Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.1.8 (cholinesterase)
 12,691 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of physostigmine, a cholinesterase inhibitor, on the loss of consciousness induced by three different intravenous induction anesthetics, namely midazolam, etomidate and althesin at ED50, was studied in three comparable groups of patients. Ten min before induction, the first and second groups received physostigmine 8 micrograms/kg and 16 micrograms/kg, respectively, and the third group received 2 ml of saline solution. Physostigmine 16 micrograms/kg resulted in a significant decrease in the percentage of unconscious patients with midazolam (from 50% to 10%), but it did not modify the incidence with etomidate or althesin. Physostigmine at doses of 8 micrograms/kg and 16 micrograms/kg could cause 6.7% and 10% nausea, respectively. Although the mechanism of the drug interaction of physostigmine and midazolam is unclear, physostigmine could be used clinically to reverse post-anesthetic somnolence induced by midazolam.
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PMID:Effect of physostigmine on the loss of consciousness induced by midazolam, etomidate and althesin. 175 60

This case illustrates the effect of abnormal pseudocholinesterase on the metabolism and actions of chloroprocaine in a postpartum patient. The patient apparently could not adequately metabolize chloroprocaine which may have led to excessive somnolence intraoperatively. It also led to a prolonged chloroprocaine block (normally the block would last only 45-60 minutes) of 3 hours as well as to detectable serum chloroprocaine 5 hours after administration. Abnormal pseudocholinesterase was verified by the prolonged apnea following subsequent succinylcholine administration and by the fact that her dibucaine number at 6 weeks postpartum was indicative of a homozygote for the atypical cholinesterase variant or a heterozygote with 1 gene for the atypical variant and one for the silent variant. This case suggests that an abnormal reaction to chloroprocaine can occur in a patient with atypical cholinesterase and that an abnormal reaction to chloroprocaine has clinical implications beyond a prolonged epidural block. An abnormal reaction to chloroprocaine should alert the anesthesiologist to the possibility of a pseudocholinesterase deficiency which should suggest that the subsequent use of succinylcholine may result in a prolonged neuromuscular blockade.
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PMID:A prolonged chloroprocaine epidural block in a postpartum patient with abnormal pseudocholinesterase. 708 36

Diffuse Lewy body disease (DLB) is a neurodegenerative disorder characterized by dementia, fluctuations in mental status, hallucinations, and parkinsonism. Diffuse Lewy body disease is the second most common cause of dementia, following Alzheimer's disease. The treatment of DLB includes cholinergic therapy for cognitive impairment, atypical neuroleptics to alleviate hallucinations, and levodopa/carbidopa to improve parkinsonism. The recognition and diagnosis of DLB has critical treatment implications. Centrally acting cholinesterase inhibitors, such as rivastigmine, donepezil, and galantamine partially reverse decreased cortical cholinergic activity and may improve cognition and neuropsychiatric symptoms in DLB. Rivastigmine has been demonstrated to improve cognition and neuropsychiatric symptoms in patients with DLB without worsening parkinsonian features. Due to the potential adverse events associated with neuroleptics in this population, treatment with cholinesterase inhibitors is currently considered first-line therapy in the treatment of hallucinations and mental status fluctuations in DLB. Exquisite sensitivity to neuroleptic medications is a hallmark of DLB and life-threatening complications have been reported. Caution should be exercised when implementing antipsychotic therapy for the treatment of behavioral disturbances of DLB. When required, atypical neuroleptics with the least extrapyramdial side effects, such as quetiapine, should be used. The parkinsonian features of DLB may respond to dopaminergic therapy with levodopa. If parkinsonian symptoms result in clinical disability, a trial of levodopa is warranted. Unfortunately, dopaminergic medications may worsen hallucinations. Because dopamine agonists have a greater tendency to induce hallucinations and somnolence, levodopa is the treatment of choice for parkinsonism in DLB. Rapid eye movement (REM) sleep behavior disorder (RBD) is now recognized as a feature of DLB. Awareness of the presence of this symptom in patients with DLB is important and treatment with low dose clonazepam may help. Cholinergic aumentation may also improve these symptoms in patients with DLB.
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PMID:Diffuse Lewy Body Disease. 1158 27

