Chloroquine psychosis masquerading as PCP: a case report.

Chloroquine and its derivatives have been drugs of choice in the prophylaxis and treatment of malaria for over 50 years. These drugs are also frequently used in the treatment of various rheumatologic disorders. Because many Americans now travel abroad and may require chloroquine prophylaxis, as well as the fact that such medications are readily available through Internet-based supply houses, clinicians should be aware of the potential toxicity associated with the use of these agents. We present the case of an adolescent female who presented with acute, chloroquine-induced toxic psychosis resembling that induced by phencyclidine (PCP) in clinical presentation and laboratory findings. In the acute setting, the differentiation between chloroquine toxic psychosis and PCP psychosis may be difficult. Therefore, the syndrome of chloroquine-induced psychosis is reviewed and its differentiation from PCP psychosis highlighted as it relates to important aspects of this case.

Neuropsychological effects of formaldehyde use.

This study compared five individuals who intentionally ingested formaldehyde (possibly laced with PCP) in marijuana cigarettes to a control group on measures of cognitive ability. Formaldehyde, a major component in embalming fluid, is legal to purchase and possess and has become popular due to its euphoric properties. In significant doses, the chemical is a neurotoxin. The effects of inadvertent exposure are fairly well known, but the effects of intentional ingestion have only recently been investigated. In addition, there has been little research on the effects of formaldehyde use specific to intellectual ability and cognitive intactness. The results of this study indicate intentional ingestion may cause a decline in neuropsychological intactness, as measured by performance on the Shipley Institute of Living Scale.

Long-term effects of developmental PCP administration on sensorimotor gating in male and female rats.

RATIONALE: Acutely administered N-methyl-D-asparate (NMDA) antagonists are used to model schizophrenia, as measured by impairments in sensorimotor gating reflected in decreases in prepulse inhibition of the startle response (PPI). Aspects of acute NMDA receptor antagonism limit the applications of these models. OBJECTIVE: The aim of this paper is to determine the long-term effects of developmental phencyclidine (PCP) treatment on sensorimotor gating in both male and female rats. MATERIALS AND METHODS: Male and female Sprague Dawley rats were injected with PCP (10 mg/kg s.c.) on postnatal days (PN) 7, 9, and 11 and were tested for PPI on PN 32-34. The groups were then divided and some of the animals received a single dose of PCP (10 mg/kg s.c.) on PN 45. The animals were tested again for PPI at approximately 1, 4, and 6 weeks after the treatment. RESULTS: There were no significant effects of neonatal-only treatment. One week after the PN 45 treatment, animals that were treated as neonates and as adolescents (PCP/PCP) were significantly impaired in PPI in both sexes. Male and female PCP/PCP rats also had significant increases in acoustic startle response 4 weeks posttreatment, which subsequently declined. PPI impairments in both sexes recovered over time and the adolescent-only treated females showed significant increases (improvement) in PPI approximately 6 weeks posttreatment. CONCLUSION: These data suggest that treatment with an NMDA receptor antagonist during adolescence or early adulthood can produce a relatively long-term impairment of PPI (approximately 1 week) and that this effect is more pronounced in male animals.

Potential benefit of lamotrigine in managing ketamine use disorder.

Ketamine is an anesthetic derivative of phencyclidine (PCP; 'Angel dust') with dissociative, analgesic and psychedelic properties. Ketamine has become a popular recreational drug of abuse in many parts of the world in recent years. The preclinical studies demonstrate the reinforcing effects of ketamine and long-term ketamine abuse induces a delayed and persistent upregulation of dopamine system. In humans, there have been concerns about its liability to development of addiction. The dilemma of mental professionals in managing the treatment-seeking ketamine abusers comes from a lack of effective pharmacotherapy. Limiting evidence showed that lamotrigine, which inhibits glutamate release, is effective to reduce cocaine craving. We propose that lamotrigine might be beneficial for managing ketamine use disorder clinically. We also reported one case of ketamine use disorder who experienced a great reduction in craving and ketamine use after taking lamotrigine. Although the mechanisms underlying neuroadaptation and reward related to ketamine are not entirely clear, future clinical trials are needed to advance our understanding of the benefit yielded by lamotrigine to treat ketamine use disorder.

