Blood pressure targets, medication considerations and special concerns in elderly hypertension III: Focus on stroke and neurodegenerative disorders

Controlling hypertension has become an important issue in the elderly population in whom neurological comorbidities are highly prevalent. Most of the large-scale trials focusing on hypertension management in older populations have excluded patients with comorbid neurological disorders. However, this population requires special considerations, as the benefits of antihypertensive agents are mostly uncertain and there is a higher risk of adverse events. In this review article, we discuss current evidence regarding the management of elderly patients with hypertension and common neurological disorders, including stroke and neurodegenerative diseases. In elderly patient with a history of stroke, the blood pressure management strategy is generally similar to that for young patients, however the benefits of stroke prevention from blood pressure control are less significant. For patients with neurodegenerative disorders such as cognitive dysfunction and Parkinson's disease, achieving adequate blood pressure control may be beneficial in reducing cardiovascular risks, although the higher risk of adverse events from antihypertensive treatment may offset some of these benefits. Special considerations for factors such as orthostatic hypotension, risk of falls, polypharmacy, and significant drug-drug interactions are required but frequently neglected in clinical practice. More efforts are warranted to determine the optimal treatment strategy for elderly populations with neurological disorders.

Patients with dementia: prevalence and type of drug-drug interactions

Background

Patients with Alzheimer's disease (AD) and other dementias are more frequently exposed to polymedication, mainly due to the presence of comorbidities, are particularly vulnerable to drug-related problems, and present greater risk of adverse effects due to drug-drug interactions (DDIs).

Purpose

To assess the prevalence of clinically relevant interactions in dementia patients using a routine database, we describe the most frequent interactions and risk factors associated with them to facilitate specific interventions and programs to prevent and minimize them.

Methods

An observational, descriptive, and cross-sectional study that included patients with AD and other types of dementia (n = 100, 64% female) was conducted to identify potential DDI in their treatment using the Lexi-Interact/Lexicomp® database.

Results

A total of 769 drugs were prescribed, involving 190 different active ingredients; 83% of the treatments included five or more drugs. DDI occurred in 87% of the patients, of which 63.2% were female. A total of 689 DDIs were found, grouped in 448 drug pairs, with a mean of 6.9 ± 7.1 (range, 0-31) DDIs per patient, and 680 DDIs were considered clinically relevant. It was observed that 89.8% of the DDIs had a moderate level of severity, 23.5% had a good level of relevance, and pharmacodynamic-based DDIs accounted for 89.5%. The drugs most frequently involved in DDIs were quetiapine (24.5%) and acetylsalicylic acid (10%). A total of 97 DDIs were detected between the acetylcholinesterase inhibitors (AChEIs), and the remaining drugs were administered concomitantly. One of the most frequent DDIs was between AChEIs and beta-blocking agents (n = 29, 4.3%). The most important factors that showed the strongest association with the presence of drug interactions were the use of AChEIs (p = 0.01) and the total number of drugs (p = 0.014) taken by the patient.

Conclusion

Patients with dementia present increased risk of DDIs. Among the most common drugs are psychotropic drugs, which are involved in pharmacodynamic interactions caused by the concomitant use of CNS-targeted drugs. The results highlight the difficulty to evaluate DDIs in clinical practice due to polymedication and variety of comorbidities. Therefore, it is important to review their treatment and consider metabolism inhibition or induction, and potentially P450 substrate overlapping.

A geroscience motivated approach to treat Alzheimer's disease: Senolytics move to clinical trials

The pathogenic processes driving Alzheimer's disease (AD) are complex. An incomplete understanding of underlying disease mechanisms has presented insurmountable obstacles for developing effective disease-modifying therapies. Advanced chronological age is the greatest risk factor for developing AD. Intervening on biological aging may alter disease progression and represents a novel, complementary approach to current strategies. Toward this end, cellular senescence has emerged as a promising target. This complex stress response harbors damaged cells in a cell cycle arrested, apoptosis-resistant cell state. Senescent cells accumulate with age where they notoriously secrete molecules that contribute to chronic tissue dysfunction and disease. Thus, benefits of cell survival in a senescent fate are countered by their toxic secretome. The removal of senescent cells improves brain structure and function in rodent models at risk of developing AD, and in those with advanced Aβ and tau pathology. The present review describes the path to translating this promising treatment strategy to AD clinical trials. We review evidence for senescent cell accumulation in the human brain, considerations and strategies for senescence-targeting trials specific to AD, approaches to detect senescent brain cells in biofluids, and summarize the goals of the first senolytic trials for the treatment of AD (NCT04063124 and NCT04685590). This article is part of the Special Issue - Senolytics - Edited by Joao Passos and Diana Jurk.