The long-acting anticholinesterase, distigmine bromide (Ubretid), is widely used for the treatment of underactive neurogenic bladder. Therefore, we emphasize its hazardable side-effect of cholinergic crisis. A 78-year-old man with duodenal ulcer complained of nocturia, and was administered distigmine bromide 10 mg daily under the diagnosis of mild benign prostatic hypertrophy with underactive neurogenic bladder. It seemed that administration slightly improved his symptom but he developed bradycardia, dyspnea and drowsiness suddenly on the 4th day. Blood examination revealed extremely low cholinesterase in his serum, suggesting distigmine bromide intoxication. He was treated intensively with several intravenous injections of atropine, high-concentration oxygen and transfusion of fresh frozen plasma. Nevertheless, his condition did not recover, resulting in death of "cholinergic crisis" on the 6th day.
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PMID:[Cholinergic crisis following administration of distigmine bromide: a case report]. 1186 80

Pesticides, such as parathion, are metabolized by cytochrome p-450 system to paraoxon, which is a potent cholinesterase inhibitor. Paraoxonase (PON) catalyzes the hydrolysis of these toxic metabolites and protects against pesticide toxicity. A glutamine/arginine (Gln/Arg) polymorphism at amino acid position 192 of PON has been described. The Arg/Arg genotype is associated with higher serum paraoxonase activity compared to Gln/Gln. The Arg/Gln genotype is associated with intermediate serum PON activity. The potential association between PON genotype and symptoms of chronic pesticide toxicity was examined among 100 farm workers. As part of a cross-sectional study of pesticide toxicity among mixed-race farm workers in the Western Cape. South Africa, 100 farm workers were genotyped for polymorphism of the paraoxonase gene at amino acid position 192. Subjects with two or more of the following symptoms were considered to have evidence of chronic toxicity: abdominal pain, nausea, rhinorrhea, dizziness, headache, somnolence, fatigue, gait disturbance, limb numbness, paresthesias, limb pain, or limb weakness. In multivariable logistic regression analysis, the independent predictors of chronic toxicity were previous history of head trauma resulting in loss of consciousness (OR 2.8, 95% CI = 1.7-6.7), having worked as a pesticide applicator (OR 5.4, 95% CI = 3.2-8.9), and having one of the two "slow metabolism" (Gln/Gln or Gln/Arg) genotypes (OR 2.9, 95% CI = 1.7-6.9). Furthermore, the prevalence of chronic toxicity increased in a stepwise fashion from 15% among pesticide nonapplicators with a "fast metabolism" (Arg/Arg) genotype, to 42.9% among pesticide nonapplicators with "slow metabolism" (Gln/Gln or Gln/Arg) genotypes, to 58.8% among pesticide applicators with "fast metabolism" genotype, and 75.0% among pesticide applicators with "slow metabolism" genotypes (P = 0.001). Age, number of years on the job, smoking history, alcohol history, education level, plasma or red blood cell cholinesterase level, or previous history of acute organophosphate poisoning were not statistically significant predictors of chronic toxicity. The PON genotype is an important determinant of a farmworker's susceptibility to chronic pesticide poisoning.
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PMID:Association between human paraoxonase gene polymorphism and chronic symptoms in pesticide-exposed workers. 1262 27

