Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036341 (schizophrenia)
 60,220 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Phencyclidine (PCP), a widely abused drug currently, has multiple pharmacological actions, including psychotomimetic [1], anesthetic [2], sympathomimetic [2], anticholinergic [3-7], and dopaminergic [8-10]. Similarly, PCP intoxication in man can present with diverse symptoms: schizophrenia-like delusions and hallucinations; mania; violence, dyskinetic, catatonic, or stereotyped movements; hypertension; and coma [11, 12]. There is general agreement that the treatment of PCP intoxication includes support of vital functions and acidification of the urine [13]. However, there is no known specific antidote for PCP toxicity. Although diazepam [13], haloperidol [14, 15], and chlorpromazine [16] have been reported to improve the agitation and psychotic symptoms caused by PCP, the therapeutic efficacy of these agents has rarely been documented with objective clinical measures. Recently we found that intramuscular physostigmine and haloperidol [17, 18] improved several symptoms of acute PCP intoxication as measured by the Brief Psychiatric Rating Scale (BPRS) [19].
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PMID:Phencyclidine intoxication: assessment of possible antidotes. 713 17

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.
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PMID:The urban epidemic of phencyclidine (PCP) use: clinical and laboratory evidence from a public psychiatric hospital emergency service. 721 23

Phencyclidine (PCP) is a dissociative anesthetic whose abuse is a growing problem. Historically, its effects have been considered remarkably like those of the schizophrenic state, but in vitro and in vivo neuropharmacologic data are somewhat inconsistent with the dopaminergic hypothesis of schizophrenia. The physiologic and psychiatric manifestations of PCP intoxication are diverse and somewhat dose dependent. Urine acidification may hasten drug excretion.
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PMID:Phencyclidine intoxication: insights into a growing problem of drug abuse. 743

Both stimulant-induced and phencyclidine (PCP)-induced psychoses have been proposed as models of the idiopathic psychosis of schizopherenia. In this two-part study, the phenomenology of the psychosis associated with a period of cocaine intoxication was evaluated retrospectively in 34 male crack cocaine-dependent patients without concomitant psychiatric disorder and then was compared with the psychosis of 16 actively psychotic schizophrenic men (without a history of drug or alcohol abuse in the past year). Certain First Rank Schneiderian Symptoms (FRSS) were more commonly observed in the schizophrenic patients (e.g., thought broadcasting, thought withdrawal) than in the cocaine addicts. In the second part of this study, we retrospectively examined the cocaine and PCP experiences of an additional 22 cocaine addicts who had a past history of separate periods of cocaine and PCP use. Overall, the frequency of FRSS recalled during periods of cocaine and PCP intoxication was similar. However, the psychosis related to cocaine intoxication was more associated with an intense suspiciousness and paranoia related to a fear of being discovered or harmed while using cocaine. PCP-induced psychosis was less associated with suspiciousness and more associated with delusions of physical power, altered sensations, and unusual experiences [e.g., out of body experiences, experiencing religious figures or events directly (e.g., being with Noah at the time of the Arc)]. As elements of both cocaine and PCP psychosis can be found in schizophrenia, a model integrating the mechanisms of several psychotogenic drugs may be more informative. Such an integrative model might better capture the heterogeneity of psychotic symptoms that can be seen in schizophrenia. Furthermore, different pharmacologic interventions (e.g., "anti-stimulant" versus "anti-PCP") might address different aspects of the positive symptom picture in schizophrenia.
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PMID:Phenomenologic comparison of the idiopathic psychosis of schizophrenia and drug-induced cocaine and phencyclidine psychoses: a retrospective study. 931 84

Phencyclidine (PCP) produces psychotomimetic effects in humans that resemble schizophrenia symptoms. In an effort to screen compounds for antipsychotic activity, preclinical researchers have investigated whether these compounds block PCP-induced behaviors in animals. In the present study, the atypical antipsychotic clozapine was tested in combination with an active dose of PCP in two-lever drug discrimination and mixed signalled-unsignalled differential-reinforcement-of-low-rates (DRL) procedures. PCP produced distinctive effects in each task: it substituted for the training dose in PCP discrimination and it increased the number of responses with short (<3 s) interresponse times as well as increasing overall response rates in the DRL schedule. Acute dosing with clozapine failed to alter the behavioral effects of PCP in either procedure even when tested up to doses that produced pharmacological effects alone. These results suggest that acute dosing with clozapine would not affect behaviors most closely associated with PCP intoxication. Further, they bring into question the utility of using PCP combination procedures in animals to screen for antipsychotic potential. Since chronic dosing is required for therapeutic efficacy of antipsychotics, future studies should focus on investigation of chronic dosing effects of these drugs in combination with PCP.
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PMID:Combinations of clozapine and phencyclidine: effects on drug discrimination and behavioral inhibition in rats. 1111 8

Some 40 years ago phencyclidine (PCP) was developed as the prototype of a proposed new class of 'dissociative' general anesthetics, so called because it induced a marked dissociation from the environment without complete loss of consciousness. In the earliest clinical trials of PCP anesthesia, it was observed that as many as half the subjects experienced severe psychotic reactions during and beyond emergence. This striking clinical observation at once marked the failure of PCP as a suitable general anesthetic, and the beginning of a remarkable new era in basic and clinical neuroscience which can serve as an example of the interaction between clinical observation and basic science. At once, clinical researchers turned their focus upon the characterization of the PCP-induced psychosis, and recognized striking similarities between PCP-induced symptoms and signs and both the negative and positive symptoms of schizophrenia, proposing the PCP psychosis as a new model of that illness. Several years later PCP suddenly emerged as a major drug of abuse, with the result that emergency rooms and psychiatric inpatient units were observing and treating large numbers of these patients, in many of whom a diagnosis of schizophrenia could not be ruled out until toxicological analyses were performed. This natural experiment yielded a huge amount of additional data, and contributed a strong public-health based impetus to research into the nature and treatment of PCP intoxication.
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PMID:Phencyclidine, excitatory amino acids, psychiatry and drug abuse: Historical perspectives on clinical-laboratory interactions. 2697 35