Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0042963 (vomiting)
 31,883 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cholinesterase inhibitors are currently the most established treatment strategy in Alzheimer's disease. The treatment effect appears mainly to be symptomatic. Effects on progression of the disease following long term treatment, and possible neuroprotective effects, have been investigated. Delay until nursing home placement has been reported. Three cholinesterase inhibitors, tacrine, donepezil and rivastigmine, are in clinical use. Other cholinesterase inhibitors, such as galantamine (galanthamine), metrifonate, physostigmine, eptastigmine, are currently under clinical evaluation. So far the efficacy appears to be comparable between the various cholinesterase inhibitors; treatment for up to 6 months has produced an improvement in Alzheimer's Disease Assessment Scale -- Cognitive Subscale score (ADAS-cog) of between 1.8 and 4.9 in patients with Alzheimer's disease. Tacrine, donepezil, galantamine and physostigmine are reversible inhibitors of acetylcholinesterase and butyrylcholinesterase, while metrifonate is considered to be an irreversible inhibitor and rivastigmine a pseudoirreversible inhibitor. Tacrine and physostigmine have lower bioavailability, 17 to 37% and 3 to 8%, respectively, than the other cholinesterase inhibitors such as rivastigmine, galantamine and donepezil (40 to 100%). The elimination half-life is considerably longer for donepezil (70 to 80h) in comparison to most of the other cholinesterase inhibitors (0.3 to 12h). Donepezil is therefore administered once daily in comparison to rivastigmine which is administered twice daily and tacrine which is administered 4 times daily. Simultaneous food intake lowers the plasma concentration of tacrine and reduces the adverse effects of rivastigmine. Drugs like theophylline and cimetidine have been reported to change the pharmacokinetics of tacrine and donepezil. In contrast, concomitant medication with various drugs with rivastigmine does not seem to cause any drug interactions in patients with Alzheimer's disease. Tacrine, donepezil and galantamine are metabolised via the cytochrome P450 (CYP) liver enzymes. Active metabolites are known for tacrine and galantamine. Rivastigmine is not metabolised via CYP enzymes, but via esterases and is excreted in the urine. Tacrine is associated with hepatotoxicity while other cholinesterase inhibitors seem devoid this adverse effect. Increased liver enzyme values have been observed in 49% of patients with Alzheimer's disease treated with tacrine. Rechallenge with tacrine reduces the incidence of elevated liver enzyme levels. Peripheral cholinergic adverse effects are common for the cholinesterase inhibitors, with an incidence ranging between 7 to 30%. For some cholinesterase inhibitors, such as rivastigmine, the cholinergic adverse effects such as nausea, vomiting, dizziness, diarrhoea and abdominal pain can be reduced by slowing the rate of dose titration.
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PMID:Cholinesterase inhibitors in the treatment of Alzheimer's disease: a comparison of tolerability and pharmacology. 988 90

The management of dementia patients encompasses pharmacologic, behavioral, and psychosocial intervention strategies. Before pharmacologic intervention is instituted, it is important that sources of excess disability and comorbidity be eliminated or reduced. Identification of comorbid medical and psychiatric conditions, such as depression and delirium, should be identified and appropriately treated. Providing caregivers with education, support, and practical advice is a critical component of the management of the demented patient. The current standard of care for pharmacologic management of the cognitive and functional disabilities of AD consists of the combination of a cholinesterase inhibitor and high-dose vitamin E. This standard is based on the results of large-scale, double-blind, placebo-controlled trials. Cholinesterase inhibitors are the only FDA-approved pharmacologic treatments for AD. Cholinesterase inhibitors have been shown to be effective in the treatment of the cognitive, behavioral, and functional deficits of AD. Large-scale placebo-controlled trials of tacrine, donepezil, rivastigmine, and galantamine have demonstrated moderate benefits in patients with mild to moderate AD. Donepezil, rivastigmine, and galantamine are the first-line choices in the treatment of AD because of their lack of hepatotoxicity, ease of administration, few significant drug-drug interactions, and mild to moderate side effects. There are few contraindications to the use of cholinesterase inhibitors. Known hypersensitivity to a specific drug or its derivatives is the only true contraindication. Cautious administration of cholinesterase inhibitors is advised in patients who have a previous history of allergy or adverse reactions to prior cholinesterase inhibitors, severe liver disease, preexisting bradycardia, peptic ulcer disease, current alcoholism, asthma, or chronic obstructive pulmonary disease. Nausea, vomiting, diarrhea, and anorexia are the most common side effects of cholinesterase inhibitors. These gastrointestinal side effects can be minimized by gradual dose increases, administration with food, adequate hydration, and judicious use of an antiemetic. Vitamin E has been demonstrated to slow the progression of AD in several small and one large placebo-controlled trials. Because of its low cost and safety, it is recommended in addition to a cholinesterase inhibitor for the treatment of AD. There are no FDA-approved treatments for DLB and VaD. One small placebo-controlled trial demonstrated that rivastigmine may be effective in the treatment of DLB. More large-scale placebo-controlled trials are needed to confirm the results of this study. Treatment of VaD focuses on the control, identification, and management of cerebrovascular disease and vascular risk factors. Although there are no peer-reviewed reports on the efficacy of cholinesterase inhibitors for VaD or mixed AD/VaD, early reports suggest that these agents may also be effective for mixed AD/VaD. The indications for the use of cholinesterase inhibitor drugs are eventually likely to broaden to include DLB, mixed AD/VaD, and AD in its more advanced stages.
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PMID:Pharmacologic treatments of dementia. 1217 Oct 61