Physostigmine and haloperidol treatment of acute phencyclidine intoxication.

Twenty-four patients with phencyclidine intoxication were treated with either physostigmine (2 mg i.m.) or haloperidol (5 mg i.m.) based on the presence of delusions and/or hallucinations. Several symptoms subsequently improved. Schizophreniform symptoms showed substantial improvement with haloperidol.

Chronic phencyclidine abuse and physical assault.

When the authors investigated aggressive behavior on a phencyclidine (PCP) detoxification and rehabilitation unit and compared similar types of behavior on a heroin unit, they found no differences between the two units. The urinary PCP levels of a subgroup of 75 patients admitted to the PCP unit who had PCP-positive urine were significantly higher than those of 75 patients admitted to an acute psychiatric ward because of violent behavior who also had PCP-positive urine. The authors discuss the implications of these findings and the need for more information on the relationship between PCP levels in blood and urine and behavior.

Flashbacks among soldiers discharged as unfit who abused more than one drug.

Of 280 soldiers discharged from military service in 1971 as unfit, 207 reported the heavy use of at least one drug (most of these abused more than one drug) and 146 (52%) reported having flashbacks. Most flashbacks were of a simple visual nature, but repeat "trips," complex subjective experiences, and persistent difficulties in concentration were often reported. The prevalence and severity of flashbacks increased with drug use, particularly with hallucinogens and marijuana. Because psychological, social, and physiological factors may all contribute to flashback phenomena, other populations need to be studied to determine the extent to which these findings can be generalized.

The urban epidemic of phencyclidine (PCP) use: clinical and laboratory evidence from a public psychiatric hospital emergency service.

Routine blood samples of 145 consecutive patients seen in the Los Angeles County Psychiatric Hospital Emergency Room during a 48-hour weekday period in June 1979 were examined for phencyclidine (PCP) using a sensitive and specific gas capillary gas chromatographic nitrogen detector (GC2-N) method. Of these 145 samples 63 (43.4%) were positive and PCP levels ranged 0.34 to 142.9 nanograms/ml (mean 14.6 ng/ml +/- 3.4 S.E.M.). An analysis of the records of these 63 patients revealed a wide variety of psychotic clinical pictures resembling mania, depression or schizophrenia with relatively few of the supposedly characteristic manifestations of PCP intoxication. Each of the 63 patients had at least one manifestation of toxic psychosis and/or acute delirium, in addition to the florid symptoms characteristic of functional states. PCP measurement, pharmacokinetics and the possible relationships of this intoxication to the psychiatric manifestations are discussed.

Improvement of phencyclidine-associated psychosis with ECT.

Phencyclidine-associated psychosis may mimic classic forms of both schizophrenia and affective psychosis. Treatment of phencyclidine-associated psychosis may prove very difficult for some patients. A patient who developed a severe phencyclidine-associated psychosis and failed to respond to high doses of antipsychotics is described. The patient responded dramatically to electroconvulsive therapy.

History of drug abuse and dangerous behavior in inpatient schizophrenics.

The alcohol and drug use histories of 85 schizophrenic inpatients were examined in relation to measures of dangerousness while in hospital (physical and verbal assaults and episodes of seclusion and restraint). Stepwise multiple regression analyses showed significant relationships between each dangerousness measure and certain drug abuse history factors. Assault was most closely related to a drug abuse factor containing a history of blackout episodes and assaultiveness while drinking, whereas seclusion and restraint were most closely related to histories of becoming "loud" while on drugs. Overall measures of dangerousness appear to relate best to histories of becoming loud or assaultive while taking drugs.

Characteristics of 68 chronic phencyclidine abusers who sought treatment.