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.

Cardiovascular Complications of Acetylcholinesterase Inhibitors in Patients with Alzheimer's Disease: A Narrative Review

While acetylcholinesterase inhibitors are used to treat a wide range of patients with Alzheimer's disease, acetylcholinesterase inhibitor use has also been associated with a variety of cardiovascular complications, including bradycardia and syncope. Herein, we review the pathophysiology and clinical evidence for cardiovascular complications caused by acetylcholinesterase inhibitors in patients being treated for dementia and discuss options for their management.

Frequency and Severity of Adverse Drug Reactions to Medications Prescribed for Alzheimer's Disease in a Brazilian City: Cross-Sectional Study

Background: There is lack of national studies that assess the risks associated with the drugs provided under the Brazilian public health system for treating Alzheimer’s disease. Then, this study determined the prevalence and severity of self-reported adverse drug reactions (ADRs) prescribed to patients with Alzheimer’s disease in the Brazilian public health system.

Methods: A cross-sectional study was carried out based on public data from the MEDEX system (information on dispensing data, known as exceptional dispensing medications) and interviews with patients and/or caregivers who get access to Alzheimer’s drugs at a public pharmacy in a large Brazilian city, between July and September 2017, inquiring about ADRs and serious adverse events (SAEs).

Results: The subjects were asked about ADRs and SAEs related to the use of donepezil, galantamine, rivastigmine and memantine. Out of 285 patients enrolled on the database, 250 participated in the study (87.7%). Among the participants, approximately 63.0% were female, 70.3% aged ≥75 years and 70.3% had comorbidities. Overall, 209 patients (83.6%) reported at least one ADR (total 1,149 ADRs) and rivastigmine was associated with the largest number of ADRs per patient (7.9 ADRs/patient). The predominant adverse effects were psychiatric disorders with common frequency (57.1%) and mild severity (89.0%). Six patients (2.4%) had SAEs that required hospitalization. The use of antipsychotics was the variable associated with ADR (OR = 4.95; 95% CI: 1.45–16.93; p = 0.011).

Conclusion: There was a large number of reported ADRs and most of them were of common frequency and mild severity, being mainly related to psychiatric disorders. Considering the fragility of these patients, it is important to improve safety-related care in the use of drugs for treating this disease.

Identifying and Characterizing Serious Adverse Drug Reactions Associated With Drug-Drug Interactions in a Spontaneous Reporting Database

Background: Drug-drug interactions (DDIs) are an important cause of adverse drug reactions (ADRs). In literature most of studies focus only on potential DDIs, while detailed data on serious ADRs associated with DDIs are limited. Our aim is to identify and characterize serious ADRs caused by DDIs using a spontaneous reporting database.

Methods: All serious ADR reports, not related to vaccines and with a “definite”, “probable” or “possible” causality assessment, inserted into the National Pharmacovigilance database from Veneto Region (January 1, 2015 to May 31, 2020) were analyzed. A list of drug pairs was created by selecting the reports containing at least two suspected or concomitant drugs. We verified which drug pairs potentially interacted according to the online version of DRUGDEX^® system. For each potential DDI we controlled whether the ADR description in the report corresponded to the interaction effect as described in Micromedex. A detailed characterization of all serious reports containing an occurring DDI was performed.

Results: In the study period a total of 31,604 reports of suspected ADRs from the Veneto Region were identified, of which 2,195 serious reports (6.9% of all ADR reports) containing at least two suspected or concomitant drugs were analyzed. We identified 1,208 ADR reports with at least one potential DDI (55.0% of 2,195) and 381 reports (17.4% of 2,195 reports) with an occurring ADR associated with a DDI. The median age of patients and the number of contraindicated or major DDIs were significantly higher in reports with an occurring DDI. Warfarin was the most frequently reported interacting drug and the most common ADRs were gastrointestinal or cerebral hemorrhagic events. The proton pump inhibitors/warfarin, followed by platelet aggregation inhibitors/warfarin were the drug-drug combinations most frequently involved in ADRs caused by DDIs. The highest proportion of fatal reports was observed with platelet aggregation inhibitors/warfarin and antidepressants/warfarin.

Conclusion: Our findings showed that about one-third of patients exposed to a potential DDI actually experienced a serious ADR. Furthermore, our study confirms that a spontaneous reporting database could be a valuable resource for identifying and characterizing ADRs caused by DDIs and the drugs leading to serious ADRs and deaths.

