Cardiovascular effects and risk of syncope related to donepezil in patients with Alzheimer's disease

Effects of Cholinesterase Inhibitor Medication on QTc Interval in Memory Clinic Patients

BACKGROUND

Cholinesterase inhibitors (ChEIs)-donepezil, rivastigmine, and galantamine-are beneficial in treating Alzheimer disease (AD). However, due to their impact on extra-cerebral acetylcholine signaling, concerns about cardiac adverse effects, including QT interval prolongation, persist. Despite this, evidence-based guidelines for electrocardiogram (ECG) monitoring during ChEI treatment are lacking, and prior studies on ChEIs and corrected QT intervals (QTc) yield inconsistent findings.

OBJECTIVE

This study aimed to investigate the association between ChEI use and changes in QTc intervals among older adults.

METHODS

We collected retrospective data from first-time visitors to the geriatric memory clinic of Turku City Hospital in 2017 and 2019. We included patients who were newly prescribed ChEIs and had ECG data available (n = 126, mean age 81.1 years, 56.3% female). QTc prolongation was defined as ≥460 ms in females and ≥450 ms in men. Paired t tests compared QTc means before and during ChEI use, and McNemar tests analyzed changes in the proportion of prolonged QTc.

RESULTS

Mean ± SD QTc (ms) before versus during ChEI use was: 420.8 ± 24.0 versus 423.9 ± 28.0 (P = .13) for donepezil; 416.0 ± 20.4 versus 416.5 ± 26.1 (P = .92) for galantamine; 416.1 ± 22.3 versus 409.6 ± 20.1 (P = .30) for rivastigmine; and 419.7 ± 23.4 versus 421.5 ± 27.3 (P = .34) for all ChEIs. Prolonged QTc occurred in 7.9% of patients before versus 12.7% during ChEI use (P = .21).

CONCLUSION AND RELEVANCE

We found no statistically significant association between ChEI use and QTc interval prolongation or an increased proportion of pathological QTc values during ChEI treatment. Larger studies are warranted to establish evidence-based recommendations on ECG monitoring during ChEI medication.

Acetylcholine-loaded nanoparticles protect against doxorubicin-induced toxicity inin vitrocardiac spheroids

Doxorubicin (DOX) is widely used in chemotherapy, yet it significantly contributes to heart failure-associated death. Acetylcholine (ACh) is cardioprotective by enhancing heart rate variability and reducing mitochondrial dysfunction and inflammation. Nonetheless, the protective role of ACh in countering DOX-induced cardiotoxicity (DIC) remains underexplored as current approaches to increasing ACh levels are invasive and unsafe for patients. In this study, we explore the protective effects of ACh against DIC through three distinct ACh administration strategies: (i) freely-suspended 100µM ACh; (ii) ACh-producing cholinergic neurons (CNs); or (iii) ACh-loaded nanoparticles (ACh-NPs). These are tested inin vitrocardiac spheroids (CSs), which have previously been shown to approximate the complex DIC. We assess ACh's protective effects by measuring the toxicity ratio (cell death/viability), contractile activity, gene expression changes via qPCR and nitric oxide (NO) signaling. Our findings show that ACh effectively attenuates DOX-induced cell death and contractile dysfunction. ACh also counteracts the DOX-induced downregulation of genes controlling myocardial fibrosis, endothelial and cardiomyocyte dysfunction, and autonomic dysregulation. ACh cardioprotection against DOX is dependent on NO signaling in endothelial cells but not in cardiac myocytes or fibroblasts. Altogether, this study shows for the first time that elevating ACh levels showed a promising therapeutic approach for preventing DIC.

Protective role of acetylcholine and the cholinergic system in the injured heart

This review explores the roles of the cholinergic system in the heart, comprising the neuronal and non-neuronal cholinergic systems. Both systems are essential for maintaining cardiac homeostasis by regulating the release of acetylcholine (ACh). A reduction in ACh release is associated with the early onset of cardiovascular diseases (CVDs), and increasing evidence supports the protective roles of ACh against CVD. We address the challenges and limitations of current strategies to elevate ACh levels, including vagus nerve stimulation and pharmacological interventions such as cholinesterase inhibitors. Additionally, we introduce alternative strategies to increase ACh in the heart, such as stem cell therapy, gene therapy, microRNAs, and nanoparticle drug delivery methods. These findings offer new insights into advanced treatments for regenerating the injured human heart.

