Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0030567 (Parkinson's disease)
 63,064 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Following acceptance of clozapine as a superior antipsychotic agent with low risk of adverse extrapyramidal syndromes (EPS), such as dystonia, parkinsonism, akathisia or tardive dyskinesia, several novel antipsychotic drugs have been developed with properties modelled on those of clozapine. Though generally considered 'atypical' in their relatively low risk of inducing EPS, these agents vary considerably in their pharmacology and impact on neurological functioning. Although few comparative data are available, the atypical antipsychotics can be tentatively ranked by EPS risk (excluding akathisia and neuroleptic malignant syndrome) in the following order: clozapine < quetiapine < olanzapine = ziprasidone. At higher doses, risperidone is ranked with a higher EPS risk than olanzapine and ziprasidone, but its risk of EPS is lower with lower doses. In general, this ranking is inversely related to antidopaminergic (D2 receptor) potency. The high antiserotonergic (5-HT2A receptor) potency of risperidone, clozapine, ziprasidone and olanzapine, but not quetiapine, as well as the antimuscarinic activity of olanzapine and clozapine may also limit EPS. For the treatment of psychotic reactions to dopamine agonist therapy in Parkinson's disease, clozapine is both effective and relatively well tolerated; quetiapine may be tolerated, olanzapine is not well tolerated, risperidone is poorly tolerated, and amisulpride and ziprasidone have not been well evaluated. Clozapine, perhaps because of its anticholinergic activity, can reduce parkinsonian tremor. It is useful for ongoing psychosis with tardive dyskinesia, especially for dystonic features. No atypical antipsychotic is clearly effective for motor abnormalities in Huntington's disease or Tourette's syndrome, and the effect of these drugs on other neurological disorders have been well evaluated in only small numbers of patients. In summary, with the exception of clozapine, and perhaps quetiapine, atypical antipsychotics have brought only relative avoidance of EPS, strongly encouraging continued searches for novel antipsychotic agents.
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PMID:Effects of newer antipsychotics on extrapyramidal function. 1177 17

Drug-induced psychosis is one of the most disabling complications of advancing Parkinson's disease. It has also been one of the most difficult to treat. Clozapine was the first medication shown to be safe and effective in this setting, and it remains the standard by which newer atypical antipsychotics are measured. However, due to the small but significant risk of agranulocytosis and the need for frequent blood testing, alternatives have been sought. Risperidone, olanzapine, and quetiapine are new atypical antipsychotics that have each been proposed as an alternative to clozapine, but the literature concerning their use in Parkinson's disease is conflicted and confusing. Although quetiapine appears to be the best current choice, none of these medications have equaled clozapine's ability to safely treat drug-induced psychosis without the risk of worsening parkinsonism.
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PMID:Parkinson's disease: the treatment of drug-induced hallucinations and psychosis. 1189 37

Data from clinical trials reviewed in this article fulfill predictions based on preclinical findings that atypical antipsychotic drugs are associated with a reduced potential for inducing extrapyramidal symptoms (EPS) and other movement disorders. Atypical drugs have been shown to reduce all subtypes of acute EPS, the frequency of EPS-related patient dropouts, and the need for concomitant antiparkinsonian drug use. Clozapine remains superior to other atypicals in treating psychosis without worsening motor symptoms in patients with Parkinson's disease. Atypicals may be selectively advantageous in treating schizophrenic patients with a predisposition to catatonia. Although the risk of developing lethal neuroleptic malignant syndrome may be diminished with atypical drugs, clinicians must remain alert to the signs of this disorder. Atypicals have reduced liability for inducing tardive dyskinesia (TD) and show antidyskinetic properties in patients with preexisting TD. Passive resolution of TD may be facilitated in some patients by the use of these agents. Thus, the risk of movement disorders has become only one of several considerations in choosing among antipsychotic drugs.
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PMID:Movement disorders associated with atypical antipsychotic drugs. 1191 70

(1) Psychotic disorders occurring in patients with Parkinson's disease are usually linked to antiparkinsonian treatments. Tapering the dose of dopaminergic or anticholinergic drugs does not always yield a satisfactory balance between the psychotic and motor disorders. Most neuroleptics tend to worsen extrapyramidal manifestations and are contraindicated in combination with dopaminergic agents. Their assessment in patients with Parkinson's disease has been limited. (2) Clozapine, a neuroleptic, is now indicated in this type of patient. (3) The evidence comes from two double-blind placebo-controlled trials, each involving 60 patients. In these trials, 40% of patients lost all their psychotic disorders on low-dose clozapine, usually with no worsening of parkinsonian manifestations. (4) In clinical trials of clozapine in Parkinson's disease, the incidence of neutropenia was between 2 and 3%, and that of agranulocytosis 0.3%. The risks of myocarditis, dilated myocardiopathy and malignant neuroleptic syndrome associated with clozapine call for strict pharmacovigilance. (5) In practice, when adjusting antiparkinsonian treatment fails to strike a balance between psychotic and parkinsonism disorders, clozapine is the standard neuroleptic. It should be used with care, however, because of its adverse effects.
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PMID:Clozapine: new preparation. A last resort for parkinsonian patients with psychosis. 1198 66