Cholinesterase inhibitors (ChE-Is) are the standard of therapy for treatment of patients with Alzheimer disease (AD) and are the only class of drugs approved by the Food and Drug Administration (FDA) for treatment of this condition. This review provides evidenced-based recommendations for use of ChE-Is in clinical practice. The author searched computerized literature databases of the approved ChE-Is widely used in clinical practice (donepezil, rivastigmine, and galantamine), and extended the review with bibliographies from identified articles and package inserts of information reviewed by the FDA. Double-blind, placebo-controlled trials providing Class I evidence were used as data sources whenever possible. Articles with Class II and Class III data were used when Class I data were unavailable. In general, ChE-Is exert modest reproducible effects in patients with mild-to-moderate AD. Drug-placebo differences are evident on global and cognitive measures. Secondary outcomes, including measures of activities of daily living and behavior, also typically demonstrate drug-placebo differences in favor of the active agent. Head-to-head trials of ChE-Is are limited; existing trials suggest no major differences in efficacy. Observations from clinical trials imply that early initiation of therapy is associated with greater long-term benefits. Clinical trials with withdrawal periods indicate that withdrawal and re-initiation of treatment may result in loss of benefit. Open-label extensions of double-blind trials show that differences in level of functioning between treated populations and extrapolated for untreated populations continue for several years. Side effects of ChE-Is include nausea, vomiting, diarrhea, and anorexia, and are more frequent during dose escalation than maintenance therapy. Clinical-trial populations differ substantially from unselected populations of AD patients, and these selection biases demand that efficacy data from clinical trials be generalized with caution.
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PMID:Use of cholinesterase inhibitors in clinical practice: evidence-based recommendations. 1261 43

Carbofuran belongs to the group of N-methylcarbamate insecticides used for the control of soil-dwelling and foliar-feeding insects in various crops; its consumption totals approximately 20,000 tonnes per year. Although the neurological effects on human beings have been well documented, little is known on its impact on the genome. A 38-year-old, healthy male worker employed in a carbofuran production facility accidentally inhaled the dust of the active ingredient carbofuran. Thirty minutes later, he experienced weakness, fatigue, perspiration, breathing difficulties, cephalalgia, disorientation, abdominal pain and vomiting. Blood samples were taken to measure cholinesterase activity, and to perform the alkaline comet assay and micronucleus assay combined with pancentromeric probes. Analyses were repeated 72 hr after intoxication and compared with the results obtained from regular monitoring conducted 10 days prior to the accident. Cholinesterase activity showed the highest correlation with the number of apoptotic cells, comet assay tail length, and number of long-tailed nuclei, suggesting that these are the genomic end-points primarily affected by carbofuran intake. Only a weak correlation was detected for the total number of micronuclei, centromere-containing micronuclei and nuclear buds. Since those end-points increased significantly 72 hr after the accident, they could be considered as late biomarkers of the effects of carbofuran intoxication. The results of this report suggest that, in the interests of higher standards in risk assessment and health hazard protection, periodical medical examination of carbamate-exposed populations should include genotoxicity testing in addition to the assessment of cholinesterase activity.
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PMID:Cholinesterase-inhibiting and genotoxic effects of acute carbofuran intoxication in man: a case report. 1869 99

Acetyl Cholinesterase (AChE) inhibitors such as Donepezil, Rivastigmine and Galantamine are approved by US-FDA as first line drugs to treat the cognitive symptoms of Alzheimer's disease (AD). Their beneficial effects are attributed to their ability to elevate endogenous acetylcholine (ACh) at the M1 muscarinic receptor in the brain. However, their side effects such as nausea, vomiting, dizziness, insomnia, loss of appetite and altered heart rate are related to non-specific activation of M2-M5 muscarinic subtypes in various tissues. It is logical, therefore, to develop agonists with M1 receptor selectivity. Unfortunately, this is limited due to a high degree of orthosteric site homology among the receptor subtypes. In contrast, their allosteric sites are unique and, therefore, allow selective targeting using positive allosteric modulators (PAMs). PAMs of M1 receptors are devoid of agonist activity, however, when bound they enhance the binding affinity of orthosteric ligand, ACh. The major limitation of these PAMs is their bioavailability in the brain. In the current hypothesis, we propose surface modified nano-lipid drug conjugates (LDC-NPs) of PAMs of M1 receptors to improve their bioavailability in brain. When co-administered with AChE inhibitors they are expected to increase their efficacy and reduce their therapeutic dose and side effects.
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PMID:Surface modified nano-lipid drug conjugates of positive allosteric modulators of M1 muscarinic acetylcholine receptor for the treatment of Alzheimer's disease. 2835 83