QT interval prolongation and Torsades de Pointes with donepezil, rivastigmine and galantamine

Background

Acetylcholinesterase inhibitors (AChEis) including donepezil, galantamine and rivastigmine are used to treat Alzheimer's disease (AD). This study aimed to evaluate evidence from the case report literature for an association between these agents and risk of QT interval prolongation and Torsades de Pointes (TdP) arrhythmia.

Methods

Published literature was mined with predetermined MeSH terms for each of donepezil, galantamine and rivastigmine, to identify cases of QT interval prolongation and TdP. Case reports were analysed using causality scales and a QT interval nomogram.

Results

A total of 13 case reports were found (10 for donepezil, 2 for galantamine and 1 for rivastigmine) with rate corrected QT interval (QT_c) prolongation. Five cases with donepezil exhibited TdP. TdP was not reported in the cases with galantamine and rivastigmine. The use of a QT heart rate nomogram highlighted risk with donepezil compared with the other two drugs and the application of the Naranjo causality scale suggested probable or possible causation for all donepezil cases. All patients had at least two other risk factors for TdP, including modifiable risk factors such as electrolyte disturbances, bradycardia, co-administration of QT prolonging drugs. A number of recent cases involved recent changes in medication.

Conclusion

Our evaluation of the case report literature suggests that there is evidence for a causal association between donepezil and QT_c/TdP risk. Attention to risk factors for QT_c prolongation/TdP should be exercised when prescribing donepezil and modifiable risk factors corrected. Owing to the low number of cases with galantamine and rivastigmine, further work is needed to establish whether these drugs may be more suitable than donepezil for patients with other risk factors for TdP.

Long term use of donepezil and QTc prolongation

BACKGROUND

The neurocognitive benefits of donepezil are well recognised, but the potential side effects on cardiac conduction remain unclear.

OBJECTIVE

To investigate whether long-term donepezil therapy is associated with electrocardiographic (ECG) changes and in particular to assess its effects on the QT interval.

METHODS

We conducted a single centre retrospective analysis of patients admitted to our trust on donepezil therapy over a 12-month period. An admission resting 12-lead ECG was obtained and compared to their ECG prior to commencement of donepezil therapy to assess for any significant difference in ECG parameters.

RESULTS

We identified 59 patients suitable for analysis. PR (177.0 ± 29.0 ms vs. 186.1 ± 34.2 ms, p = 0.04), QRS (101.7 ± 20.3 ms vs. 104.7 ± 22.3 ms, p = 0.04) and QT (393.3 ± 35.6 ms vs. 411.9 ± 44.6 ms, p = 0.002) interval prolongation were all associated with donepezil use. The increase in QT intervals remained significant on correction for heart rate; resulting in 8 (13.6%) patients developing high arrhythmogenic risk based on assessment using QT nomogram plots. Concomitant use of tricyclic antidepressants was associated with significant QT prolongation (QTcB: r _pb = 0.344, p = 0.008, QTcFred: r _pb = 0.382, p = 0.003, QTcFram: r _pb = 0.379, p = 0.003, QTcH: r _pb = 0.352, p = 0.006), while the use of rate-limiting calcium channel blockers was associated with significant PR prolongation (r _pb = 0.314, p = 0.030), and beta-blockers with a reduction in heart rate (r _pb = 0.256, p = 0.050).

CONCLUSION

Our results clearly demonstrate that long-term use of donepezil is associated with prolongation of the QT interval. We suggest ECG evaluation should take place before and after donepezil initiation, and clinicians should be even more vigilant in those prescribed tricyclic antidepressants.

The Assessment of Cerebrovascular Response to a Language Task from the Addenbrooke's Cognitive Examination in Cognitive Impairment: A Feasibility Functional Transcranial Doppler Ultrasonography Study

Background:

The incidence of dementia is predicted to rise rapidly, but sensitive diagnostic tests remain elusive. Changes in cerebral blood flow velocity (CBFv) can occur at an early stage of cognitive decline, and can be measured by transcranial Doppler ultrasonography (TCD).

