Adherence, persistence and continuation with cholinesterase inhibitors in Alzheimer's disease

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.

Withdrawal or continuation of cholinesterase inhibitors or memantine or both, in people with dementia

BACKGROUND

Dementia is a progressive syndrome characterised by deterioration in memory, thinking and behaviour, and by impaired ability to perform daily activities. Two classes of drug - cholinesterase inhibitors (donepezil, galantamine and rivastigmine) and memantine - are widely licensed for dementia due to Alzheimer's disease, and rivastigmine is also licensed for Parkinson's disease dementia. These drugs are prescribed to alleviate symptoms and delay disease progression in these and sometimes in other forms of dementia. There are uncertainties about the benefits and adverse effects of these drugs in the long term and in severe dementia, about effects of withdrawal, and about the most appropriate time to discontinue treatment.

OBJECTIVES

To evaluate the effects of withdrawal or continuation of cholinesterase inhibitors or memantine, or both, in people with dementia on: cognitive, neuropsychiatric and functional outcomes, rates of institutionalisation, adverse events, dropout from trials, mortality, quality of life and carer-related outcomes.

SEARCH METHODS

We searched the Cochrane Dementia and Cognitive Improvement Group's Specialised Register up to 17 October 2020 using terms appropriate for the retrieval of studies of cholinesterase inhibitors or memantine. The Specialised Register contains records of clinical trials identified from monthly searches of a number of major healthcare databases, numerous trial registries and grey literature sources.

SELECTION CRITERIA

We included all randomised, controlled clinical trials (RCTs) which compared withdrawal of cholinesterase inhibitors or memantine, or both, with continuation of the same drug or drugs.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed citations and full-text articles for inclusion, extracted data from included trials and assessed risk of bias using the Cochrane risk of bias tool. Where trials were sufficiently similar, we pooled data for outcomes in the short term (up to 2 months after randomisation), medium term (3-11 months) and long term (12 months or more). We assessed the overall certainty of the evidence for each outcome using GRADE methods.

MAIN RESULTS

We included six trials investigating cholinesterase inhibitor withdrawal, and one trial investigating withdrawal of either donepezil or memantine. No trials assessed withdrawal of memantine only. Drugs were withdrawn abruptly in five trials and stepwise in two trials. All participants had dementia due to Alzheimer's disease, with severities ranging from mild to very severe, and were taking cholinesterase inhibitors without known adverse effects at baseline. The included trials randomised 759 participants to treatment groups relevant to this review. Study duration ranged from 6 weeks to 12 months. There were too few included studies to allow planned subgroup analyses. We considered some studies to be at unclear or high risk of selection, performance, detection, attrition or reporting bias. Compared to continuing cholinesterase inhibitors, discontinuing treatment may be associated with worse cognitive function in the short term (standardised mean difference (SMD) -0.42, 95% confidence interval (CI) -0.64 to -0.21; 4 studies; low certainty), but the effect in the medium term is very uncertain (SMD -0.40, 95% CI -0.87 to 0.07; 3 studies; very low certainty). In a sensitivity analysis omitting data from a study which only included participants who had shown a relatively poor prior response to donepezil, inconsistency was reduced and we found that cognitive function may be worse in the discontinuation group in the medium term (SMD -0.62; 95% CI -0.94 to -0.31). Data from one longer-term study suggest that discontinuing a cholinesterase inhibitor is probably associated with worse cognitive function at 12 months (mean difference (MD) -2.09 Standardised Mini-Mental State Examination (SMMSE) points, 95% CI -3.43 to -0.75; moderate certainty). Discontinuation may make little or no difference to functional status in the short term (SMD -0.25, 95% CI -0.54 to 0.04; 2 studies; low certainty), and its effect in the medium term is uncertain (SMD -0.38, 95% CI -0.74 to -0.01; 2 studies; very low certainty). After 12 months, discontinuing a cholinesterase inhibitor probably results in greater functional impairment than continuing treatment (MD -3.38 Bristol Activities of Daily Living Scale (BADLS) points, 95% CI -6.67 to -0.10; one study; moderate certainty). Discontinuation may be associated with a worsening of neuropsychiatric symptoms over the short term and medium term, although we cannot exclude a minimal effect (SMD - 0.48, 95% CI -0.82 to -0.13; 2 studies; low certainty; and SMD -0.27, 95% CI -0.47 to -0.08; 3 studies; low certainty, respectively). Data from one study suggest that discontinuing a cholinesterase inhibitor may result in little to no change in neuropsychiatric status at 12 months (MD -0.87 Neuropsychiatric Inventory (NPI) points; 95% CI -8.42 to 6.68; moderate certainty). We found no clear evidence of an effect of discontinuation on dropout due to lack of medication efficacy or deterioration in overall medical condition (odds ratio (OR) 1.53, 95% CI 0.84 to 2.76; 4 studies; low certainty), on number of adverse events (OR 0.85, 95% CI 0.57 to 1.27; 4 studies; low certainty) or serious adverse events (OR 0.80, 95% CI 0.46 to 1.39; 4 studies; low certainty), and on mortality (OR 0.75, 95% CI 0.36 to 1.55; 5 studies; low certainty). Institutionalisation was reported in one trial, but it was not possible to extract data for the groups relevant to this review.

AUTHORS' CONCLUSIONS

This review suggests that discontinuing cholinesterase inhibitors may result in worse cognitive, neuropsychiatric and functional status than continuing treatment, although this is supported by limited evidence, almost all of low or very low certainty. As all participants had dementia due to Alzheimer's disease, our findings are not transferable to other dementia types. We were unable to determine whether the effects of discontinuing cholinesterase inhibitors differed with baseline dementia severity. There is currently no evidence to guide decisions about discontinuing memantine. There is a need for further well-designed RCTs, across a range of dementia severities and settings. We are aware of two ongoing registered trials. In making decisions about discontinuing these drugs, clinicians should exercise caution, considering the evidence from existing trials along with other factors important to patients and their carers.

Compliance and persistence with Alzheimer's disease treatment: a retrospective analysis of multiregional hospital databases in Thailand

Aims: Due to the lack of studies evaluating compliance or persistence with Alzheimer's Disease (AD) treatment outside High-Income Countries (HICs), this study aimed to assess compliance, persistence, and factors associated with non-compliance and non-persistence by utilizing existing "real-world" information from multiregional hospital databases in Thailand.Materials and methods: Study subjects were retrospectively identified from databases of five hospitals located in different regions across Thailand. AD patients aged ≥60 years who were newly-prescribed with donepezil, galantamine, rivastigmine, or memantine between 2013 and 2017 were eligible for analysis. The Medication Possession Ratio (MPR) was used as a proxy for compliance, while the Kaplan-Meier survival analysis was employed to estimate persistence. Logistic and Cox regressions were used to assess determinants of non-compliance and non-persistence, adjusted for age and gender.Results: Among 698 eligible patients, mean (SD) MPR was 0.83 (0.25), with 70.3% of the patients compliant to the treatment (having MPR ≥ 0.80). Half of the patients discontinued their treatment (having a treatment gap >30 days) within 177 days with a 1-year persistence probability of 21.1%. The patients treated in the university-affiliated hospital were more likely to be both non-compliant (OR = 1.71; 95% CI = 1.21-2.42) and non-persistent (HR = 1.33; 95% CI = 1.12-1.58). In addition, non-compliance was higher for those prescribed with single AD treatment (OR = 2.52; 95% CI = 1.35-4.69), while non-persistence was higher for those unable to reimburse for AD treatment (HR = 1.34; 95% CI = 1.11-1.62).Limitations: By using retrospective databases, a difficulty in validating whether the medications are actually taken after being refilled may over-estimate the levels of compliance and persistence. Meanwhile, possible random coding errors may under-estimate the strength of association findings.Conclusions: This study reveals the situation of compliance and persistence on AD treatment for the first time outside HICs. The determinants of non-compliance and non-persistence underline key areas for improvement.

Prevalence and Incidence of Statin Use and 3-Year Adherence and Discontinuation Rates Among Older Adults With Dementia

OBJECTIVE

To examine the patterns of statin use and determine the 3-year adherence and discontinuation rates among a cohort of Australians aged ≥65 years with dementia.

METHODS

The yearly prevalence and incidence of statin use were compared via Poisson regression modeling using 2007 as the reference year. People with dementia were identified according to dispensing of antidementia medications. A cohort of 589 new statin users was followed longitudinally. Adherence was estimated via the proportion of days covered (PDC). Discontinuation was defined as ≥90 days without statin coverage.

RESULTS

The annual prevalence of statin use among older Australians with dementia increased from 20.6% in 2007 to 31.7% in 2016 (aged-sex adjusted rate ratio: 1.51, 95% confidence interval: 1.35-1.69). Among the new users, the proportion adherent (PDC ≥ 0.80) decreased from 60.3% at 6 months to 31.0% at 3 years. During the 3-year follow-up, 58.7% discontinued their statin.

CONCLUSIONS

Despite increased use of statins among older Australians with dementia, adherence is low and discontinuation is high, which may point to intentional cessation.

Medication Adherence in Older Patients With Dementia: A Systematic Literature Review

Background:

Older patients with dementia are often unable to take their medications as prescribed due to cognitive and physical impairment.

Objectives:

To review the evidence on medication adherence in older patients with dementia in terms of the level of adherence, outcomes, contributing factors, and available interventions.

Methods:

A systematic literature review was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Searched databases included CINAHL, Cochrane Library, DARE, MEDLINE, and PubMed.

Results:

Eighteen studies reported levels of medication adherence or discontinuation and related factors. Medication adherence ranged from 17% to 42%, and medication discontinuation before the end of treatment ranged from 37% to 80%. Nonadherence was associated with an increased risk of hospitalization or death, while increasing age, choice of medication, use of concomitant medications, and medicines’ costs were reported to decrease medication adherence. Telehealth home monitoring and treatment modification were the only interventions reported in the literature to improve medication adherence in this population.

Conclusion:

Older patients with dementia have a low level of medication adherence. Future research should focus on the development and implementation of interventions to help older patients with dementia and their caregivers make better use of medications.

Temporal trends for donepezil utilization among older people

To examine and characterize overall donepezil and concomitant utilization with β-blockers, yearly, in older New Zealanders. Deidentified data from the Pharmaceutical claims database and the National Minimum Dataset were obtained for 2011 to 2013 from the Ministry of Health. Population-level data were extracted for donepezil and β-blockers utilization, measured by defined daily dose (DDD) per thousand older people per day (TOPD). Donepezil utilization increased from 5.2 to 8.2 DDD/TOPD between 2011 and 2013. In 2011, the number of prevalent users was 4634, the mean age was 79.4±6.6 years and 57.5% were women. Highest use by age for donepezil was in those aged 85 years or older (2.3 DDD/TOPD), followed by those aged 80-84 years (2.2 DDD/TOPD). The mean utilization volumes were significantly lower for donepezil 5 mg (Student t-test=9.86; P<0.05) and 10 mg (10.90; P<0.05) in the 65- to 69-year age group compared with the 80- to 84-year age group, whereas the proportion of concomitant utilization of donepezil with β-blockers decreased (17.9% to 5.1%). Donepezil utilization in DDD/TOPD increased by three-fifths between 2011 and 2013. Prescribers appear to be aware of the potential risk of bradycardia with the concomitant use of donepezil and β-blockers.

Donepezil Adherence, Persistence and Time to First Discontinuation in a Three-Year Follow-Up of Older People

Background

Donepezil is indicated for the management of mild to moderate dementia, particularly in Alzheimer's disease. Several studies have described low adherence rates with donepezil.

Aim

To examine and measure donepezil adherence, persistence and time to first discontinuation in older New Zealanders.

Methods

An inception cohort of 1,999 new users of donepezil, aged 65 years or older, were identified from the Pharmaceutical Collections and National Minimum Dataset from 1 November 2010 to 31 December 2013. Kaplan-Meier curves and Cox regression analysis were used to estimate the cumulative probability and risk of time to first discontinuation of donepezil therapy.

Results

The mean age of the cohort was 79.5 ± 6.4 years and included 42.7% females. Adherence was high (89.0%), while the proportion of donepezil dispensings (81.0-32.5%) declined between 6 and 36 months. Persistence between the 1st and 6th dispensing visit decreased by 19.0%, and 11.0% of the total cohort had a gap of 31 days or more. The adjusted risk of time to first discontinuation in the non-adherent group was 2.2 times (95% CI 1.9-2.6) that of the adherent group.

Conclusions

The non-adherent new donepezil users, on average, discontinued faster than the adherent group. Time to first discontinuation in this study was higher compared to discontinuation rates observed in clinical trials.

Persistence and adherence with dementia pharmacotherapy: relevance of patient, provider, and system factors

This paper provides a comprehensive review of studies examining adherence and (or) persistence with dementia pharmacotherapy during the past decade, including a summary of the key patient-, drug-, system-, and provider-level factors associated with these measures. Estimates of adherence and 1-year persistence to these drugs have ranged from 34% to 94% and 35% to 60%, respectively. Though many studies reported nonsignificant associations, there are data suggesting that patient age, sex, ethnoracial background, socioeconomic status, and region-specific reimbursement criteria, as well as the extent and quality of interactions among patients, caregivers, and providers, may influence persistence with pharmacotherapy. As many studies relied on administrative data, limited information was available regarding the relevance of patient's cognitive and functional status or the importance of caregiver involvement or assistive devices to adherence or persistence.

A 2-year prospective cohort study of antidementia drug non-persistency in mild-to-moderate Alzheimer's disease in Europe : predictors of discontinuation and switch in the ICTUS study

BACKGROUND

There is no consensus on when and how to discontinue cholinesterase inhibitors (ChEI). Predictors of non-persistency of antidementia drugs have been poorly investigated, mostly during short-term periods and using administrative data.

OBJECTIVE

The aim of this study was to investigate the incidence and predictors of ChEI switch and discontinuation among subjects with ascertained Alzheimer's disease (AD).

METHODS

A total of 557 community-dwelling, mild-to-moderate AD subjects initiating ChEIs in 29 European clinic centres were assessed twice-yearly for 2 years. Antidementia drug exposure was recorded through a physician-administered structured questionnaire to document any change in drug therapy (start and stop dates, reasons). Discontinuation was defined as >35 days without any antidementia drug. Switch was defined as a change for any antidementia drug strategy within 35 days after ChEI cessation. Two separate time-dependent multivariate Cox survival analyses were conducted to identify predictors of discontinuation and switch.

RESULTS

The incidences of discontinuation and switch were 9.65 and 12.47/100 person-years, respectively. Behavioural disturbances, low body mass index, falls, decline in Mini-Mental State Examination (MMSE) score, and AD-related hospitalization predicted discontinuation. MMSE score, decline in activities of daily living score, aberrant motor behaviour, shorter AD duration and higher nurse resource use predicted a switch. An ineffective ChEI dose and clinic specialty predicted both outcomes. Sensitivity analyses using a 60-day cut-off provided stable results.

CONCLUSION

Several predictors were identified: adverse drug events and their predisposing factors, perceived loss of efficacy or disease progression on cognitive or functional scales, behavioural disturbances, hospitalization and professional practices. The latter implies a need for harmonization in AD drug prescription practice.

Medication adherence survey of drugs useful in prevention of dementia of Alzheimer's type among Indian patients

BACKGROUND

Good medication adherence is the cornerstone of therapeutic success. Alzheimer's disease (AD) is the most common type of dementia and most patients are old and on multiple drugs, and good compliance therefore is even more important in this population. Dementia of Alzheimer's type (DAT) at present is yet to find a cure. Anticholinesterases and N-methyl-D-aspartate blockers are specific anti-AD therapies available. Hypertension, diabetes, and dyslipidemia can contribute to cognitive worsening. Keeping hypertension, diabetes, and dyslipidemia in control can therefore possibly prevent further cognitive decline.

METHODS

Patients with subjective memory complaints (n = 75) were chosen randomly. Upon thorough neurological diagnostic work up for dementia, those with mild cognitive impairment/questionable dementia (Clinical Dementia Rating = 0.5) or those with AD were recruited in this study (n = 67). Those with hypertension, diabetes, and deranged lipid profile were further interviewed if they were able to take medicines regularly or not. An attempt was made to know causes of non-compliance.

RESULTS

Forty-one percent of patients were not taking the drugs that have potential to prevent cardiovascular complications or ability to slow down cognitive decline in AD on regular basis. The lack of awareness, ignorance, medicines being "too expensive," and the pressure of taking medicines regularly were cited as the reasons for non-compliance. Being illiterate and having low education contributed majorly to poor compliance in this study.

CONCLUSION

Compliance to drugs that have potential or real ability to slow down cognitive decline is low in elderly people with DAT.