Influence of combinations of drugs that act on the CYP2D6 metabolic pathway in the treatment of major depressive disorder: A population-based study

Objective

To describe the frequency of drug combinations (substrate-substrate or substrate-inhibitor) with the potential to interfere with the CYP2D6 metabolic pathway in patients receiving antidepressant medication for major depressive disorder.

Methods

We carried out an observational study using outpatient medical records. We included adult subjects who initiated antidepressant medication during 2008–2010. Patients were assigned to three study groups: no combination, substrate-substrate, and substrate-inhibitor. Follow-up period was 12 months. Main measures: demographics, comorbidity and medication persistence. Statistical analysis included a logistic regression model, P < 0.05.

Results

Five thousand six hundred and thirty patients were recruited (61.9 years, 76.9% female), 24.4% (CI: 23.8 – 26.0%) received some kind of drug combination (substrate-substrate: 15.4%, substrate-inhibitor: 9.0%). Variables significantly associated with drugs combinations that may act on the CYP2D6 metabolic pathway were: dementia (OR = 4.2), neuropathy (OR = 4.2) and stroke (OR = 1.9), P < 0.001. Medication persistence at 12 months was longer in patients with no combination (55.3%) than in patients receiving substrate-substrate (50.5%) or substrate-inhibitor (45.0%) combinations, P < 0.001.

Conclusions

Twenty-five percent of major depressive disorder patients received a combination of drugs with the potential to interfere with CYP2D6 metabolic pathway. These combinations increased with comorbidity and resulted in shorter medication persistence of antidepressant treatment.

Detection of drug-drug interactions through data mining studies using clinical sources, scientific literature and social media

Drug-drug interactions (DDIs) constitute an important concern in drug development and postmarketing pharmacovigilance. They are considered the cause of many adverse drug effects exposing patients to higher risks and increasing public health system costs. Methods to follow-up and discover possible DDIs causing harm to the population are a primary aim of drug safety researchers. Here, we review different methodologies and recent advances using data mining to detect DDIs with impact on patients. We focus on data mining of different pharmacovigilance sources, such as the US Food and Drug Administration Adverse Event Reporting System and electronic health records from medical institutions, as well as on the diverse data mining studies that use narrative text available in the scientific biomedical literature and social media. We pay attention to the strengths but also further explain challenges related to these methods. Data mining has important applications in the analysis of DDIs showing the impact of the interactions as a cause of adverse effects, extracting interactions to create knowledge data sets and gold standards and in the discovery of novel and dangerous DDIs.

Predictors of Cholinesterase Discontinuation during the First Year after Nursing Home Admission

OBJECTIVES

For persons with dementia, the appropriate duration of cholinesterase inhibitor (ChEI) use remains unclear. We examined patterns of ChEI use during nursing home (NH) transition and the factors associated with discontinuation following admission.

DESIGN

Population-based retrospective cohort study using linked health administrative and Resident Assessment Instrument Minimum Dataset, version 2.0 databases.

SETTING AND PARTICIPANTS

A total of 47,851 older adults (mean age = 84.8 years, standard deviation = 6.8) with dementia newly admitted to a NH in Ontario, Canada between 2011 and 2015.

MEASUREMENTS

ChEI use at admission and during the following year was identified from prescription claims. Resident sociodemographic and health characteristics at admission, including a 72-item frailty index, were derived from the Resident Assessment Instrument Minimum Dataset 2.0. Additional resident and prescriber characteristics were derived from administrative data. Discontinuation was defined as a 30+-day gap in ChEI supply. Multivariable subdistribution hazard models were used to estimate the independent effect of resident frailty and other factors on ChEI discontinuation.

RESULTS

Approximately one-third (17,560) of residents with dementia were on a ChEI at admission. Among this group, 17.7% (3110) discontinued use over follow-up. Incidence of discontinuation was significantly higher among residents with syncope [subdistribution hazard ratio, sHR = 2.21, 95% confidence interval, CI (1.52, 3.22)], more severe behavioral symptoms [sHR = 1.79, 95% CI (1.57, 2.05)], cognitive impairment [sHR = 1.26, 95% CI (1.07, 1.48)], higher frailty, [sHR = 1.19, 95% CI (1.04, 1.36)], and a primary prescriber active in the NH [sHR = 1.28, 95% CI (1.14, 1.45)]. A significantly lower incidence was observed for older and unmarried residents and those with a longer duration of use.

CONCLUSIONS/IMPLICATIONS

Less than one-fifth of residents on a ChEI at admission discontinued use during the following year. Although some of the predictors of discontinuation align with past research and current clinical recommendations, others were unexpected and point to novel drivers of ChEI use. Future investigations should explore the varied reasons underlying these associations and resident outcomes associated with ChEI discontinuation.