Objective:

The aim of this study was to characterize the CBFv changes that occur in healthy older adults (HC), mild cognitive impairment (MCI), and Alzheimer’s disease (AD), in response to a language task from the Addenbrooke’s cognitive examination (ACE-III).

Methods:

Participants underwent bilateral TCD, continuous heart rate (ECG), end-tidal CO₂ (capnography, ETCO₂), and beat-to-beat blood pressure (Finometer, MAP), monitoring, during a 5-minute baseline, followed by cognitive tasks from the ACE-III. Data are presented for a language task (repeating words and phrases aloud), as peak percentage change in CBFv, HR, MAP, and ETCO₂ from a normalized baseline.

Results:

30 participants (mean age 73.2 years, 20% female) were recruited; HC (n = 10), MCI (n = 10), AD (n = 10). Language scores did not differ between groups (p = 0.16). Peak percentage change in CBFv differed between groups with the language task (HC: 15.9 (7.5)%, MCI: 6.7 (4.5)%, AD: 0.1 (7.1)%; p < 0.005). However, changes in MAP (HC: 7.9 (4.6)%, MCI: –0.1 (0.9)%, AD: 0.9 (4.4)%; p < 0.005), HR (HC: 8.8 (8.2)%, MCI: 0.7 (4.3)%, AD: –0.5 (5.6)%; p = 0.005), and ETCO₂ (HC: –0.9 (3.2)%, MCI: 0.9 (3.2)%, AD: –5.2 (5.7)%; p = 0.006), also occurred.

Conclusions:

TCD measured CBFv changes to a language task from the ACE-III was feasible in a cognitively impaired population, further work is required in a larger population.

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.

Het effect van galantamine op de ecg- geleidingstijden

THE EFFECT OF GALANTAMINE ON CARDIAC CONDUCTION TIME BACKGROUND

Galantamine, one of the acethylcholinesterase inhibitors (AChEI), is used in the treatment of Alzheimer's disease. However AChEI have been associated with adverse events, including cardiac events. The objective of this prospective, observational study is to evaluate the association between galantamine and incident cardiac conduction abnormalities.

METHODS

A total of 64 patients, who visited an out - patient clinic of a geriatric department were enrolled in the study. All patients were diagnosed with Alzheimer's disease and started with a capsule containing 8 mg of galantamine. Subsequently, if galantamine was well tolerated, the dosage was raised every 4 weeks, to an eventual dosage of 24 mg/ day. The mean follow - up period was 4 months. ECG parameters were evaluated at baseline and after start of galantamine at each galantamine dose level (8, 16, 24 mg / day).

RESULTS

No significant differences in electrocardiographic measurements before and during treatment with galantamine were found.

CONCLUSION

No significant changes in ECG parameters relative to baseline were found with galantamine treatment. Also after adjustment for concomitant cardioactive medications and cardiovascular comorbidity, no significant changes were found.

Cardiovascular pharmacodynamics of donepezil hydrochloride on the PR and QT intervals in patients with dementia

OBJECTIVE

Although several case reports suggested that donepezil hydrochloride can induce bradycardia or atrioventricular block, the details remain unclear. We implemented a study of the impact of donepezil hydrochloride administration on PR, RR, and QT intervals.

METHODS

The subjects were 18 patients who were diagnosed with either dementia or cognitive disorder (DSM-IV-TR) and were hospitalized between January 2011 and December 2012. After hospitalization, they were treated with donepezil hydrochloride. Clinical parameters and electrocardiograms before and after the administration of donepezil hydrochloride were retrieved from the patients' medical records.

RESULTS

After the administration of donepezil hydrochloride, the mean PR interval significantly increased from 177.3 ± 30.9 to 186.8 ± 38.4 ms (p<0.001). And the mean RR interval also significantly increased from 850.3 ± 112.5 to 886.7 ± 136.4 ms (p=0.014). The mean difference in the PR interval before and after the administration of donepezil hydrochloride was 9.5 ± 17.1 (range=-21.0-44.0) ms. The QT intervals were unaffected by the administration of donepezil hydrochloride.

CONCLUSIONS

Care should be taken when administering donepezil to patients with atrioventricular block, or patients taking other drugs that can prolong the PR interval. Copyright © 2014 John Wiley & Sons, Ltd.

