Antipsychotics in people with dementia: frequency of use and rationale for prescribing in a UK mental health service

Adverse Drug Reactions of Acetylcholinesterase Inhibitors in Older People Living with Dementia: A Comprehensive Literature Review

The rising of global geriatric population has contributed to increased prevalence of dementia. Dementia is a neurodegenerative disease, which is characterized by progressive deterioration of cognitive functions, such as judgment, language, memory, attention and visuospatial ability. Dementia not only has profoundly devastating physical and psychological health outcomes, but it also poses a considerable healthcare expenditure and burdens. Acetylcholinesterase inhibitors (AChEIs), or so-called anti-dementia medications, have been developed to delay the progression of neurocognitive disorders and to decrease healthcare needs. AChEIs have been widely prescribed in clinical practice for the treatment of Alzheimer's disease, which account for 70% of dementia. The rising use of AChEIs results in increased adverse drug reactions (ADRs) such as cardiovascular and gastrointestinal adverse effects, resulting from overstimulation of peripheral cholinergic activity and muscarinic receptor activation. Changes in pharmacokinetics (PK), pharmacodynamics (PD) and pharmacogenetics (PGx), and occurrence of drug interactions are said to be major risk factors of ADRs of AChEIs in this population. To date, comprehensive reviews in ADRs of AChEIs have so far been scarcely studied. Therefore, we aimed to recapitulate and update the diverse aspects of AChEIs, including the mechanisms of action, characteristics and risk factors of ADRs, and preventive strategies of their ADRs. The collation of this knowledge is essential to facilitate efforts to reduce ADRs of AChEIs.

Dementia ascertainment using existing data in UK longitudinal and cohort studies: a systematic review of methodology

BACKGROUND

Studies investigating the risk factors for or causation of dementia must consider subjects prior to disease onset. To overcome the limitations of prospective studies and self-reported recall of information, the use of existing data is key. This review provides a narrative account of dementia ascertainment methods using sources of existing data.

METHODS

The literature search was performed using: MEDLINE, EMBASE, PsychInfo and Web of Science. Included articles reported a UK-based study of dementia in which cases were ascertained using existing data. Existing data included that which was routinely collected and that which was collected for previous research. After removing duplicates, abstracts were screened and the remaining articles were included for full-text review. A quality tool was used to evaluate the description of the ascertainment methodology.

RESULTS

Of the 3545 abstracts screened, 360 articles were selected for full-text review. 47 articles were included for final consideration. Data sources for ascertainment included: death records, national datasets, research databases and hospital records among others. 36 articles used existing data alone for ascertainment, of which 27 used only a single data source. The most frequently used source was a research database. Quality scores ranged from 7/16 to 16/16. Quality scores were better for articles with dementia ascertainment as an outcome. Some papers performed validation studies of dementia ascertainment and most indicated that observed rates of dementia were lower than expected.

CONCLUSIONS

We identified a lack of consistency in dementia ascertainment methodology using existing data. With no data source identified as a "gold-standard", we suggest the use of multiple sources. Where possible, studies should access records with evidence to confirm the diagnosis. Studies should also calculate the dementia ascertainment rate for the population being studied to enable a comparison with an expected rate.

Risk of Adverse Outcomes for Older People with Dementia Prescribed Antipsychotic Medication: A Population Based e-Cohort Study

INTRODUCTION

Over recent years there has been growing evidence of increased risk of mortality associated with antipsychotic use in older people with dementia. Although this concern combined with limited evidence of efficacy has informed guidelines restricting antipsychotic prescription in this population, the use of antipsycotics remains common. Many published studies only report short-term outcomes, are restricted to examining mortality and stroke risk or have other limitations. The aim of this study was to assess adverse outcomes associated with the use of antipsychotics in older people living with dementia in Wales (UK).

METHODS

This was a retrospective study of a population-based dementia cohort using the Welsh Secure Anonymised Information Linkage databank. The prior event rate ratio (PERR) was used to estimate the influence of exposure to antipsychotic medication on acute cardiac events, venous thromboembolism, stroke and hip fracture, and adjusted Cox proportional hazard models were used to compare all-cause mortality.

RESULTS

A total of 10,339 people aged ≥65 years were identified with newly diagnosed dementia. After excluding those who did not meet the inclusion criteria, 9674 people remained in the main cohort of whom 3735 were exposed to antipsychotic medication. An increased risk of a venous thromboembolic episode [PERR 1.95, 95% confidence interval (CI) 1.83-2.0], stroke (PERR 1.41, 95% CI 1.4-1.46) and hip fracture (PERR 1.62, 95% CI 1.59-1.65) was associated with antipsychotic use. However, there was no long-term increased mortality in people exposed to antipsychotics (adjusted hazard ratio 1.06, 95% CI 0.99-1.13).

CONCLUSIONS

The increase in adverse medical events supports guidelines restricting antipsychotic use in this population.

Associations between risk of mortality and atypical antipsychotic use in vascular dementia: a clinical cohort study

OBJECTIVES

People with vascular dementia (VaD) are frequently prescribed atypical antipsychotics to treat behavioural and psychological symptoms, but there is an alarming lack of evidence regarding their safety or efficacy in VaD. This study sought to identify the mortality risk associated with the most commonly prescribed atypical antipsychotics in people with VaD compared with people not exposed to these drugs.

METHODS

A clinical cohort study of 1531 people with VaD performed using anonymised versions of full electronic health records from the Clinical Record Interactive Search application at the South London and Maudsley NHS Foundation Trust. Patients were identified from 2007 to 2010, of whom 337 were exposed to quetiapine, risperidone or olanzapine. The main outcome measure was mortality.

RESULTS

Patients exposed to atypical antipsychotics were not at increased risk of mortality [hazard ratio (HR) 1.05, 95% confidence interval (CI): 0.87-1.26]. Exposure to risperidone did not result in an increased risk of mortality (HR = 0.85; 95% CI: 0.59-1.24), and patients exposed to quetiapine had a non-significant numerical increase in mortality risk (HR = 1.14; 95% CI: 0.93-1.39; p-value = 0.20) compared with untreated patients. Too few patients were exposed to olanzapine alone to provide reliable results.

CONCLUSIONS

The absence of a significant increase in mortality risk associated with atypical antipsychotics in people with VaD indicates that a clinical trial of antipsychotics focussing on the treatment of aggression and agitation in this patient group will be justified and feasible following further consideration of possible confounders, which will be critical to determine the role of antipsychotics in treatment of VaD.