An analysis of 68 phencyclidine (PCP) users who sought treatment reveals that chronic compulsive, daily use occurs and that intravenous use is relatively common. Twenty-five (37%) subjects considered themselves to be addicted to PCP and 19 (29%) desired medication to assist withdrawal. Unwanted behaviors under the influence of PCP were common and primarily related to memory loss, or acts which resulted from loss of impulse control.

The economic context of drug and non-drug reinforcers affects acquisition and maintenance of drug-reinforced behavior and withdrawal effects.

The focus of this review is to examine the effect of non-drug alternative reinforcers on drug-reinforced behavior. An increasing number of animal laboratory as well as human clinical studies have demonstrated the effectiveness of non-drug reinforcers in reducing steady-state levels of drug self-administration. One goal of this review was to determine what behavioral economic conditions are optimal for reducing drug-reinforced behavior. Variables such as price of the drug and non-drug reinforcer have been manipulated by changing fixed-ratio (FR) value of these commodities. Income has been changed by limiting the amount of access to the commodities or by changing session length. Substitution was evaluated by determining whether decreased demand for a drug (due to increased price) was related to increased demand for a non-drug reinforcer. A second goal of this review was to investigate transition states in the drug addiction process with respect to the role of alternative non-drug reinforcers. Animal models of acquisition and withdrawal were examined to identify behavioral economic conditions under which acquisition may be prevented or withdrawal effects (and potential for relapse) may be alleviated.

Weighing up the pros and cons: help-seeking by drug misusers in Baltimore, USA.

Forty drug misusers receiving treatment in Baltimore completed questionnaires, originally administered to drug misusers in London, about their reasons for seeking help and their worries about the treatment. Seeking help was related to the experiences of addiction, loss of control over life and financial and family difficulties. The main fears were of failing treatment. These responses are similar to those obtained in the London group. There was little correlation between objective assessment and subjects' views of their problems. This study illustrates the complexities of coming for treatment and it emphasises the need for social and medical help.

MMPI subtypes for chronic phencyclidine (PCP) abusers.

The present study applied empirical clustering procedures to the MMPI protocols of 196 chronic phencyclidine (PCP) abusers. Subjects were randomly divided into two groups, and two methods of cluster analysis, the average linkage method and Ward's hierarchical procedure, were performed. Both cluster methods produced highly comparable results within each group, and the MMPI profiles found in each group were quite similar. Cluster analytic studies of other substance abuse populations are needed in order to replicate the MMPI profile types found in the present study. These investigations would lead to an empirical typology across various substance abuse populations that would depict developmental stages.

Behavioral response to buspirone in cocaine and phencyclidine withdrawal.

The effects of buspirone in treating cocaine and phencyclidine (PCP) withdrawal were studied. Withdrawal symptoms of these two street-drugs are thought to be due to norepinephrine, dopamine and possibly serotonin depletion. Buspirone acts by enhancing dopaminergic and noradrenergic firing as well by suppressing serotonergic activity. Thirty-two cocaine abusers and 24 PCP abusers were withdrawn over a 30-day period. Half of each group received buspirone 10 mg t.i.d. and the other half 10 mg placebo t.i.d. In the cocaine group, buspirone was significantly more effective from the fifth day onward. In the PCP group, significant improvement was seen on the thirtieth day. Delayed effectiveness in PCP is thought due to its actions at other neurotransmitter sites.

A comparison of alcoholic and nonalcoholic drug abusers.

A group of 329 hospitalized drug abusers were evaluated for a current or past diagnosis of alcoholism. The alcoholic drug-dependent patients (n = 169, 51.4%) were then compared with the nonalcoholic patients (n = 160, 48.6%) with regard to sociodemographic, clinical and family history characteristics. The alcoholics were significantly more likely to receive a DSM-III diagnosis of major depression, with melancholia; other Axis I diagnoses were equally distributed between the two groups. Antisocial personality disorder was also significantly more prevalent among the alcoholic patients. The alcoholics had somewhat longer drug histories and more vivid memories of their first drinking experiences; polydrug abuse, however, was no more common in this group. Finally, the first-degree relatives of the alcoholics had significantly more alcoholism than the first-degree relatives of the nonalcoholic patients. Implications regarding the relationship of alcoholism and other forms of substance abuse are discussed.