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

The syndrome of dementia with Lewy bodies (DLB) is characterised by the clinical triad of fluctuating cognitive impairment, recurrent visual hallucinations and spontaneous motor features of Parkinsonism. In an attempt to define DLB as a distinct clinical syndrome separate from Alzheimer's disease (AD) and Parkinson's disease (PD) with dementia, a consensus workshop in 1995 established a new set of diagnostic criteria. Dementia that precedes or accompanies the onset of spontaneous (i.e., not neuroleptic-induced) Parkinsonism is termed DLB. In addition, fluctuations in alertness, cognition and function and visual hallucinations are emphasised and included as core features of DLB. The degree to which an individual patient exhibits cognitive impairment, behavioural problems and Parkinsonian features is variable. Therefore, treatment must be individualised. Although there are no officially approved drugs for DLB, limited experience from clinical trials, as well as past experience with the treatment of AD and PD patients, provide some basis for making drug choices. The cholinergic deficit seen in DLB makes cholinesterase inhibitor drugs the mainstay of treatment for cognitive impairment. This class of drugs has also shown therapeutic benefit in reducing hallucinations and other neuropsychiatric symptoms of the disease. Because of their relatively greater therapeutic window, cholinesterase inhibitors are also used as first-line therapy for the treatment of psychosis in DLB. Patients with DLB are extremely sensitive to the extrapyramidal side effects of neuroleptic medications. Thus, only atypical antipsychotic agents such as quetiapine, should be considered as alternative treatment for psychosis. Anxiety and depression are best treated with selective serotonin re-uptake inhibitors, whereas REM sleep behaviour disorder may be treated with low dose clonazepam. Parkinsonism responds to dopaminergic agents; however, precipitation or aggravation of hallucinosis may occur. Levodopa is preferred over dopamine agonists due to its lower propensity to cause hallucinations and somnolence. As the diagnostic criteria for DLB become more refined and validated by postmortem studies, it is hoped that rigorous, well-designed trials will be performed, aimed at alleviating the primary target symptoms of dementia, psychosis and Parkinsonism.
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PMID:Pharmacotherapy of dementia with Lewy bodies. 1459 56

Fluctuations in cognition and alertness (FC/FA) are key manifestations of dementia with Lewy bodies (DLB) and also have been recognized recently in patients with Parkinson's disease (PD) with dementia, a condition that shares important clinical, genetic, and neuropathologic characteristics with DLB. A comprehensive assessment of potential episodes of FC/FA is required for adequate clinical management, and several interesting clinical instruments are being developed for that purpose. FC/FA should be differentiated from episodes of excessive daytime sleepiness (EDS). Such diagnostic differentiation appears to be necessary, particularly in the light of the different therapeutic approaches to FA and EDS. Based on the deficit in cholinergic transmission observed in DLB patients, cholinesterase inhibitors, such as rivastigmine, may have a beneficial effect on FC/FA. Other therapies, such as melatonin or modafinil, require further investigation.
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PMID:Fluctuations in cognition and alertness in Parkinson's disease and dementia. 1550 41

Behavioral problems produce excess disability that can be potentially devastating in cognitively impaired patients. These behavioral symptoms can be a major cause of stress, anxiety and concern for caregivers. While psychotropic drugs are frequently used to control these symptoms, they have the potential for significant side effects, which include sedation, disinhibition, depression, falls, incontinence, parkinsonism and akathisias. On examination of the consequences of adverse events, somnolence, as well as postural instability and postural hypotension, have been noted. All patients with Alzheimer's disease (AD) and other progressive dementias will advance through stages of moderate-to-severe AD unless effective treatments suspend transition from mild deterioration to dementia, or competitive mortality truncates survival. Treatment trials suggest that these patients respond to both disease-modifying (such as inhibitors of cholinesterase and butirrylcholinesterase) and symptomatic (such as neuroleptics) agents. Relatively few studies have been conducted in this patient population, and more information regarding the type of behavioral disturbances exhibited, how best to measure them in this disabled population and their optimum treatment are urgently needed.
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PMID:Atypical neuroleptics as a treatment of agitation and anxiety in Alzheimer's disease: risks or benefits. 1673 18

Delusions are commonly encountered symptoms in patients with Alzheimer's disease and may lead to significant morbidity. The purpose of this article is to review all clinical trials to date focusing on the management of delusions in patients with Alzheimer's disease to determine the level of evidence for treatment. To achieve this objective, Medline was searched using the key words delusions, dementia, Alzheimer's disease and psychosis. Three main categories of treatment were identified: atypical antipsychotics, cholinesterase inhibitors, and other miscellaneous treatments. It was concluded that all forms of treatment were effective although the greatest burden of evidence existed for risperidone and donepezil. Side effects were noted in all forms of treatment and included somnolence and extrapyramidal effects for antipsychotic medications, whereas gastrointestinal effects were more prevalent in studies involving cholinesterase inhibitors. Further large scale, double-blind, randomized, controlled studies are required before a definitive conclusion can be reached. To our knowledge this is the only systematic review of this area.
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PMID:Treatment of delusions in Alzheimer's disease--response to pharmacotherapy. 1690 81


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