A Systematic Review of Practice Guidelines and Recommendations for Discontinuation of Cholinesterase Inhibitors in Dementia

Cholinesterase inhibitors (ChEIs) are the primary pharmacological treatment for symptom management of Alzheimer disease (AD), but they carry known risks during long-term use, and do not guarantee clinical effects over time. The balance of risks and benefits may warrant discontinuation at different points during the disease course. Indeed, although there is limited scientific study of deprescribing ChEIs, clinicians routinely face practical decisions about whether to continue or stop medications. This review examined published practice recommendations for discontinuation of ChEIs in AD. To characterize the scientific basis for recommendations, we first summarized randomized controlled trials of ChEI discontinuation. We then identified practice guidelines by professional societies and in textbooks and classified them according to 1) whether they made a recommendation about discontinuation, 2) what the recommendation was, and 3) the proposed grounds for discontinuation. There was no consensus in guidelines and textbooks about discontinuation. Most recommended individualized discontinuation decisions, but there was essentially no agreement about what findings or situations would warrant discontinuation, or even about what domains to consider in this process. The only relevant domain identified by most guidelines and textbooks was a lack of response or a loss of effectiveness, both of which can be difficult to ascertain in the course of a progressive condition. Well-designed, long-term studies of discontinuation have not been conducted; such evidence is needed to provide a scientific basis for practice guidelines. It seems reasonable to apply an individualized approach to discontinuation while engaging patients and families in treatment decisions. .

Acetylcholinesterase inhibitors for treating dementia symptoms - a safety evaluation

INTRODUCTION

The prevalence of Alzheimer's disease (AD) continues to rise, while treatment options for cognitive impairment are limited. Acetylcholinesterase inhibitors (AChEIs) aim to provide symptomatic benefit for cognitive decline, however these drugs are not without adverse events (AEs). The safety profile of each drug must be taken carefully into consideration before being prescribed, as new dosages and formulations have recently been approved. Areas covered: Donepezil, galantamine and rivastigmine are the three AChEIs approved for the treatment of varying stages of AD. Numerous clinical trials and post-marketing studies have evaluated the safety of these medications. This article will review the safety, efficacy and tolerability of these drugs in treating AD. Topics including pharmacovigilance databases, concomitant drug interactions, prescribing cascades, and treatment discontinuation are also covered. Expert opinion: AChEI use in those with mild, moderate or severe AD provide modest improvements in cognition, function and behavior. The pharmacological treatment of AD using AChEIs is associated with generally mild AEs. Differences in drug formulations should be taken into account when determining the most appropriate route of administration for each individual. Furthermore, discontinuation of AChEIs must be carefully monitored as it may be associated with worsening cognitive impairment.

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.

Atropinic burden of prescriptions forms in patients with Alzheimer disease: a cross-sectional study in a French PharmacoVigilance Database

AIM

Atropinic drugs in patients with Alzheimer disease (AD) can decrease the effects of anticholinesterase drugs and/or induce adverse drug reactions (ADRs). Several atropinic risk scales defining an atropinic burden of drugs were proposed but were little used in AD patients.

METHODS

All ADRs' notifications of AD patients registered in the Midi-Pyrénées PharmacoVigilance Database between 1999 and 2013 were analyzed using Anticholinergic Drug Scale (ADS) and Anticholinergic Duran's list. The primary objective was to quantify atropinic burden in AD patients and the secondary one to investigate associated factors.

RESULTS

Among the 475 notifications, at least one atropinic drug was found in 282 notifications (59.4%) according to ADS and 214 (45.1%) according to Duran. Mean number of atropinics per notifications was 0.9 ± 0.9 (ADS) and 0.7 ± 0.9 (Duran). Mean atropinic burden per notifications was 1.2 ± 1.5 (ADS) and 0.9 ± 1.3 (Duran). Atropinic burden ≥ 3 was found in 87 notifications (18.2%) according to ADS and 50 (10.5%) according to Duran. There was no association between atropinic burden and age of patients. The number of drugs is associated to a high atropinic burden.

CONCLUSION

The present work found an association between an atropinic drug and an anticholinesterase agent in around 1 out of 2 AD patients and a clinically significant atropinic burden (≥ 3) in around 1 to 2 AD patients out of 10. The benefit harm balance of atropinic drugs must be discussed before each prescription in AD patients.

