Factors associated with serious adverse reactions to cholinesterase inhibitors: a study of spontaneous reporting

Exploring the impact of co-exposure timing on drug-drug interactions in signal detection through spontaneous reporting system databases: a scoping review

INTRODUCTION

Drug-drug interactions (DDIs) are defined as the pharmacological effects produced by the concomitant administration of two or more drugs. To minimize false positive signals and ensure their validity when analyzing Spontaneous Reporting System (SRS) databases, it has been suggested to incorporate key pharmacological principles, such as temporal plausibility.

AREAS COVERED

The scoping review of the literature was completed using MEDLINE from inception to March 2023. Included studies had to provide detailed methods for identifying DDIs in SRS databases. Any methodological approach and adverse event were accepted. Descriptive analyzes were excluded as we focused on automatic signal detection methods. The result is an overview of all the available methods for DDI signal detection in SRS databases, with a specific focus on the evaluation of the co-exposure time of the interacting drugs. It is worth noting that only a limited number of studies (n = 3) have attempted to address the issue of overlapping drug administration times.

EXPERT OPINION

Current guidelines for signal validation focus on factors like the number of reports and temporal association, but they lack guidance on addressing overlapping drug administration times, highlighting a need for further research and method development.

Therapeutic dilemmas: cognitive enhancers and risk of falling in older adults-a clinical review

PURPOSE

Cognitive enhancers are the primary pharmacological therapy prescribed to those with dementia, comprising of memantine and the acetylcholinesterase inhibitors (AChEIs). The long-term cognitive and behavioural benefits of these medications, as well as their potential contribution to falls is currently debated, with recent Delphi studies being unable to reach consensus on whether these medications should be deprescribed. In this narrative clinical review, as part of a series on deprescribing in people at risk of falls, we explore the potential falls-related side effects experienced in people taking cognitive enhancers, alongside situations where deprescribing may be appropriate.

METHODS

We undertook a literature search of PubMed and Google Scholar, using terms capturing falls and cognitive enhancers, as well as consulting the British National Formulary and published Summary of Medicinal Product Characteristics. These searches informed the subsequent clinical review.

RESULTS

Cognitive enhancers should be subject to regular review, including confirmation of appropriate treatment indication, and occurrence of side effects in the context of falls. AChEIs, in particular, are associated with a broad range of side effects that can contribute to increased falls risk. These include bradycardia, syncope and neuromuscular effects. Where these have been identified, deprescribing should be considered, as well as alternative treatment options. Deprescribing studies have shown mixed results, likely due to considerable methodological heterogeneity. Several suggested guidelines exist to aid deprescribing decisions, many of which are highlighted in this review.

CONCLUSIONS

The use of cognitive enhancers should be regularly reviewed and decisions to deprescribe made on a case-by-case basis, considering both the risks and benefits of stopping these medications.

Recent Progress in Research on Mechanisms of Action of Natural Products against Alzheimer's Disease: Dietary Plant Polyphenols

Alzheimer's disease (AD) is an incurable degenerative disease of the central nervous system and the most common type of dementia in the elderly. Despite years of extensive research efforts, our understanding of the etiology and pathogenesis of AD is still highly limited. Nevertheless, several hypotheses related to risk factors for AD have been proposed. Moreover, plant-derived dietary polyphenols were also shown to exert protective effects against neurodegenerative diseases such as AD. In this review, we summarize the regulatory effects of the most well-known plant-derived dietary polyphenols on several AD-related molecular mechanisms, such as amelioration of oxidative stress injury, inhibition of aberrant glial cell activation to alleviate neuroinflammation, inhibition of the generation and promotion of the clearance of toxic amyloid-β (Aβ) plaques, inhibition of cholinesterase enzyme activity, and increase in acetylcholine levels in the brain. We also discuss the issue of bioavailability and the potential for improvement in this regard. This review is expected to encourage further research on the role of natural dietary plant polyphenols in the treatment of AD.

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.

