Case Study in poly-pharmacy: Dementia
Polypharmacy is the prescribing of too many unnecessary or inappropriate medicines. Medications used to treat cardiovascular conditions (mainly high blood pressure and heart disease) are the most common medications contributing to polypharmacy. In this article, I specifically deal with dementia and the often-numerous medication prescribed to control its symptoms has on a person’s health. My experience of dementia is that is has such a profound effect on both physical and mental health that few other conditions leads to polypharmacy (numerous medication prescribed) over such a short period of time.
Dementia’s impact on health
Dementia is an umbrella term used to describe various conditions which damage brain cells and lead to a loss of brain function over time. Dementia causes a progressive decline in a person’s mental functioning. It is a broad term, which describes a loss of memory, intellect, rationality, social skills and normal emotional reactions. There are more than 100 conditions that cause dementia. Dementia affects approximately one in 20 of people aged over 65 years. This rises to one in five in the 80 plus age group. A person with dementia will live for an average of four to eight years, depending on their age at diagnosis. Average life span will also be affected by gender, other medical conditions and the severity of dementia at the time of diagnosis. Dementia ranks as the fourth leading cause of death among the population aged 65 years and over. Alzheimer's disease (AD), the most common cause of dementia in Ireland, accounts for more than 50% of all cases; the second most common form is vascular dementia, which may be preventable.
A dominant condition
Certain conditions ‘dominate’ all other health issues both in the impact on daily life and in the impact on prognosis. Dementia is good example of a dominant condition; dementia makes decisions on other conditions more complex. A highly individualised approach to co-prescribing is often required in dementia, as the severity, impact and course of the illness can be so variable.
The loss of the person’s mental faculties leads to many psychological and physical conditions which can quickly lead to complex health issues and numerous prescribed medications. As dementia progresses, various conditions develop that may lead to death, such as septicaemia, pneumonia and upper respiratory infections, nutritional disorders, pressure sores, fractures, and wounds. Various psyschological issues can result from dementia including behavioural disorders, depression and anxiety disorders. For this article I will give a brief outline of the challenges in treating the cognitive and psychological issues associated with dementia.
Drugs used for cognitive impairment
Four drugs are approved for treatment of cognitive impairment in dementia of Alzheimer’s Disease (AD): donezepil, galantamine, rivastigimine and memantine. The most common side effects are nausea, vomiting, diarrhoea and anorexia. These can be a problem because many people with AD lose weight. However, tolerance to these adverse effects normally develops. Trials have demonstrated that donezepil, galantamine and rivastigimine give modest improvement in cognitive symptoms. Some studies demonstrated a beneficial effect for up to two years after starting treatment.
Of the four drugs, available memantine is the only one licensed to treat moderate severe AD. Treatment with memantine can reduce agitation in many patients as help with the cognitive (e.g. Memory) type issues. Some patients may be prescribed memantine along with a cholinesterase inhibitor (e.g. donepezil).
Antipsychotic drugs are frequently prescribed with the aim of reducing behavioural and psychological symptoms of dementia (BPSD) in older people. In the UK, studies indicate up to 20% of patients diagnosed with dementia are prescribed anti-psychotics for PBSD. The first line treatment for psychotic symptoms in dementia is atypical antipsychotic (olanzapine, risperidone). These are associated with fewer extrapyramidal effects (tremors, movement disorders) than conventional or older antipsychotics such as haloperidol. Extrapyramidal effects can include Parkinson symptoms (Tremor), dystonia (abnormal face and body movements), akathisia (restlessness) and tardive dyskinesia (rhythmic, involuntary movements of tongue, face and jaw)
Despite this high rate of use, antipsychotics have only limited benefit in treating BPSD in older people with dementia and carry risks. In 2009, antipsychotics were estimated to cause approximately 1800 deaths and 1620 cerebrovascular events in people with dementia in the UK annually for treatment of PBSD. However, clinical trial evidence in nursing home patients with dementia indicates that chronically prescribed antipsychotic drugs can be safely discontinued in many patients, with longer term follow-up suggesting a significant reduction in mortality. However, this needs to be balanced against the fact that antipsychotics can greatly improve quality of life in some dementia patients suffering with the likes of severe agitation with dementia.
Why should anti-psychotics be prioritised for review?
Patients who have dementia and who have been on antipsychotics for more than 3 months and have stable symptoms should be reviewed with a view to reducing or stopping antipsychotic medication. Antipsychotics are associated with an increased risk of falls, disorientation, cerebrovascular events (e.g. Strokes) and death.
Depression is a common with dementia. Exercise may help reduce the symptoms of depression, and clinical trials support the use of antidepressants. Newer selective serotonin reuptake inhibitors (Prozac type anti-depressants) are the preferred class, rather than the older tricyclic agents, which have troublesome side effects. Small studies have demonstrated beneficial effects with trazodone and citalopram.
Frequent review of the person’s medication is essential to prevent unnecessary prescriptions and the harm this can cause. The pharmacist has an important role in reducing risks in reducing over-prescribing, especially in older patients who can be more susceptible to adverse effects.
References upon request
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