Long-term efficacy and toxicity of cholinesterase inhibitors in the treatment of Alzheimer disease

Though the symptoms of Alzheimer disease go on for years, the phase 3 trials of the cholinesterase inhibitors (ChEIs), the current mainstay of symptomatic pharmacotherapy for this condition, were typically of only 3- to 6-months' duration. We have limited data on long-term (that is, a year or more) therapy with these agents. In this review, we explore the available information on the biological and clinical effects of long-term ChEI therapy, what happens when these agents are discontinued, and examine what others have recommended An individualized approach to deciding on whether to carry on with a ChEI should be taken. If continued, treatment goals should be clarified and patients monitored over time, for both drug-related benefits and adverse effects.

Drug interactions between antihypertensive drugs and non-steroidal anti-inflammatory agents: a descriptive study using the French Pharmacovigilance database

Drug-drug interactions (DDIs) between antihypertensive drugs and non-steroidal anti-inflammatory drugs (NSAIDs) can lead to adverse drug reactions (ADRs). Guidelines are available to help prescribers deal with these drug associations, but their implementation is not well evaluated. The aims of this study were to assess the prevalence of NSAIDs exposure in patients treated with antihypertensive drugs, using the French Pharmacovigilance database, and explore the ADRs related to DDIs between antihypertensive drugs and NSAIDs. Over the 11, 442 notifications of ADRs recorded in this database in patients treated with oral antihypertensive drugs between 2008 and 2010, 517 (4.5 and 95% CI: 4.1-4.9) also included exposure to NSAIDs. These subjects were more frequently women, took more drugs in general, and were younger and less frequently treated with antiplatelet drugs. In 24.2% of them (125 patients), a DDI between NSAIDs and antihypertensive drugs was potentially the cause of the reported ADR. Acute renal failure caused by DDIs between NSAIDs and angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), or diuretics was the most frequently reported ADR (20.7%). Finally, in the French Pharmacovigilance database, around one-fourth of associations NSAIDs  +  antihypertensive drugs are associated with a 'serious' ADR (mainly acute renal failure), suggesting that this well-known DDI is not enough taken into account by prescribers.

Adverse drug reactions caused by drug-drug interactions reported to Croatian Agency for Medicinal Products and Medical Devices: a retrospective observational study

Aim

To analyze potential and actual drug-drug interactions reported to the Spontaneous Reporting Database of the Croatian Agency for Medicinal Products and Medical Devices (HALMED) and determine their incidence.

Methods

In this retrospective observational study performed from March 2005 to December 2008, we detected potential and actual drug-drug interactions using interaction programs and analyzed them.

Results

HALMED received 1209 reports involving at least two drugs. There were 468 (38.7%) reports on potential drug-drug interactions, 94 of which (7.8% of total reports) were actual drug-drug interactions. Among actual drug-drug interaction reports, the proportion of serious adverse drug reactions (53 out of 94) and the number of drugs (n = 4) was significantly higher (P < 0.001) than among the remaining reports (580 out of 1982; n = 2, respectively). Actual drug-drug interactions most frequently involved nervous system agents (34.0%), and interactions caused by antiplatelet, anticoagulant, and non-steroidal anti-inflammatory drugs were in most cases serious. In only 12 out of 94 reports, actual drug-drug interactions were recognized by the reporter.

Conclusion

The study confirmed that the Spontaneous Reporting Database was a valuable resource for detecting actual drug-drug interactions. Also, it identified drugs leading to serious adverse drug reactions and deaths, thus indicating the areas which should be in the focus of health care education.

The importance of drug-drug interactions as a cause of adverse drug reactions: a pharmacovigilance study of serotoninergic reuptake inhibitors in France

PURPOSE

To quantify the importance of drug-drug interactions (DDIs) in the occurrence of adverse drug reactions (ADRs) reported with serotoninergic reuptake inhibitors in a pharmacovigilance database.

METHODS

All spontaneous reports of ADRs registered in 2008 by the Midi-Pyrénées PharmacoVigilance Centre that contained mention of one of the serotoninergic reuptake inhibitor (SRI) antidepressants marketed in France were reviewed. DDIs were identified according to the French National Drug Formulary (Vidal) and the interaction supplement of the French independent drug bulletin La Revue Prescrire. ADRs explained by DDIs were characterised.

RESULTS

Among the 2,101 spontaneous reports recorded, 177 involved at least one SRI antidepressant. Among the 156 ADRs with at least one theoretical DDI, 41% (95% confidence interval 34-49%) could be explained by a DDI. The most frequent antidepressant involved in DDIs was escitalopram, followed by fluoxetine and citalopram. Among the 65 ADRs related to DDIs, 37 (52.9%) were "serious", mainly bleedings, confusion and falls, hyponatremia and serotoninergic syndromes. The most frequent drug interactions occurred with psychotropics (antipsychotics, benzodiazepines, among others), followed by antithrombotic agents (antagonists of vitamin K, antiplatelets), diuretics and angiotensin II antagonists. The group with ADRs related to DDIs was older than the group with ADRs not related to DDIs. ADRs were threefold more "serious" in the case of DDIs.