Identification of metabolites of MDR-1339, an inhibitor of β-amyloid protein aggregation, and kinetic characterization of the major metabolites in rats

We previously reported that MDR-1339, an inhibitor of β-amyloid protein aggregation, was likely to be eliminated by biotransformation in rats. The objective of this study was to determine the chemical identity of metabolites derived from this aggregate inhibitor and to characterize the kinetics of formation of these metabolites in rats. Using high performance liquid chromatography coupled with mass spectrometry with a hybrid triple quadrupole-linear ion trap, 7 metabolites and 1 potential metabolic intermediate were identified in RLM incubations containing MDR-1339. In addition to these, 3 glucuronide metabolites were detected in urine samples from rats receiving a 10 mg/kg oral dose of MDR-1339. When the kinetics of the formation of two major metabolites, M1 and M2, were analyzed assuming simple Michaelis-Menten kinetics, the V_max and K_m values were found to be 0.459 ± 0.0196 nmol/min/mg protein and 28.3 ± 3.07 μM for M1, and 0.101 ± 0.00537 nmol/min/mg protein and 14.7 ± 2.37 μM for M2, respectively. When chemically synthesized M1 and M2 were individually administered to rats intravenously at the dose of 5 mg/kg respectively, the volume of distribution and elimination clearance were determined to be 4590 ± 709 mL/kg and 68.4 ± 5.60 mL/min/kg for M1 and 15300 ± 8110 mL/kg and 98.0 ± 19.5 mL/min/kg for M2, respectively. When MDR-1339 was intravenously administered to rats at a dose of 5 mg/kg, the parent drug and M1 were readily detected for periods of up to 6 h after the administration, but M2 was observed only from 2 to 4 h. A standard moment analysis indicates that the formation clearance of M1 is 6.01 mL/min/kg, suggesting that 19.7% of the MDR-1339 dose was eliminated in rats. These observations indicate that the hepatic biotransformation of MDR-1339 results in the formation of at least 10 metabolites and that M1 is the major metabolite derived from this aggregation inhibitor in rats.

Potential drug-drug interactions in Alzheimer patients with behavioral symptoms

The use of multi drug regimens among the elderly population has increased tremendously over the last decade although the benefits of medications are always accompanied by potential harm, even when prescribed at recommended doses. The elderly populations are particularly at an increased risk of adverse drug reactions considering comorbidity, poly-therapy, physiological changes affecting the pharmacokinetics and pharmacodynamics of many drugs and, in some cases, poor compliance due to cognitive impairment and/or depression. In this setting, drug–drug interaction may represent a serious and even life-threatening clinical condition. Moreover, the inability to distinguish drug-induced symptoms from a definitive medical diagnosis often results in addition of yet another drug to treat the symptoms, which in turn increases drug–drug interactions. Cognitive enhancers, including acetylcholinesterase inhibitors and memantine, are the most widely prescribed agents for Alzheimer’s disease (AD) patients. Behavioral and psychological symptoms of dementia, including psychotic symptoms and behavioral disorders, represent noncognitive disturbances frequently observed in AD patients. Antipsychotic drugs are at high risk of adverse events, even at modest doses, and may interfere with the progression of cognitive impairment and interact with several drugs including anti-arrhythmics and acetylcholinesterase inhibitors. Other medications often used in AD patients are represented by anxiolytic, like benzodiazepine, or antidepressant agents. These agents also might interfere with other concomitant drugs through both pharmacokinetic and pharmacodynamic mechanisms. In this review we focus on the most frequent drug–drug interactions, potentially harmful, in AD patients with behavioral symptoms considering both physiological and pathological changes in AD patients, and potential pharmacodynamic/pharmacokinetic drug interaction mechanisms.