Abrupt clozapine withdrawal can cause rebound psychosis and severe somatic symptoms in psychiatric patients. We report on the case of an advanced Parkinson's disease patient who developed myoclonus, tremor, rigidity, hyperreflexia, and stupor after abrupt clozapine withdrawal. The patient's symptoms resolved with treatment with cyproheptadine. This clinical picture suggests serotonergic rebound as an explanation for the patient's symptoms, although other pharmacological mechanisms are possible. Clozapine should be gradually withdrawn over a period of 1 to 2 weeks when possible, and abruptly discontinued only when necessary.
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PMID:Clozapine withdrawal symptoms in a Parkinson's disease patient. 1246 85

The present article is meant to suggest an approach to the guidelines for the therapy of sleep disturbances in Parkinson's Disease (PD) patients.The factors affecting the quality of life in PD patients are depression, sleep disturbances and dependence. A large review of the literature on sleep disturbances in PD patients, provided the basis for the following classification of the sleep-arousal disturbances in PD patients. We suggest a model based on 3 steps in the treatment of sleep disturbances in PD patients. This model allowing the patient, the spouse or the caregiver a quiet sleep at night, may postpone the retirement and the institutionalization of the PD patient. I. Correct diagnosis of sleep disorders based on detailed anamnesis of the patient and of the spouse or of the caregiver. One week recording on a symptom diary (log) by the patient or the caregiver. Correct diagnosis of sleep disorders co morbidities. Selection of the most appropriate sleep test among: polysomnography (PSG), multiple sleep latency test (MSLT), multiple wake latency test (MWLT), Epworth Sleepiness Scale, actigraphy or video-PSG. II. The nonspecific therapeutic approach consists in: a) Checking the sleep effect on motor performance, is it beneficial, worse or neutral. b) Psycho-physical assistance. c) Dopaminergic adjustment is necessary owing to the progression of the nigrostriatal degeneration and the increased sensitivity of the terminals, which alter the normal modulator mechanisms of the motor centers in PD patients. Among the many neurotransmitters of the nigro-striatal pathway one can distinguish two with a major influence on REM and NonREM sleep. REM sleep corresponds to an increased cholinergic receptor activity and a decreased dopaminergic activity. This is the reason why REM sleep deprivation by suppressing cholinergic receptor activity ameliorates PD motor symptoms. L-Dopa and its agonists by suppressing cholinergic receptors suppress REM sleep. The permanent adjustment according to the progression of the degenerative process of the disease will diminishe aggravation. The following types of sleep-arousal disturbances have to be considered in PD patients: - Sleep Disturbances, Light Fragmented Sleep (LFS), Abnormal Motor Activity During Sleep (AMADS), REM Behavior Disorders (RBD), Sleep Related Breathing Disorders (SRBD), Sleep Related Hallucinations (SRH), Sleep Related Psychotic Behavior (SRPB). - Arousal Disturbances, Sleep Attacks (SA), Excessive Daytime Sleepiness (EDS), Each syndrome has to receive a score according to its severity. III. The specific therapy consists in: LFS: Benzodiazepines & Nondiazepines. AMADS: Clonazepam, Opioid, Apomorphine infusion; RBD: Clonazepam and dopaminergic agonists; SRBD: CPAP, UPPP, nasal interventions, losing weight; SRH: Clozapine, Risperidone; SRPD: Nortriptyline, Clozapine, Olanzepine; SA-adjustment; EDS-arousing drugs. Each therapeutic approach must be tailored to the individual PD patient.
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PMID:Sleep disturbances in Parkinsonism. 1258 74

Parkinson's disease is a neuropsychiatric disease with multiple psychic disorders. They mainly result from a combination between neuropathogical lesions and antiparkinsonian drugs. The most frequent psychic disorders are depression and psychosis. So far, pharmacological treatments of depression has been poorly evaluated. It is suggested that the first-line treatment of depression in Parkinson's disease is the class of the Selective Serotonin Reuptake Inhibitors. The occurrence of worsening in parkinsonism and agitation in rare cases necessitates a meticulous clinical follow-up. The treatment of psychosis is based on the reduction of antiparkinsonian medications, by tapering and stopping, if necessary, the drugs with the highest risk-to-benefit ratio first. When psychosis persists despite a simple levodopa monotherapy, then an antipsychotic drug is added. Clozapine is the only officially approved drug for psychosis in Parkinson's disease. Two double blind studies showed a clear antipsychotic effect without worsening of parkinsonism. Quetiapine, another atypical neuroleptic drug without risk of blood dyscrasia may prove to be as effective than clozapine. Olanzapine and risperidone can aggravate parkinsonism and should be used only as a last resort. Future studies will precise the place of anticholinesterases in the treatment of psychosis associated with dementia.
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PMID:[Psychic disorders] 1269 Mar 23

