Low-dose clozapine for the treatment of drug-induced psychosis in Parkinson's disease. The Parkinson Study Group.
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BACKGROUND: Drug-induced psychosis is a difficult problem to manage in patients with Parkinson's disease. Multiple open-label studies have reported that treatment with clozapine at low doses ameliorates psychosis without worsening parkinsonism. METHODS: We conducted a randomized, double-blind, placebo-controlled trial of low doses of clozapine (6.25 to 50 mg per day) in 60 patients at six sites over a period of 14 months. The patients (mean age, 72 years) had idiopathic Parkinson's disease and drug-induced psychosis of at least four weeks' duration. All the patients continued to receive fixed doses of antiparkinsonian drugs during the four weeks of the trial. Blood counts were monitored weekly in all the patients. RESULTS: The mean dose of clozapine was 24.7 mg per day. The patients in the clozapine group had significantly more improvement than those in the placebo group in all three of the measures used to determine the severity of psychosis. The mean (+/-SE) scores on the Clinical Global Impression Scale improved by 1.6+/-0.3 points for the patients receiving clozapine, as compared with 0.5+/-0.2 point for those receiving placebo (P<0.001). The score on the Brief Psychiatric Rating Scale improved by 9.3+/-1.5 points for the patients receiving clozapine, as compared with 2.6+/-1.3 points for those receiving placebo (P=0.002). The score on the Scale for the Assessment of Positive Symptoms improved by 11.8+/-2.0 points for the patients receiving clozapine, as compared with 3.8+/-1.9 points for those receiving placebo (P=0.01). Seven patients treated with clozapine had an improvement of at least three on the seven-point Clinical Global Impression Scale, as compared with only one patient given placebo. Clozapine treatment improved tremor and had no deleterious effect on the severity of parkinsonism. In one patient, clozapine was discontinued because of leukopenia. CONCLUSIONS: Clozapine, at daily doses of 50 mg or less, is safe and significantly improves drug-induced psychosis without worsening parkinsonism. (+info)
5-HT modulation of dopamine release in basal ganglia in psilocybin-induced psychosis in man--a PET study with [11C]raclopride.
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The modulating effects of serotonin on dopamine neurotransmission are not well understood, particularly in acute psychotic states. Positron emission tomography was used to examine the effect of psilocybin on the in vivo binding of [11C]raclopride to D2-dopamine receptors in the striatum in healthy volunteers after placebo and a psychotomimetic dose of psilocybin (n = 7). Psilocybin is a potent indoleamine hallucinogen and a mixed 5-HT2A and 5-HT1A receptor agonist. Psilocybin administration (0.25 mg/kg p.o.) produced changes in mood, disturbances in thinking, illusions, elementary and complex visual hallucinations and impaired ego-functioning. Psilocybin significantly decreased [11C]raclopride receptor binding potential (BP) bilaterally in the caudate nucleus (19%) and putamen (20%) consistent with an increase in endogenous dopamine. Changes in [11C]raclopride BP in the ventral striatum correlated with depersonalization associated with euphoria. Together with previous reports of 5-HT receptor involvement in striatal dopamine release, it is concluded that stimulation of both 5-HT2A and 5-HT1A receptors may be important for the modulation of striatal dopamine release in acute psychoses. The present results indirectly support the hypothesis of a serotonin-dopamine dysbalance in schizophrenia and suggest that psilocybin is a valuable tool in the analysis of serotonin-dopamine interactions in acute psychotic states. (+info)
Epileptic psychoses and anticonvulsant drug treatment.
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Forty four consecutive patients with epilepsy and psychoses were studied retrospectively for psychotic episodes associated with changes in antiepileptic drug therapy. Twenty seven patients (61%) developed their first episode of psychosis unrelated to changes in their antiepileptic drug regimen. Twenty three of these patients developed psychoses with temporally unrelated changes in seizure frequency. Many patients had chronic schizophrenia-like psychotic symptoms. Seventeen patients (39%) developed their first episode of psychosis in association with changes in their antiepileptic drug regimen. Twelve patients developed psychoses temporally related to seizure attenuation or aggravation. Many of their psychotic symptoms were polymorphic with a single episode or recurrent episodes. No marked differences were found in the various clinical backgrounds between the two groups. In the drug-related group, seven patients developed psychoses after starting add-on therapy with a new antiepileptic drug, six after abruptly discontinuing their drugs, and four after taking an overdose of antiepileptic drugs. Based on the present findings, drug regimens should be changed gradually and compliance should be maintained to prevent epileptic psychoses. (+info)
Acute psychotic symptoms induced by topiramate.