Cardiac safety of donepezil in elderly patients with Alzheimer disease

OBJECTIVE

Donepezil is a widely used cholinesterase inhibitor for the treatment of Alzheimer's disease (AD), however its cholinergic adverse side effects on the cardiovascular system are still unclear. In this study, we aimed to examine the adverse side effects caused by donepezil on cardiac rhythm and postural blood pressure changes in elderly patients with Alzheimer Disease.

METHODS

The ECG parameters including heart rate, PR, QT, QTc interval and QRS duration and postural blood pressure changes were recorded at the baseline and at each donepezil dose level (5 and 10 mg/d). Patients Seventy-one consecutive patients who were referred by primary care centers to a Geriatric Clinic were enrolled and underwent comprehensive geriatric assessment.

RESULTS

Fifty-two subjects completed the study. There were no significant changes relative to the baseline in any of the ECG parameters or arterial blood pressure at any of the investigated dosages of donepezil.

CONCLUSION

It was demonstrated that donepezil was not associated with increased negative chronotropic, arrhythmogenic or hypotensive effects for elderly patients with Alzheimer's disease.

Alzheimer's disease and co-morbidity: increased prevalence and possible risk factors of excess mortality in a naturalistic 7-year follow-up

BACKGROUND

Subjects with late-onset Alzheimer's disease (AD) have to be sufficiently healthy to live long enough to experience and to be diagnosed with dementia in later life. In contrast, neurodegeneration and cognitive deficits in AD may increase the frequency of co-morbid disorders and their possible influence on mortality. Consequently, we investigated whether the pattern of co-morbidity and its relevance for later death differed between hospitalized AD and age-matched controls subjects.

METHODS

Co-morbid diseases with a prevalence of more than 1% at hospital admission were compared between 634 hospitalized AD and 72,244 control subjects aged above 70 years admitted to the University of Birmingham NHS Trust between 1 January 2000 to 31 December 2007. Risk factors, i.e. co-morbid diseases that were predictors of mortality within the 7-year follow-up, were identified and compared.

RESULTS

Subjects with AD suffer more eating disorders, infections, brain diseases and neck of femur fractures than other hospitalized elderly patients. In contrast, some cardiovascular diseases and diabetes mellitus were less prevalent in AD subjects in comparison with hospitalized controls. Diseases that might have contributed to later mortality in AD were pneumonia, ischemic heart disease and gastroenteritis, but there were no significant differences in their impact on mortality compared to other hospitalized elderly subjects with the same co-morbidities in multivariate logistic regression analyses.

CONCLUSION

Patients with AD have a different pattern of co-morbidity, but die from the same diseases as other hospitalized patients. Infections including pneumonia and diseases that may occur secondary to neurodegeneration and cognitive decline may need special attention in patients with AD who may not be able to identify or report the early symptoms. Preventive measures may be helpful to reduce the high risk and fatal consequences of undetected disease in AD.

Clinical efficacy of aniracetam, either as monotherapy or combined with cholinesterase inhibitors, in patients with cognitive impairment: a comparative open study

INTRODUCTION

Dementia constitutes an increasingly prevalent cognitive disorder with serious socioeconomic implications.

AIMS

In the present study, we aimed to evaluate the efficacy of aniracetam, either as monotherapy or combined with cholinesterase inhibitors (ChEIs), in terms of several neuropsychological parameters, in a considerable number of patients with dementia.

RESULTS

In our prospective, open-label study, we enrolled a total of 276 patients (mean age 71 ± 8 years, 95 males) with cognitive disorders. Our study population comprised four groups: no treatment group (n = 75), aniracetam monotherapy group (n = 58), ChEIs monotherapy group (n = 68), and group of combined treatment (n = 68). Patients were examined with validated neuropsychological tests at baseline, 3, 6, and 12 months of treatment. In patients treated with aniracetam, all studied parameters were adequately maintained at 6 and 12 months, while emotional state was significantly improved at 3 months. In patients treated with ChEIs, we observed a significant cognitive deterioration at 12 months. The comparison between aniracetam and ChEIs in patients with relatively mild dementia (15 ≤ MMSE ≤ 25) revealed a significantly better cognitive performance with aniracetam at 6 months and improved functionality at 3 months. Comparing aniracetam monotherapy with combined treatment in the same population, aniracetam performed better in the cognitive scale at 6 months, and displayed a notable tendency for enhanced mood at 12 months and improved functionality at 6 months.