Adverse Drug Reactions Reported With Cholinesterase Inhibitors

Background: No worldwide pharmacovigilance study evaluating the spectrum of adverse drug reactions (ADRs) induced by cholinesterase inhibitors (ChEI) in Alzheimer’s disease has been conducted since their emergence on the market. Objective: To describe ChEI related ADRs in Alzheimer’s disease (donepezil, rivastigmine, and galantamine) and characterize their seriousness as reported by national pharmacovigilance systems to VigiBase, a World Health Organization International Drug Monitoring Program database, between 1998 and 2013. Methods: All ChEI related reports, submitted to VigiBase between 1998 and 2013 from the five continents were extracted. Analyses were carried out for general, serious, and nonserious ADRs. Results: A total of 18 955 reports (43 753 ADRs) from 58 countries were reported: 60.1% in women; mean age 77.4 ± 9.1 years. Most reports originated from Europe (47.6%) and North America (40.4%). Rivastigmine and donepezil were involved in most reports (41.4% each). The most frequently reported ADRs were neuropsychiatric (31.4%), gastrointestinal (15.9%), general (11.9%), and cardiovascular (11.7%) disorders. During the 2006-2013 period, serious ADRs remained more often reported than nonserious ones; the most serious were neuropsychiatric (34.0%), general (14.0%), cardiovascular (12.1%), and gastrointestinal (11.6%) disorders. Medication errors were reported in 2.0% of serious cases. Death occurred in 2.3% of the reports. Conclusions: This international pharmacovigilance study highlights the ADR pattern induced by ChEIs. Neuropsychiatric events were the most frequently reported ADRs. Serious cardiovascular events were frequently reported, suggesting that their significance has probably been previously underestimated. Given the frailty of the patients and the frequent comedications, caution is advised before introducing a ChEI.

Dihydroquinoline Carbamate Derivatives as "Bio-oxidizable" Prodrugs for Brain Delivery of Acetylcholinesterase Inhibitors: [¹¹C] Radiosynthesis and Biological Evaluation

With the aim of improving the efficiency of marketed acetylcholinesterase (AChE) inhibitors in the symptomatic treatment of Alzheimer's disease, plagued by adverse effects arising from peripheral cholinergic activation, this work reports a biological evaluation of new central AChE inhibitors based on an original "bio-oxidizable" prodrug strategy. After peripheral injection of the prodrug 1a [IC50 > 1 mM (hAChE)] in mice, monitoring markers of central and peripheral cholinergic activation provided in vivo proof-of-concept for brain delivery of the drug 2a [IC50 = 20 nM (hAChE)] through central redox activation of 1a. Interestingly, peripheral cholinergic activation has been shown to be limited in time, likely due to the presence of a permanent positive charge in 2a promoting rapid elimination of the AChE inhibitor from the circulation of mice. To support these assumptions, the radiosynthesis with carbon-11 of prodrug 1a was developed for additional ex vivo studies in rats. Whole-body biodistribution of radioactivity revealed high accumulation in excretory organs along with moderate but rapid brain uptake. Radio-HPLC analyses of brain samples confirm rapid CNS penetration of [(11)C]1a, while identification of [(11)C]2a and [(11)C]3a both accounts for central redox activation of 1a and pseudoirreversible inhibition of AChE, respectively. Finally, Caco-2 permeability assays predicted metabolite 3a as a substrate for efflux transporters (P-gp inter alia), suggesting that metabolite 3a might possibly be actively transported out of the brain. Overall, a large body of evidence from in vivo and ex vivo studies on small animals has been collected to validate this "bio-oxidizable" prodrug approach, emerging as a very promising strategy in the rational design of selective central AChE inhibitors.

Adverse drug reactions in patients with Alzheimer's disease and related dementia in France: a national multicentre cross-sectional study

PURPOSE

To assess the prevalence of adverse drug reactions (ADRs) occurring in patients with Alzheimer's disease (AD) or other dementia in France.

METHODS

A cross-sectional multicentre study was conducted by the French network of the 31 regional pharmacovigilance centres on a given day. The subjects were selected by random draw to be a representative sample of French patients with dementia: consultations of dementia clinics, nursing-homes, acute and long care geriatric units, rehabilitation care geriatric units. The staff of each medical structure together with that of the pharmacovigilance centre defined a day for including the patients. Socio-demographic data, history, ADR and drugs given were registered.

RESULTS

There were 1332 subjects included, 51.1% living at home, 48.8% in institutions, aged 82.0 ± 8.0 years (46-108); 61.3% suffered from AD. Mean number of drugs was 6.3 ± 3.1. Anti-dementia drugs were given to 66.4% subjects. ADR prevalence was 5.0% (95% CI: 3.9-6.2) without a significant difference between at home and institutionalized patients. ADR consisted of gastro-intestinal (23.2%), central nervous system (17.4%) and psychiatric disorders (8.7%). Of the ADR, 31.9% were serious, and 47.8% preventable. The drugs most often involved were anti-dementia (28.9%), cardio-vascular (28.9%) and psychotropic drugs (26.4%, anxiolytics, hypnotics, antidepressants, neuroleptics).

