Donepezil Health Dictionary

Donepezil: From 2 Different Sources


A drug used for the symptomatic treatment of mild to moderate DEMENTIA only in ALZHEIMER’S DISEASE. Around four in ten patients may bene?t by a reduction in the rate of cognitive and non-cognitive deterioration.
Health Source: Medical Dictionary
Author: Health Dictionary

Alzheimer’s Disease

Alzheimer’s disease is a progressive degenerating process of neural tissue affecting mainly the frontal and temporal lobes of the BRAIN in middle and late life. There is probably a genetic component to Alzheimer’s disease, but early-onset Alzheimer’s is linked to certain mutations, or changes, in three particular GENES. Examination of affected brains shows ‘senile plaques’ containing an amyloid-like material distributed throughout an atrophied cortex (see AMYLOID PLAQUES). Many remaining neurons, or nerve cells, show changes in their NEUROFIBRILS which thicken and twist into ‘neuro?brillary tangles’. First symptoms are psychological with insidious impairment of recent memory and disorientation in time and space. This becomes increasingly associated with diffculties in judgement, comprehension and abstract reasoning. After very few years, progressive neurological deterioration produces poor gait, immobility and death. When assessment has found no other organic cause for an affected individual’s symptoms, treatment is primarily palliative. The essential part of treatment is the provision of appropriate nursing and social care, with strong support being given to the relatives or other carers for whom looking after sufferers is a prolonged and onerous burden. Proper diet and exercise are helpful, as is keeping the individual occupied. If possible, sufferers should stay in familiar surroundings with day-care and short-stay institutional facilities a useful way of maintaining them at home for as long as possible.

TRANQUILLISERS can help control di?cult behaviour and sleeplessness but should be used with care. Recently drugs such as DONEPEZIL and RIVASTIGMINE, which retard the breakdown of ACETYLCHOLINE, may check

– but not cure – this distressing condition. About 40 per cent of those with DEMENTIA improve.

Research is in progress to transplant healthy nerve cells (developed from stem cells) into the brain tissue of patients with Alzheimer’s disease with the aim of improving brain function.

The rising proportion of elderly people in the population is resulting in a rising incidence of Alzheimer’s, which is rare before the age of 60 but increases steadily thereafter so that 30 per cent of people over the age of 84 are affected.... alzheimer’s disease

Acetylcholinesterase Inhibitors

A group of drugs that are used in the treatment of mild to moderate dementia due to Alzheimer’s disease, in which there is a deficiency of the neurotransmitter acetylcholine in the brain.

Drugs such as donepezil and rivastigmine work by blocking the action of acetylcholinesterase, the enzyme in the brain responsible for the breakdown of acetylcholine.

This raises acetylcholine levels, and, in half of all patients, the drugs slow the rate of progression of dementia.

They have no effect on dementia due to other causes, such as stroke or head injury, however.

Common side effects include nausea, dizziness, and headache.

Rarely, difficulty in passing urine may occur.... acetylcholinesterase inhibitors

Alzheimer’s Disease

A progressive condition in which nerve cells in the brain degenerate and the brain shrinks. Alzheimer’s disease is the most common cause of dementia. Onset is uncommon before the age of 60.

Early onset Alzheimer’s disease, in which symptoms develop before age 60, is inherited as a dominant disorder. Late onset Alzheimer’s disease is associated with a number of genes, including 3 that

are responsible for the production of the blood protein apolipoprotein E. These genes also result in the deposition of a protein called beta amyloid in the brain. Other chemical abnormalities may include deficiency of the neurotransmitter acetylcholine.

The features of Alzheimer’s disease vary, but there are 3 broad stages. At first, the person becomes increasingly forgetful, and problems with memory may cause anxiety and depression. In the 2nd stage, loss of memory, particularly for recent events, gradually becomes more severe, and there may be disorientation as to time or place. The person’s concentration and numerical ability decline, and there is noticeable dysphasia (inability to find the right word). Anxiety increases, mood changes are unpredictable, and personality changes may occur. Finally, confusion becomes profound. There may be symptoms of psychosis, such as hallucinations and delusions. Signs of nervous system disease, such as abnormal reflexes and faecal or urinary incontinence, begin to develop.

Alzheimer’s disease is usually diagnosed from the symptoms, but tests including blood tests and CT scanning or MRI of the brain may be needed to exclude treatable causes of dementia.

The most important aspect of treatment for Alzheimer’s disease is the provision of suitable nursing and social care for sufferers and support for their relatives. Tranquillizer drugs can often improve difficult behaviour and help with sleep. Treatment with drugs such as donepezil and rivastigmine may slow the progress of the disease for a time, but side effects such as nausea and dizziness may occur.... alzheimer’s disease

Dementia

A condition characterised by a deterioration in brain function. Dementia is almost always due to Alzheimer’s disease or to cerebrovascular disease, including strokes. Cerebrovascular dis-ease is often due to narrowed or blocked arteries in the brain. Recurrent loss of blood supply to the brain usually results in deterioration that occurs gradually but in stages. A small proportion of cases of dementia in people younger than 65 have a underlying treatable cause such as head injury, brain tumour, encephalitis, or alcohol dependence.

The main symptoms of dementia are progressive memory loss, disorientation, and confusion. Sudden outbursts or embarrassing behaviour may be the first signs of the condition. Unpleasant personality traits may be magnified; families may have to endure accusations, unreasonable demands, or even assault. Paranoia, depression, and delusions may occur as the disease worsens. Irritability or anxiety gives way to indifference towards all feelings. Personal habits deteriorate, and speech becomes incoherent. Affected people may eventually need total nursing care.

Management of the most common

Alzheimer-type illness is based on the treatment of symptoms. Sedative drugs may be given for restlessness or paranoia. Drugs for dementia, for example donepezil, can slow mental decline in some people with mild to moderate Alzheimer’s disease (see acetylcholinesterase inhibitors).... dementia

Acetylcholinesterase Inhibitor

any one of a class of drugs that block the action of acetylcholinesterase (see cholinesterase), an enzyme that quickly breaks down the neurotransmitter acetylcholine. This neurotransmitter is central to the functional interconnection between nerve cells in the outer layer (cortex) of the brain; the early impairment of cognitive function found in Alzheimer’s disease is associated with a reduction in acetylcholine levels. By inhibiting acetylcholine breakdown, acetylcholinesterase inhibitors have been found helpful in slowing down the rate of cognitive decline in mild to moderate dementia; they do not halt the progress of the disease. The group includes donepezil, galantamine, and rivastigmine... acetylcholinesterase inhibitor



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