CONCLUSIONS

Our findings indicate that aniracetam (a nootropic compound with glutamatergic activity and neuroprotective potential) is a promising option for patients with cognitive deficit of mild severity. It preserved all neuropsychological parameters for at least 12 months, and seemed to exert a favorable effect on emotional stability of demented patients.

The effect of donepezil treatment on cardiovascular mortality

The acetylcholinesterase inhibitor donepezil hydrochloride improves cognitive function in patients with Alzheimer's disease and vascular dementia. Given acetylcholine's important actions on the heart, we undertook a retrospective cohort investigation to assess whether donepezil usage affects cardiovascular mortality. In patients treated with donepezil, hazard ratios for total and cardiovascular mortality were 0.68 (P = 0.045, 95% confidence interval 0.46-0.99) and 0.54 (P = 0.042, 95% confidence interval 0.30-0.98), respectively. The apparent survival benefit in donepezil-treated patients should not be overinterpreted. Prospective clinical trials are warranted.

Cholinesterase inhibitors and hospitalization for bradycardia: a population-based study

BACKGROUND

Cholinesterase inhibitors are commonly used to treat dementia. These drugs enhance the effects of acetylcholine, and reports suggest they may precipitate bradycardia in some patients. We aimed to examine the association between use of cholinesterase inhibitors and hospitalization for bradycardia.

METHODS AND FINDINGS

We examined the health care records of more than 1.4 million older adults using a case-time-control design, allowing each individual to serve as his or her own control. Case patients were residents of Ontario, Canada, aged 67 y or older hospitalized for bradycardia between January 1, 2003 and March 31, 2008. Control patients (3:1) were not hospitalized for bradycardia, and were matched to the corresponding case on age, sex, and a disease risk index. All patients had received cholinesterase inhibitor therapy in the 9 mo preceding the index hospitalization. We identified 1,009 community-dwelling older persons hospitalized for bradycardia within 9 mo of using a cholinesterase inhibitor. Of these, 161 cases informed the matched analysis of discordant pairs. Of these, 17 (11%) required a pacemaker during hospitalization, and six (4%) died prior to discharge. After adjusting for temporal changes in drug utilization, hospitalization for bradycardia was associated with recent initiation of a cholinesterase inhibitor (adjusted odds ratio [OR] 2.13, 95% confidence interval [CI] 1.29-3.51). The risk was similar among individuals with pre-existing cardiac disease (adjusted OR 2.25, 95% CI 1.18-4.28) and those receiving negative chronotropic drugs (adjusted OR 2.34, 95% CI 1.16-4.71). We found no such association when we replicated the analysis using proton pump inhibitors as a neutral exposure. Despite hospitalization for bradycardia, more than half of the patients (78 of 138 cases [57%]) who survived to discharge subsequently resumed cholinesterase inhibitor therapy.

CONCLUSIONS

Among older patients, initiation of cholinesterase inhibitor therapy was associated with a more than doubling of the risk of hospitalization for bradycardia. Resumption of therapy following discharge was common, suggesting that the cardiovascular toxicity of cholinesterase inhibitors is underappreciated by clinicians.

Torsades de Pointes with QT prolongation related to donepezil use

An 83-year-old female, who had a history of anterior myocardial infarction, was treated for Alzheimer's disease with donepezil. She suffered from repeated diarrhea and vomiting, and experienced syncope. She was admitted to our hospital and was diagnosed with acute colitis and syncope. On admission, her heart rate was 54 beats/min with regular rhythm. Laboratory data showed a low plasma potassium level. Electrocardiogram (ECG) showed poor R progression, ST elevation, negative T in precordial leads, and marked QT prolongation. Transthoracic echocardiogram showed the enlargement of the left atrium and aneurysmal area at the apex. Torsades de Pointes (TdP) with syncope and convulsion were confirmed on ECG monitoring twice after admission. We treated her with potassium chloride and started magnesium sulfate and lidocaine, and then added isoprenaline injection. After these treatments, her heart rate increased and we did not detect TdP again. With the aging population in Japan, prescriptions for donepezil are increasing. We have to be vigilant for syncope in patients taking donepezil, which is possibly related to QT prolongation and TdP.