CONCLUSION

Around 40% of ADRs reported with SRIs were related to DDIs. Most of these occurred after association with psychotropics, antithrombotics, or diuretics, especially in the elderly.

Epidemiology and characteristics of adverse drug reactions caused by drug-drug interactions

INTRODUCTION

Drug-drug interactions (DDIs) arise in numerous different ways, involving pharmacokinetic or pharmacodynamic mechanisms. Adverse drug reactions are a possible consequence of DDIs and health operators are often unaware of the clinical risks of certain drug combinations. Many papers on drug interactions have been published in recent years, but most of them focused on potential DDIs while few studies have been conducted on actual interactions.

AREAS COVERED

This paper reviews the epidemiology of actual DDIs in outpatients as well as in hospital settings and in spontaneous reporting databases. The incidence of actual DDIs is consistently lower than that of potential DDIs. However, the absolute number of patients involved is high, representing a significant proportion of adverse drug reactions. The importance of risk factors such as age, polypharmacy and genetic polymorphisms is also evaluated. The relevance and efficacy of tools for recognizing and preventing DDIs are discussed.

EXPERT OPINION

Potential DDIs far outnumber actual drug interactions. The potential for an adverse interaction to occur is often theoretical, and clinically important adverse effects occur only in the presence of specific risk factors. Several studies have shown the efficacy of computers in early detection of DDIs. However, a correct risk-benefit evaluation by the prescribing physician, together with a careful clinical, physiological and biochemical monitoring of patients, is essential. Future directions of drug interaction research include the increasing importance of pharmacogenetics in preventing DDIs and the evaluation of interactions with biological drugs.

Effects of cholinesterase inhibitors on postoperative outcomes of older adults with dementia undergoing hip fracture surgery

OBJECTIVES

Cholinesterase inhibitors (ChEIs) may interact with muscle relaxants given during general anesthesia (GA), increasing the risk of postoperative complications. We evaluated the effects of ChEIs on the postoperative outcomes of older adults who underwent hip fracture surgery.

DESIGN

Population-based cohort study using linked administrative databases.

PARTICIPANTS

All individuals with dementia age 66 years or older, who underwent hip fracture surgery between April 1, 2003, and December 31, 2007, in Ontario, Canada.

EXPOSURES

Use of any ChEI (donepezil, rivastigmine, or galantamine) before surgery.

OUTCOMES

The primary composite outcome included any of the following: 30-day postoperative mortality; intensive care unit admissions; or in-hospital resuscitation. Secondary outcomes included postoperative respiratory failure and pneumonia.

ANALYSIS

We stratified the study sample on the basis of residence (community or long-term care [LTC]) and type of anesthetic (general or regional) to create four residence/anesthesia groups. We used propensity scores to match users and nonusers of ChEIs within the residence/anesthesia strata. We then calculated the relative risks (RR) and 95% confidence intervals (CI) for outcomes associated with ChEIs in the matched groups.

RESULTS

A total of 624 pairs of individuals from the community and 725 pairs from LTC were created among individuals who received GA. High rates of postoperative mortality and complications were observed in both ChEI users and nonusers. The RR of the primary outcome associated with ChEI use for individuals receiving GA was 0.88 (95% CI: 0.68-1.16; χ2 = 0.93; df = 1; p = 0.34) and 0.82 (95% CI: 0.63-1.04; χ2 = 2.59; df = 1; p = 0.11) in the community and LTC groups, respectively. In addition, ChEIs were not associated with any significant increased risk of postoperative respiratory complications.

CONCLUSIONS

ChEI use was not associated with an increased risk of postoperative complications among older adults with dementia who underwent hip fracture surgery. However, the poor postoperative outcomes overall reinforced the need to prevent fractures and improve outcomes in this population.

Identifying adverse drug reactions associated with drug-drug interactions: data mining of a spontaneous reporting database in Italy

BACKGROUND

Drug-drug interactions (DDIs) are an important cause of adverse drug reactions (ADRs). Many studies have recently considered this issue, but most of them focus only on potential interactions and are often related to the hospital setting. A spontaneous reporting database could be a valuable resource for detection of ADRs associated with DDIs; however, data in the literature are limited.

OBJECTIVE

To detect those patients treated with potentially interacting drugs and the cases where reported adverse reactions are a possible consequence of DDIs, using an Italian spontaneous reporting database.

