	to con-
sistent	panel		x 10-3.

FIGURE 1. The number of PCP-retated emergencies projected to the Nation, and the number of PCP-related deaths, peaked in 1978/1979, declined through 1980/1981, then increased in 1981 through 1984

By 1981, some of the indicators of PCP abuse began to increase again. The number of PCP-related emergencies projected to the Nation from the Drug Abuse Warning Network (DAWN) data showed an increase from 5,840 in 1981 to 9,782 in 1983 (Hinkley and Greenwood 1984). Data from a consistent panel of reporting hospitals indicate that the number of emergencies continued to increase through 1983. The number of PCP-related deaths reported to DAWN increased from 96 in 1981, to 154 in 1983 (National Institute on Drug Abuse 1984). The estimated number of persons reporting ever having used PCP increased from 7.01 million in 1979 to 8.28 million in 1982 (Miller et al. 1983).

The recent increase, however, appears to be concentrated primarily in the metropolitan areas of Los Angeles, Washington, D.C., and New York City. These three areas accounted for 76.0 percent of the emergencies reported to DAWN in 1983, while Los Angeles and Washington, D.C. accounted for 81.8 percent of the PCP-related deaths2. Rates of PCP emergencies per 100,000 total emergencies are available for 26 major metropolitan areas in 1983, based on DAWN data (National Institute on Drug Abuse 1985d). The areas of Los Angeles, Washington, D.C., and New York City show the highest rates at 2.52, 2.03 and 0.53 per 100,000 emergencies, respectively, in 1984.

165

KEY:

= Percent of

household

residents

ages 12

to 17

years

reporting

"ever

use”

of PCP;

=

Percent

of

high school seniors

using

PCP In past 30 days;

=

PCP

lnitiates

In

treatment

x 10-2,

corrected

for

lag

between

first

use and

treatment.

FIGURE 2. The increase in PCP indicators starting in 1981 does not reflect an increase for new or young users. The number of PCP initiates first admitted to treatment, the percent of high school seniors using the drug in the 30 days prior to the survey, and the percent of persons ages 12 to 17 years in households reporting ever having used PCP declined in the late 1970s and remained at low levels since the early 1980s.

Table 2 shows the number of PCP-related emergencies for the period of 1982 to 1984 by quarter for New York, Los Angeles, and Washington, D.C. For New York and Washington, D.C., the average number of mentions increased significantly between 1983 and 1984.

The decline in Los Angeles between 1983 and 1984 cannot immediately be interpreted as a decline in PCP use for that city. In 1981, during an investigation of PCP trends in Los Angeles, it was discovered that many PCP emergencies were diverted to psychiatric units, better equipped to handle the violent behavior sometimes accompanying PCP reactions. These psychiatric units were not participating in the DAWN network at that time (Kozel and Husson 1981). It is possible that similar systemic problems may have occurred in 1984.

166

TABLE 2. Number of PCP-related emergencies from a consistent panel of emergency rooms in New York, Washington, D.C., and Los Angeles, 1982-1984

Time	Frame	New York	Washington, D.C.	Los Angeles
1982	Q1	93	49	567
	Q2	147	68	660
	Q3	147	68	660
	Q4	125	96	589
1983	Q1	142	104	568
	Q2	173	97	807
	Q3	214	130	910
	Q4	303	179	910
1984	Q1	267	190	641
	Q2	217	285	635
	Q3	237	285	635
	Q4	239	229	493
Mean	1982	121.6	70.0	600.6
Mean	1983	207.9	127.6	751.8
Mean	1984	240.0	241.4	621.0

SOURCE: National institute on Drug Abuse 1985b.

Potential problems in PCP abuse were also reported in New Orleans and St. Louis (National Institute on Drug Abuse, in preparation), although the quarterly frequencies of emergency room mentions in

those		SMSAs	were small compared to New York, Washington, D.C., and
Los	Angeles.
NEW	OR	YOUNG	USERS

Based on data from national surveillance systems, the increase between 1981 and 1983 does not appear to reflect substantial increased use among new or young users, as occurred during the early and mid-1970s, although there may be regional variations. In general, the number of initiates declined sharply after 1977 and remained at low levels through 1981. Table 1 and figure 2 show

that	there were 913 initiates starting use in 1978, first treated
in a	panel of 402 consistently reporting treatment programs. The

167