Parkinson's disease is a neuropsychiatric disease with multiple psychic disorders. They mainly result from a combination between neuropathological lesions and antiparkinsonian drugs. The most frequent psychic disorders are depression and psychosis. So far, pharmacological treatments of depression has been poorly evaluated. It is suggested that the first-line treatment of depression in Parkinson's disease is the class of the Selective Serotonin Reuptake Inhibitors. The occurrence of worsening in parkinsonism and agitation in rare cases necessitates a meticulous clinical follow-up. The treatment of psychosis is based on the reduction of antiparkinsonian medications, by tapering and stopping, if necessary, the drugs with the highest risk-to-benefit ratio first. When psychosis persists despite a simple levodopa monotherapy, then an antipsychotic drug is added. Clozapine is the only officially approved drug for psychosis in Parkinson's disease. Two double blind studies showed a clear antipsychotic effect without worsening of parkinsonism. Quetiapine, another atypical neuroleptic drug without risk of blood dyscrasia may prove to be as effective than clozapine. Olanzapine and risperidone can aggravate parkinsonism and should be used only as a last resort. Future studies will precise the place of anticholinesterases in the treatment of psychosis associated with dementia.
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PMID:[Psychic disorders]. 1269 Jun 72

Increasingly, atypical antipsychotic drugs are prescribed for elderly patients with symptoms of psychosis and behavioral disturbances. These symptoms often occur in patients with Alzheimer's disease, other dementias, or Parkinson's disease. As the average age of Americans increases, the prevalence of Alzheimer's disease and Parkinson's disease will rise accordingly. Although nonpharmacologic treatments for behavioral disturbances should be tried first, medications often are needed to enable the patient to be adequately cared for. Current guidelines recommend using risperidone and olanzapine to treat psychosis in patients with Alzheimer's dementia. Quetiapine and clozapine are recommended for treatment of psychosis in patients with Parkinson's disease. Additional research is needed for a recently approved agent, ziprasidone. To minimize side effects, these medications should be started at low dosages that are increased incrementally. Drug interactions, especially those involving the cytochrome P450 system, must be considered. Clozapine's potentially lethal side effects limit its use in the primary care setting. Informed use of atypical antipsychotic drugs allows family physicians to greatly improve quality of life in elderly patients with dementia and behavior disturbances.
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PMID:Use of atypical antipsychotic drugs in patients with dementia. 1531 32

Psychosis only rarely occurs in patients with untreated Parkinson's disease. Much more commonly, psychosis is induced by drug therapy for Parkinson's disease and is the strongest known risk factor for nursing home placement. Delusions are less frequent than hallucinations, but are more concerning as they are often paranoid in nature. Treatment begins with a search for correctable infectious, toxic, and metabolic aetiologies. If symptoms persist, anti-Parkinson's disease medications are slowly reduced. However, withdrawal of these drugs usually worsens parkinsonism and is often not tolerated. Certain atypical antipsychotics can be used to treat psychosis without compromising motor function. The choice of atypical antipsychotic is largely based on ease of use and adverse effect profile as most have comparable efficacy in improving psychosis. Currently, there are five marketed atypical drugs - clozapine, risperidone, olanzapine, quetiapine and ziprasidone. Ziprasidone is the only agent whose adverse effect profile has not been reported in Parkinson's disease. The most common adverse effects of clozapine in Parkinson's disease are sedation, orthostatic hypotension and sialorrhoea. Sedation is generally helpful since these patients are frequently awake at night and tend to have worse behavioural problems then. Clozapine does not induce deterioration of motor function, but it has the potential to cause agranulocytosis, which is idiosyncratic and not dose-related. In risperidone-treated Parkinson's disease patients, reported adverse effects include somnolence, sialorrhoea, dizziness, palpitations, constipation, delirium, fatigue, leg cramps, depression, urinary incontinence and hypotension. Although in some Parkinson's disease studies, risperidone has been well tolerated, others have shown that many patients are unable to tolerate the drug due to deterioration of motor function. While an initial study of olanzapine in Parkinson's disease psychosis showed the drug to be effective without deterioration of motor function, succeeding reports demonstrated a deleterious effect of the drug on motor functioning. The most common adverse effects of quetiapine in Parkinson's disease patients are sedation and orthostatic hypotension. There is a lack of double-blind trials; however, cumulative reports involving >200 Parkinson's disease patients strongly suggest that quetiapine is well tolerated and effective. Unlike clozapine, it does not improve tremor and may induce mild deterioration of motor function. Recently, cholinesterase inhibitors have been reported to alleviate psychosis in Parkinson's disease. Although ondansetron, an antiemetic with antiserotonergic properties, has been reported to relieve psychosis in Parkinson's disease, its prohibitive cost has prevented further study in this population. Electroconvulsive treatment is generally reserved for the patient with psychotic depression who is unable to tolerate any pharmacological therapy.
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PMID:Treatment of psychosis in Parkinson's disease: safety considerations. 1281 32


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