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The incidence of psychosis during clinical trials of topiramate was 0.8%, not significantly different from the rate for placebo or reported rates of psychosis in patients with refractory epilepsy. We observed psychotic symptoms in five patients soon after initiation of topiramate therapy. We performed a retrospective chart review of the first 80 patients who began on topiramate after approval for clinical use, between January and April 1997. Symptoms suggestive of psychosis, including hallucinations and delusions, were sought for analysis. Cognitive effects such as psychomotor slowing, confusion, and somnolence were not included. Five patients developed definite psychotic symptoms 2 to 46 days after beginning topiramate. Dosages at symptom onset were 50-400 mg/day. Symptoms included paranoid delusions in four patients and auditory hallucinations in three. Symptoms of psychosis and other psychiatric symptoms resolved quickly with discontinuation of topiramate in three patients, dose reduction from 300 to 200 mg/day in one and with inpatient treatment and neuroleptics in another. One patient had a history of auditory hallucinations, one of aggressive and suicidal thoughts, but three had no significant psychiatric history. Physicians should be aware of the possibility of psychotic symptoms, even in patients without a previous psychiatric history, when prescribing topiramate. Symptoms resolve quickly with discontinuation. (+info)
Characterization of MK-801-induced behavior as a putative rat model of psychosis.
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The objective of this study was to characterize the behavior induced by the N-methyl-D-aspartate receptor antagonist MK-801 (dizocilpine maleate) in rats as a model of psychosis. The temporal profile, dose dependence, age, and sex differences of the behavior are described. A gas chromatographic method for the analysis of MK-801 in plasma and brain was developed. Female rats showed 4 to 10 times more MK-801-induced behavior and displayed around 25 times higher serum and brain concentrations of MK-801 than male rats. Twenty-one neuroactive compounds, including a number of excitatory amino acid-active substances, were tested for the effect on MK-801-induced behavior. Neuroleptics blocked MK-801-induced behavior in a dose-dependent manner that correlated to their antipsychotic potency in humans. Adenosine receptor agonists and an N-methyl-D-aspartate receptor-associated glycine site antagonist showed putative antipsychotic effects. In conclusion, MK-801-induced behavior represents a rat excitatory amino acid hypofunction model of psychosis that appears to be of clinical relevance and may be of value in the search for new antipsychotic agents. (+info)
Effects of repeated high-dose methamphetamine on local cerebral glucose utilization in rats.
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Repeated administration of high doses of methamphetamine (MAP) to rats can induce long-lasting neurotoxicity which may be related to permanent psychotic symptoms and negative symptoms in some MAP psychotic patients. In this study, we used the 2-[14C]deoxyglucose (2DG) method to analyze the effects of repeated MAP administration (12.5 mg/kg, i.p., 4 times every 2 hr within a day) 14 days and 60 days after drug administration. The results showed a widespread (26 of the 43 regions examined) decreases in the regional cerebral glucose utilization. The regions with decrease metabolism included all the extrapyramidal systems, the hippocampus formation and dorsal raphe nucleus. Rats tested 60 days after drug administration has similar finding to those with a 14-day abstinent period. The results of the functional change in this study provide support for the neurotoxic effects of repeated high dose MAP administration in rats. Furthermore, the neurotoxic effects are selective and long-lasting. We suggested the MAP neurotoxic model can be used to study the permanent psychosis and negative symptoms of MAP-induced psychosis in humans. (+info)
A case of interferon alpha-induced manic psychosis in chronic hepatitis C.
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It is well known that mood disorder such as depression occasionally develops during interferon (IFN) therapy for chronic viral hepatitis. So far, however, IFN-induced manic disorder has been rarely reported. We present a case of manic psychosis which developed during IFN treatment for chronic hepatitis C. A 35-year-old man with chronic hepatitis positive for hepatitis C virus RNA in serum was treated with natural IFN alpha with a daily dosage of 5 million units. Six weeks later he complained of insomnia, and then became exhilarated, talkative, restless and aggressive. Since the mental state was compatible with manic disorder, IFN therapy was immediately ceased. Simultaneously, psychotropic drugs were administered. One week later, the psychiatric disturbances disappeared. He has been keeping his usual social interactions without the psychotropic drugs after that. It is suggested that manic psychosis happened secondary to IFN alpha treatment. (+info)
Psychotic episodes during zonisamide treatment.
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Several articles have appeared over the last years devoted to mental side effects during zonisamide (ZNS) treatment. In this study, we were particularly interested in psychotic episodes. Seventy-four epileptic patients with a history of ZNS treatment were surveyed retrospectively over the period spanning 1 March 1984 to 30 June 1994. They were divided into two groups according to the presence or absence of psychotic episodes during ZNS treatment. We analysed various factors pertaining to psychotic episodes during ZNS treatment. Of the 74 patients 14 had psychotic episodes. We found that the incidence of psychotic episodes during ZNS treatment was several times higher than the previously reported prevalence of epileptic psychosis, and that the risk of psychotic episodes was higher in young patients. In 13 patients, psychotic episodes occurred within a few years of commencement of ZNS. In children, obsessive-compulsive symptoms appeared to be related to psychotic episodes. It is important to terminate ZNS as soon as possible if psychotic episodes develop and never restart, even if seizures become worse. It cannot definitely be proved that ZNS causes psychotic episodes, as information on mental side effects during ZNS monotherapy is scant, but it does appear likely that ZNS contributes to psychotic episodes during polytherapy. (+info)