Drugs of abuse and the elicitation of human aggressive behavior.

The drug-violence relationship exists for several reasons, some direct (drugs pharmacologically inducing violence) and some indirect (violence occurring in order to attain drugs). Moreover, the nature of that relationship is often complex, with intoxication, neurotoxic, and withdrawal effects often being confused and/or confounded. This paper reviews the existing literature regarding the extent to which various drugs of abuse may be directly associated with heightened interpersonal violence. Alcohol is clearly the drug with the most evidence to support a direct intoxication-violence relationship. The literatures concerning benzodiazepines, opiates, psychostimulants, and phencyclidine (PCP) are idiosyncratic but suggest that personality factors may be as (or more) important than pharmacological ones. Cannabis reduces likelihood of violence during intoxication, but mounting evidence associates withdrawal with aggressivity. The literature on the relationship between steroids and aggression is largely confounded, and between 3,4-methylenedioxymethamphetamine (MDMA) and aggression insufficient to draw any reasonable conclusions. Conclusions and policy implications are briefly discussed.

Female PCP-using jail detainees: proneness to violence and gender differences.

Previous studies indicate that PCP users have different characteristics from other drug users and that female PCP use is more common than use among males. Furthermore, there is evidence that those who respond to PCP with violence may differ from those who do not. This study attempted to examine comprehensively the psychological, behavioral, and background factors among female jail inmates that may contribute to a PCP preference and subjects' perception of various behavioral states while using PCP. Female PCP users were further examined relative to male PCP users to differentiate them on the basis of these perceptual factors. A distinction was further made between females and males prone to PCP-induced violence and those who do not become violent with respect to the above psychological and behavioral measures. Our results showed differences between male and female PCP users that are discrepant with the assumption that men and women perceive similar drug-related experiences. In particular, female PCP using subjects reported more dysphoria and aggressiveness when not using PCP, while male subjects were more likely to report aggressive behavior and dysphoria under the influence. Overall, these results suggest that males who prefer PCP may be self-stimulating and females who prefer PCP may be attempting to self-medicate.

The self-reported effects of PCP on human aggression.

The elicitation of violent of psychotic behavior by phencyclidine (PCP) administration is well documented. There are indications, however, that behavioral responses to PCP may differ among PCP users as a function of background or personality characteristics. The present study examined 35 male jail inmates with histories of PCP use. Estimates of the nature and extent of drug use and self-reports of previous psychiatric hospitalizations were obtained in these subjects. The Buss-Durkee Hostility Inventory was modified to reflect behaviors under the two simulated conditions of "No PCP" and "PCP" use. Results showed that PCP use was related to increased levels of hostility in our subjects when present age, age of first use, the frequency of use and suspicion and assaultive behavior when not using PCP was considered. Also, subjects with a history of psychiatric hospitalizations reported higher levels of assault when using PCP than those without psychiatric histories. These data suggest that the self-reported behavioral results of PCP use are associated with certain personality traits and background features.

Phencyclidine and chemical "stroking".

The current wave of drug abuse is but the latest manifestation of the real human need for "stroking." Drugs which affect the pleasure center of the brain are prime objects of abuse. Phencyclidine ("PCP" or "angel dust") is a cyclohexylamine which has properties of the amphetamine-stimulants, the narcotic-depressants and the hallucinogens. Previously unrecognized population groups include children less than six years of age and pregnant women and their intoxicated offspring. Successful treatment of present and future patients must be multidisciplinary and will ultimately depend upon a clear understanding of the pharmacology, social psychology, politics, and economics of drugs of abuse.