METHODS

The data were obtained from a database containing all reports of suspected ADRs from five Italian regions (January 1990 to December 2007) that are the main contributors to the Italian spontaneous reporting system. All reports containing at least two drugs, reported as being suspected of causing the ADR or as concomitant medication, were selected and a list of drug pairs was drawn up. We performed a search to verify which drug pairs are considered a potential DDI, using the Internet version of the DRUGDEX(R) system. For each report containing a potential DDI, we verified whether the description of the adverse reaction corresponded to the interaction effect.

RESULTS

The database contained 45 315 reports, of which 17 700 (39.1%) had at least two reported drugs. We identified 5345 (30.2%) reports with potential DDIs, and in 1159 (21.7%) of these reports a related ADR was reported. The percentage of reports with potential DDIs increased in relation to the number of concomitantly administered drugs, ranging from 9.8% for two drugs to 88.3% for eight or more drugs. The percentages of serious or fatal reports of ADRs associated with a DDI were significantly higher than other reports analysed. The mean age, percentage of male patients and the mean number of drugs were also significantly higher in reports with DDIs than in other reports. In 235 of 1159 reports (20.3%), both interacting drugs were recognized as suspect by the reporter. This percentage varies in relation to the drugs involved, ranging from 2% to about 65%. The most frequently reported interaction was digoxin and diuretics, but no fatal ADRs were reported with this combination. The combination of anticoagulant and antiplatelet agents was responsible for the greatest number of serious reactions and deaths.

CONCLUSIONS

This study validates that spontaneous reporting, despite its limitations, can be an important resource for detecting ADRs associated with the concomitant use of interacting drugs. Moreover, our data confirm that DDIs could be a real problem in clinical practice, showing that more than one in five patients exposed to a potential DDI experienced a related ADR.

Anticoagulation and psychotropic medications

Anticoagulants and psychotropic medications are commonly prescribed together. Thus, the potential for interaction exists. Whereas thrombolytics and heparins are implicated in few pharmacokinetic interactions, warfarin and platelet inhibitors have been implicated in various interactions with psychotropic medications. In this article, I review the various psychotropic drug classes' relationships to anticoagulants. In a field devoid of randomized, placebo-controlled trials, clinical vigilance is advised when managing patients on concomitant therapy.

Predictive factors of discontinuation and switch of cholinesterase inhibitors in community-dwelling patients with Alzheimer's disease: a 2-year prospective, multicentre, cohort study

BACKGROUND

The efficacy of cholinesterase inhibitors (ChEIs), especially over the long term, is still under discussion. There is a lack of data concerning the optimal drug treatment duration and the reasons for discontinuation, particularly outside the clinical trial setting.

OBJECTIVE

To identify predictive factors of discontinuation and switch of ChEIs in a real-world setting.

METHODS

A multicentre cohort study of 686 patients with mild-to-moderate ambulatory Alzheimer's disease who were diagnosed in 16 Alzheimer's disease expert centres in 2000-2 and who were assessed twice yearly for 2 years. The main outcome measure was ChEI discontinuation and switch (analysed using Cox survival analyses).

RESULTS

After 2 years, of the 611 subjects treated with a ChEI at baseline, 100 subjects had switched or discontinued ChEI therapy (incidence rate 12.7 [95% CI 10.2, 15.2] per 100 person-years). The incidences of switching and discontinuation were 9.2 (95% CI 7.0, 11.3) and 3.6 (95% CI 2.3, 4.8) per 100 person-years, respectively. In the multivariate analysis, predictive factors for switching were an ineffective ChEI dose (adjusted hazard ratio [HR(a)] = 6.91, 95% CI 3.08, 15.49), rapid cognitive decline (HR(a) = 4.10, 95% CI 1.85, 9.05), hospitalization unrelated to Alzheimer's disease (HR(a) = 2.33, 95% CI 1.07, 5.09) and anxiety (HR(a) = 2.08, 95% CI 1.16, 3.73). Predictive factors of discontinuation were: hospitalization related (HR(a) = 9.14, 95% CI 2.69, 31.07) or unrelated (HR(a) = 4.23, 95% CI 1.54, 11.59) to Alzheimer's disease, use of an anticholinergic drug (HR(a) = 4.26, 95% CI 1.46, 12.45) and weight loss (HR(a) = 3.77, 95% CI 1.15, 12.33).

CONCLUSIONS

This study highlights four types of predictors of switch or discontinuation, reflecting disease progression, reconsideration of ChEI benefits, adverse drug reactions to ChEIs and inappropriate concurrent use of anticholinergic drugs. Attention should be paid to anticholinergic agents and prescribers should be given better information about these drugs.