CONCLUSION

This national scale study showed that iatrogenesis in patients with AD and related dementia can at times be serious and preventable. Therefore, special attention is required when prescribing psychotropic and anti-dementia drugs, as they are frequently used and induce half of the ADR in this population.

Use of rivastigmine or galantamine and risk of adverse cardiac events: a database study from the Netherlands

BACKGROUND

Two cholinesterase inhibitors (ChEIs), rivastigmine and galantamine, are used to treat Alzheimer disease in the Netherlands. Several adverse cardiac events have been reported for these medications.

OBJECTIVE

We aimed to assess if the use of ChEIs increased the risk of cardiac events in the Netherlands.

METHODS

A cohort crossover study of the PHARMO Record Linking System database included patients who initiated ChEIs at age 50 years or older, had at least 1 dispensing of a ChEI drug between 1998 and 2008, a 1-year history in PHARMO, and 1 subsequent dispensing of any medication. Two outcomes were assessed: a first hospitalization for syncope or atrioventricular block. Poisson and Cox regression were used to calculate incidence densities and hazard ratios for cardiac events during periods with ChEI use, compared with periods without ChEI use.

RESULTS

During the complete observation period of 8.9 years (interquartile range 6.7 to 10.2) there were 132 first hospitalizations for atrioventricular block and 17 first hospitalizations for syncope among 3358 patients. The adjusted incidence densities were significantly increased during ChEI exposure for syncope and atrioventricular block, when compared with the background incidence densities in the roughly 5 years before the last year before ChEI initiation. However, when exposed periods were compared with the unexposed periods 1 year before ChEI initiation and times after exposure, the adjusted hazard ratios remained increased for syncope and atrioventricular block, but increases were not significant anymore.

CONCLUSIONS

Exposure to ChEIs might increase the risk of adverse cardiac events, but small numbers of cases limit conclusions about the risk in this population and research on larger study samples is needed.

Use of Anticholinergic Drugs and Cholinesterase Inhibitors and Their Association with Psychological Well-Being Among Frail Older Adults in Residential Care Facilities

Background

Drugs with anticholinergic properties have harmful effects among frail older people and they may antagonize the effects of cholinesterase inhibitors (ChEIs). However, their association with psychological well-being has not been studied.

Objective:

To determine (1) the prevalence of the use of anticholinergic drugs, ChEIs, or their combination among older adults in residential care facilities and their association with psychological well-being, and (2) the association of anticholinergic drugs with an individual's psychological well-being.

Methods:

In 2007, all older adults (N = 1475) living in residential care facilities in the cities of Helsinki and Espoo, Finland, were assessed in a cross-sectional study. A trained nurse retrieved data on demographic factors, regularly administered medications, and diagnoses from medical charts. Psychological well-being was assessed using 6 questions concerning life satisfaction, zest for life, plans for the future, feeling needed, and feeling depressed or lonely, and a psychological well-being score was created (range 0-1).

Results:

Residents taking anticholinergic drugs (n = 613) were significantly younger, used more drugs, and were more often on ChEIs compared with nonusers (n = 862). There was no significant difference in Charlson comorbidity index, stage of cognition, or dependence on activities of daily living between the users or nonusers of anticholinergic drugs. The anticholinergic drug users had significantly lower psychological well-being scores compared with the nonusers. Of the participants, 10.7% used ChEIs and anticholinergic drugs concomitantly. In logistic regression analysis where age, sex, comorbidities, and use of ChEIs were used as covariates, lower psychological well-being was associated with the use of anticholinergic drugs (OR 1.40; 95% CI 1.00 to 1.94; p = 0.048).

Conclusions:

Concomitant use of anticholinergic drugs and ChEIs is common among older adults. The use of anticholinergic drugs is associated with poor psychological well-being.