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

BACKGROUND

Cholinesterase inhibitors are used in Alzheimer's disease, mostly in elderly persons with co-morbidities and receiving co-medications that could increase the risk of serious adverse reactions.

OBJECTIVE

To identify factors associated with serious adverse drug reactions (ADRs) in patients treated with cholinesterase inhibitors.

METHODS

All ADRs associated with donepezil, rivastigmine or galantamine were identified in the French pharmacovigilance database, from the launching of these drugs to January 2007. Serious ADRs (SADRs) were those that led to death, hospitalization or prolongation of hospitalization, or that were life threatening. A multiple logistic regression analysis was used to identify factors associated with seriousness in the reported adverse reactions.

RESULTS

We identified 773 reports of ADRs related to cholinesterase inhibitor use, among which 438 (57%) concerned SADRs. The median age of patients was 80 years (interquartile range: 75-84 years); 65.1% were women. The most represented ADRs were those responsible for CNS disorders (17.0%), gastrointestinal disorders (16.2%) and cardiac rhythm disorders (11.2%). Factors associated with an increased risk of SADRs were: age (odds ratio [OR] 1.92; 95% CI 1.22, 3.02 for subjects aged 85 years and over), use of atypical antipsychotics (OR 2.15; 95% CI 1.04, 4.46), use of conventional antipsychotics (OR 2.06, 95% CI 1.10, 3.85), use of antihypertensive drugs (OR 2.11; 95% CI 1.47, 3.02) and use of drugs targeting the alimentary tract and metabolism (OR 1.62; 95% CI 1.06, 2.46). The use of benzodiazepines (long-acting or others), antidepressants (tricyclic or others) or antiarrhythmic drugs was not associated with the reporting of SADRs.

CONCLUSIONS

An increased risk of SADRs related to cholinesterase inhibitors was associated with the use of antipsychotics (with no difference between conventional and atypical antipsychotics), drugs targeting the alimentary tract/metabolism and antihypertensive drugs. It was not associated with the use of other psychotropic drugs, other non-psychotropic CNS drugs or with the use of antiarrhythmic agents. The association with drugs targeting the alimentary tract and metabolism could result from a protopathic bias or reflect the particular sensitivity to serious nausea and vomiting in patients already treated for gastrointestinal disorders. These results confirm that attention needs to be paid to patients receiving both cholinesterase inhibitors and antipsychotics.

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.

Quality of interaction database management systems

Objective

To identify drug interaction databases (DID) and assess the quality of their structures.

Method

A search was made of the literature for DID and a series of exclusion and structural quality criteria were defined (at least 4 quality criteria: classification according to severity, classification according to level of evidence, bibliographical reference data, description of clinical management, and 11 criteria used for weighting). The level of compliance of every DID with the criteria defined was analysed, together with the level of compliance of each criteria in each DID.

Results

A total of 54 DID were identified, 30 of which complied with exclusion criteria and 15 of which did not meet the minimum criteria. The rest of the criteria were evaluated in 9 DID: Botplus and Medinteract (100%), SEFH Guide, Lexi-interact and Medscape (89%), Hansten (83%), Micromedex and Stockley (78%), Drug Interactions Facts (68%). Ninety-two percent of the DID describe the mechanism of action, 87% classify the information according to the active ingredient, 75% do not state they have any conflict of interest, classify according to level of severity, have electronic format, and are easy to search. A total of 67% are specific DID, 62% are classified according to level of evidence, contain bibliographical references, and describe clinical management.

Conclusions

A third of the DID comply with the minimum criteria. Differences were observed in the level and compliance criteria among Spanish and foreign DID. Some of the main DID used as references in the bibliography have significant structural defects: no web presentation, no multi-check function and others.

Current awareness: Pharmacoepidemiology and drug safety

In order to keep subscribers up‐to‐date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of pharmacoepidemiology and drug safety. Each bibliography is divided into 20 sections: 1 Reviews; 2 General; 3 Anti‐infective Agents; 4 Cardiovascular System Agents; 5 CNS Depressive Agents; 6 Non‐steroidal Anti‐inflammatory Agents; 7 CNS Agents; 8 Anti‐neoplastic Agents; 9 Haematological Agents; 10 Neuroregulator‐Blocking Agents; 11 Dermatological Agents; 12 Immunosuppressive Agents; 13 Autonomic Agents; 14 Respiratory System Agents; 15 Neuromuscular Agents; 16 Reproductive System Agents; 17 Gastrointestinal System Agents; 18 Anti‐inflammatory Agents ‐ Steroidal; 19 Teratogens/fetal exposure; 20 Others. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted.