Deciphering Alzheimer's disease: predicting new therapeutic strategies via improved understanding of biology and pathogenesis

INTRODUCTION

There is no cure for Alzheimer's disease (AD). One explanation may pertain to the need to intervene as early as possible upstream from the accumulation of β-amyloid plaques and tau tangles.

AREAS COVERED

A PUBMED literature search was completed to review the biological or pathological changes at the basis of disease initiation; this includes neuroinflammation, oxidative stress, microbiome changes and glymphatic system dysfunction. Innovative therapeutic strategies based on these mechanisms are also discussed.

EXPERT OPINION

Improved understanding of the pathophysiological mechanisms that underly AD would assist in the identification of drug targets for clinical trials. Furthermore, pharmacokinetic and pharmacodynamic studies are key for the characterization of the properties of disease-modifying drugs and the improvement of their penetration of the blood-brain barrier. Drug targets can be examined at different stages of the disease, hence the importance of selecting and recruiting the appropriate participants, preferably at the earliest stage of AD. New trial designs should be established which primarily involve combination therapies that can work synergistically on common pathways. Going forward, innovative treatment strategies involving nanotechnology, young blood products transfusion and photobiomodulation also offer promise for the future.

Present Algorithms and Future Treatments for Alzheimer's Disease

An estimated 47 million people live with Alzheimer’s disease (AD) and other forms of dementia worldwide. Although no disease-modifying treatments are currently available for AD, earlier diagnosis and proper management of the disease could have considerable impact on patient and caregiver quality of life and functioning. Drugs currently approved for AD treat the cognitive, behavioral, and functional symptoms of the disease and consist of three cholinesterase inhibitors (ChEIs) and the N-methyl-D-aspartate receptor antagonist memantine. Treatment of patients with mild to moderate AD is generally initiated with a ChEI. Patients who show progression of symptoms while on ChEI monotherapy may be switched to another ChEI and/or memantine can be added to the treatment regimen. In recent years, putative disease-modifying therapies have emerged that aim to slow the progression of AD instead of only addressing its symptoms. However, many therapies have failed in clinical trials in patients with established AD, suggesting that, once developed, disease-modifying agents may need to be deployed earlier in the course of illness. The goal of this narrative literature review is to discuss present treatment algorithms and potential future therapies in AD.

Diagnostic Accuracy of the SLU AMSAD Scale for Depression in Older Adults Without Dementia

OBJECTIVES

To evaluate the diagnostic accuracy of a short depression screening tool, the Saint Louis University (SLU) AMSAD depression scale, relative to the Geriatric Depression Scale-15 (GDS-15) and Montgomery-Asberg Depression Rating Scale (MADRS), and in relation to the Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition (DSM-5) criteria for major depressive disorder, in cognitively intact older adults.

DESIGN

Cross-sectional.

SETTING

Outpatient geriatric psychiatry clinic.

PARTICIPANTS

Fifty older adults (aged ≥65 years) without dementia.

MEASUREMENTS

GDS-15, MADRS, SLU AMSAD, and DSM-5 criteria for major depressive disorder were administered.

RESULTS

Total scores (continuous variables) for the GDS-15, MADRS, and SLU AMSAD correlated significantly with the DMS-5 criteria for major depressive disorder (MDD) [area under the curve (AUC) ≥ 0.93, sensitivity = 0.93, and specificity ≥ 0.80]. Optimal cutoffs were 9+ for GDS-15, 18+ for MADRS, and 7+ for SLU AMSAD. When score results were categorized according to their known cutoffs for mild, moderate, and severe depression, AUC values were again high (range = 0.82-0.89), with adequate levels of sensitivity (0.87-0.93) and specificity (0.71-0.86), distinguishing no or mild depression from moderate or severe depression in relation to the DSM-5 diagnostic criteria for MDD.

CONCLUSIONS AND IMPLICATIONS

Strong diagnostic accuracy was shown for the 3 scales. The SLU AMSAD performed as well as the GDS-15 and slightly better than the MADRS. The superiority of the SLU AMSAD is supported by the fact that it encompasses only 5 simply worded, simply scaled items to be used in busy clinical settings.

An evaluation of hydromethylthionine as a treatment option for Alzheimer's disease

INTRODUCTION

Alzheimer's disease (AD) is a major cause of morbidity worldwide and its prevalence is expected to rise. Previous studies involving compounds that target the accumulation of amyloid β protein have been unsuccessful, renewing interest in therapies directed against intracellular deposits of tau proteins. Derived from methylene blue, hydromethylthionine is a tau aggregation inhibitor that recently emerged as a promising disease-modifying treatment for AD.

AREAS COVERED

Herein, the authors cover the chemistry, pharmacodynamics and pharmacokinetics of hydromethylthionine and its oxidized form methylthionine chloride (MTC) that was first studied, as well as clinical efficacy and safety of hydromethylthionine in the treatment of mild to moderate AD.

EXPERT OPINION

Randomized clinical trials with hydromethylthionine failed to show any impact of the doses used on the disease course. Data analysis from a non-randomized cohort showed that a smaller dose of the drug previously thought to be ineffective and used as placebo, prescribed as monotherapy rather than as add-on to AD approved symptomatic therapies may slow cognitive decline. This finding was further confirmed by a pharmacokinetic analysis study showing a dose/response relationship with doses around 16 mg daily. Future trials need to study the pharmacological properties of hydromethylthionine and ascertain the optimal safe and effective dose to be used.

Use of Cholinesterase Inhibitors in Non-Alzheimer's Dementias

Non-Alzheimer's dementias constitute 30% of all dementias and present with major cognitive and behavioral disturbances. Cholinesterase inhibitors improve memory by increasing brain acetylcholine levels and are approved symptomatic therapies for Alzheimer's disease (AD). They have also been investigated in other types of dementias with potential cholinergic dysfunction. There is compelling evidence for a profound cholinergic deficit in Lewy Body dementia (LBD) and Parkinson's disease dementia (PDD), even to a greater extent than AD. However, this deficit is difficult to objectivize in vascular dementia (VaD) given the increased comorbidity with AD. Furthermore, there is minimal to no evidence for cholinergic loss in frontotemporal dementia (FTD). Although cholinesterase inhibitors showed significant improvement in cognitive, behavioral, and functional measures in both LBD and PDD clinical trials, only rivastigmine is approved for PDD, due to the heterogeneity of the scales used, the duration of trials, and the limited sample sizes impacting data interpretation. Similarly, the interpretation of findings in VaD trials are limited by the lack of pre-defined inclusion criteria for 'pure VaD' and the wide heterogeneity of patients enrolled with respect to location and extent of cerebrovascular disease. In FTD patients, cholinesterase inhibitors were mostly associated with worsening of cognitive and behavioral symptoms. In non-AD dementias, cholinesterase inhibitors were well tolerated, with increased reports of mild to moderate cholinergic side effects and a non-significant trend for increased cardio and cerebrovascular events with rivastigmine in VaD, justifying their cautious use on a case-by-case basis, especially when there is evidence for cholinergic deficit.

The cholinergic system in the pathophysiology and treatment of Alzheimer's disease

Cholinergic synapses are ubiquitous in the human central nervous system. Their high density in the thalamus, striatum, limbic system, and neocortex suggest that cholinergic transmission is likely to be critically important for memory, learning, attention and other higher brain functions. Several lines of research suggest additional roles for cholinergic systems in overall brain homeostasis and plasticity. As such, the brain's cholinergic system occupies a central role in ongoing research related to normal cognition and age-related cognitive decline, including dementias such as Alzheimer's disease. The cholinergic hypothesis of Alzheimer's disease centres on the progressive loss of limbic and neocortical cholinergic innervation. Neurofibrillary degeneration in the basal forebrain is believed to be the primary cause for the dysfunction and death of forebrain cholinergic neurons, giving rise to a widespread presynaptic cholinergic denervation. Cholinesterase inhibitors increase the availability of acetylcholine at synapses in the brain and are one of the few drug therapies that have been proven clinically useful in the treatment of Alzheimer's disease dementia, thus validating the cholinergic system as an important therapeutic target in the disease. This review includes an overview of the role of the cholinergic system in cognition and an updated understanding of how cholinergic deficits in Alzheimer's disease interact with other aspects of disease pathophysiology, including plaques composed of amyloid-β proteins. This review also documents the benefits of cholinergic therapies at various stages of Alzheimer's disease and during long-term follow-up as visualized in novel imaging studies. The weight of the evidence supports the continued value of cholinergic drugs as a standard, cornerstone pharmacological approach in Alzheimer's disease, particularly as we look ahead to future combination therapies that address symptoms as well as disease progression.

Rational deprescribing in the elderly

BACKGROUND

Polypharmacy, defined as being prescribed 5 or more medications, has been shown to be associated with a decline in mental and physical functioning in elderly patients. Despite this, elderly patients are currently being prescribed a median of 7 medications, which often causes more harm than benefit, and emphasizes the importance of deprescribing.

METHODS

Five classes of potentially inappropriate medications for the elderly population, especially for the aging brain, are discussed, including anticholinergics, benzodiazepines, antipsychotics, opioids, and proton pump inhibitors. Recommendations regarding these medications were collected from the 2015 Beer's Criteria, the Screening Tool of Older Person's Prescriptions (STOPP) criteria, the Screening Tool to Alert doctors to the Right Treatment (START) criteria, and the Fit fOR The Aged (FORTA) list. The PubMed database was also searched for the most recent evidence regarding prescription patterns, adverse effects, and recommendations regarding discontinuation of these medications in older adults.

RESULTS

Anticholinergics, benzodiazepines, antipsychotics, and opioids were all found to have significant adverse effects in the elderly population. All of the discussed medication classes have been shown to be successfully deprescribable.

CONCLUSIONS

Polypharmacy increases the risk of adverse drug reactions and hospitalizations in geriatric patients. Rational deprescribing of anticholinergics, benzodiazepines, antipsychotics, opioids, and proton pump inhibitors in selected patients may be a good first step to reducing this risk.

Behavioral and psychological symptoms in Alzheimer's dementia and vascular dementia

Behavioral and psychological symptoms of dementia (BPSD) are highly prevalent and represent a significant burden for patients and their caregivers. Early recognition and management of these symptoms is crucial as they are associated with increased risk of institutionalization, impairments in daily functioning, reduced quality of life, and more rapid progression to severe dementia. This chapter will discuss the pathophysiology, proposed diagnostic criteria, clinical features, and management of BPSD, including apathy, depression, agitation/aggression, psychosis, and sleep disturbances. Apathy and depression are the most common overall, and apathy is associated with high symptom severity likely because of its greater persistence. Symptoms such as agitation, aggression, hallucinations, and delusions may be especially distressing and dangerous to patients and caregivers. Nonpharmacologic management should be considered first-line therapy in most cases due to the modest and inconsistent evidence base for pharmacologic agents and greater risk of harm. However, the judicious use of pharmacologic agents may be warranted when symptoms are dangerous and/or severely distressing.

Traumatic Brain Injury, Chronic Traumatic Encephalopathy, and Alzheimer Disease

Traumatic brain injury (TBI) is a major health and economic burden. With increasing aging population, this issue is expected to continue to rise. Neurodegenerative disorders are more common with aging population in general regardless of history of TBI. Recent evidence continues to support a relation between a TBI and neurocognitive decline later in life (such as in athletes and military). This article summarizes the pathologic and clinical effects of TBI (regardless of severity) on the later development of dementia in individuals 65 years or older.

Empathy changes in neurocognitive disorders: A review

BACKGROUND

Empathy can be broadly defined as the ability to understand what others feel (cognitive empathy) and feel what others feel (affective empathy). The capacity to empathize may be impaired in certain major neurocognitive disorders (MNCDs), affecting not only the patient, but also the caregivers.

METHODS

PubMed and Google Scholar databases were searched for studies investigating empathy changes, using an objective scale, in patients with MNCDs.

RESULTS

The Interpersonal Reactivity Index was most commonly used to evaluate empathy in this population. Impairments in cognitive but not affective empathy were found in patients with Alzheimer's disease (AD), and may be attributable to overall cognitive decline. Patients with frontotemporal dementia (FTD) have demonstrated severe deficits in empathy, correlating with greater caregiver burden. Empathy changes in patients with dementia with Lewy bodies, vascular dementia, and Parkinson's disease dementia have not yet been studied. Intranasal oxytocin has emerged as a promising therapeutic approach for empathy loss, but it has not been explored yet in patients with MNCDs.

CONCLUSIONS

Caregivers need to be educated about empathy loss, which is an important part of the disease process in AD and FTD. Future research should further assess empathy changes in other MNCDs, as well as explore novel treatment options in this field.

Memantine ER Maintains Patient Response in Moderate to Severe Alzheimer's Disease: Post Hoc Analyses From a Randomized, Controlled, Clinical Trial of Patients Treated With Cholinesterase Inhibitors

Memantine extended release (ER) significantly outperformed placebo on co-primary endpoints of Clinician's Interview-based Impression of Change Plus Caregiver Input (CIBIC-Plus) and baseline to endpoint changes on the Severe Impairment Battery (SIB) in a 24-week, randomized trial (NCT00322153) in patients with moderate to severe Alzheimer's disease taking a cholinesterase inhibitor (ChEI). A post hoc analysis compared patients receiving memantine ER/ChEI to placebo/ChEI for time to onset of response and if the response was maintained (achieving improvement at weeks 8, 12, or 18 and maintaining through endpoint/week 24) on the SIB, the Neuropsychiatric Inventory (NPI), CIBIC-Plus, and Activities of Daily Living (ADL) using Fisher exact test. A second post hoc analysis compared percentages of patients for all possible combinations of 2 to 4 assessments with either no decline or clinically notable response using Wald χ. Significantly greater percentages of memantine ER/ChEI patients achieved an early response that was maintained on SIB, NPI, and CIBIC-Plus (P<0.05) versus placebo/ChEI. Significantly greater percentages of memantine ER/ChEI-treated patients achieved and maintained a clinically notable response on ADL/NPI, SIB/ADL/NPI, and SIB/ADL/CIBIC-Plus, compared with placebo/ChEI (P<0.05). Memantine ER results in early, maintained improvement in patients with moderate to severe Alzheimer's disease concurrently taking ChEIs, compared with cholinesterase treatment alone.

The role of 5 HT6-receptor antagonists in Alzheimer's disease: an update

INTRODUCTION

Despite recent advances in Alzheimer's disease (AD) research, no breakthrough treatments have been discovered. Cholinesterase inhibitors and the NMDA-receptor antagonist memantine are currently the two approved symptomatic treatments for AD. 5-HT6 receptor antagonism has recently emerged as a promising treatment strategy to improve cognition in AD, with a modest side-effect profile.

AREAS COVERED

5-HT6 receptors, exclusively found in the central nervous system, modulate primarily GABA and glutamate levels, facilitating the secondary release of other neurotransmitters including dopamine, noradrenaline, and acetylcholine, all of which are compromised in AD. This review discusses findings of preclinical and phase I-III clinical trials conducted with three major 5-HT6 receptor antagonists: idalopirdine, intepirdine, and SUVN-502, in the field of AD.

EXPERT OPINION

Despite early positive findings, larger phase-III trials have failed to demonstrate any statistically significant impact on cognition for both idalopirdine and intepirdine, as adjunct to cholinesterase inhibitors. Paradoxically, 5-HT6 receptor agonists have also been shown to have cognitive enhancing properties. Thus, a better understanding of the mechanism of action of the 5-HT6 receptor and its ligands is warranted. Investigating 5-HT6 receptor partial or inverse agonists may be promising in future AD trials.

Recent Progress in the Pharmacotherapy of Alzheimer's Disease

Alzheimer's disease is the most common major neurocognitive disorder with substantial social and economic impacts. This article is an update on current pharmacotherapy, advancements in biomarker use, and drugs in the pipeline for this disease. To date, no new drug has qualified to be added to the current therapeutic arsenal comprising cholinesterase inhibitors and the NMDA receptor antagonist memantine. Drugs in the pipeline include symptomatic therapies that are neurotransmitter-based, but mostly disease-modifying therapies. The latter have yielded disappointing results by focusing mainly on the two pathophysiological hallmarks of Alzheimer's disease: Aβ amyloid deposits and tau protein aggregates forming neurofibrillary tangles. These unsuccessful trials may have resulted from studying these drugs 'too late' relative to Alzheimer's disease onset, in addition to focusing only on the amyloid cascade. In fact, Alzheimer's disease is a complex multifactorial disease. Combining different biomarkers might enhance our ability to identify those patients most at risk of developing the disease, and better predict their conversion rates. Furthermore, adopting an integrative treatment approach by targeting additional pathophysiological pathways in Alzheimer's disease such as inflammation and oxidative stress could be the key to better outcomes in Alzheimer's disease pharmacotherapy research.

An update on the safety of current therapies for Alzheimer's disease: focus on rivastigmine

Alzheimer's disease (AD) is the most common cause of major neurocognitive disorders worldwide. Despite all research efforts, therapeutic options for AD are still limited to two drug classes: cholinesterase inhibitors (ChEIs) and the NMDA-receptor antagonist memantine. Donepezil, rivastigmine and galantamine are the three ChEIs FDA-approved as first-line treatment for AD. Although they share the same mode of action, they differ in terms of their pharmacologic characteristics and route of administration, which can impact their safety and tolerability profile. Rivastigmine, available in both oral and transdermal patch formulations, is a slowly reversible dual inhibitor of acetyl and butyryl cholinesterase, selective for the G1 isoform of acetylcholinesterase, without hepatic metabolism by the CYP-450 system. Despite its unique features, it has been associated with a higher incidence of adverse events in comparison to other ChEIs. The oral form, approved for the treatment of mild to moderate AD, is associated with a higher incidence of gastrointestinal side effects. The transdermal patch formulation approved for use across all stages of AD has been shown to have a better tolerability profile in comparison to both the oral form and even other ChEIs. One important tolerability concern is adverse dermatologic reactions, which are mostly benign, and can be either preventable or manageable. One important safety concern is the risk of treatment overdose by administering multiple patches at the same time, potentially leading to fatal outcomes. This can be prevented by educating patients and caregivers about the proper use of the patch. The goal for the future would be to optimize the patch formulation to increase both efficacy and safety.

Renal concerns relative to the use of lithium in geriatric bipolar disorder patients

BACKGROUND

Lithium is a first-line treatment for bipolar disorder in geriatric patients; however, it has long been associated with potentially significant renal consequences, including chronic kidney disease (CKD).

METHODS

We reviewed the available evidence to characterize the effects of lithium on renal function, provide a consensus on periodic monitoring, and propose criteria for transitioning an older patient with bipolar disorder and renal issues to an alternate medication.

RESULTS

Although the evidence on lithium use, duration, and dosage on progression of CKD and end-stage renal disease in geriatric patients is mixed, there is solid evidence that patients receiving lithium generally have a reduced glomerular filtration rate compared with controls. The current guidelines for monitoring lithium use in geriatric patients are nearly sufficient, but adherence in clinical practice frequently falls short. Alternative medications for bipolar disorder in geriatric patients are generally considered safe and effective, but do not have the strength of evidence that exists in the general adult population.

CONCLUSIONS

Currently, there is no compelling evidence that lithium should be avoided in geriatric patients; however, prudent monitoring strategies are recommended, with a strong consideration of transitioning geriatric patients with poor tolerance to an alternative medication.

Emerging chemical therapies targeting 5-hydroxytryptamine in the treatment of Alzheimer's disease

INTRODUCTION

Alzheimer's disease (AD) is a major neuropsychiatric disorder affecting more than 5 million Americans over age 65. By the year 2050, AD is expected to affect over 30 million. Characterized by neuronal cell death accompanied by the accumulation of neurofibrillary tangles and neuritic plaques, AD results in devastating clinical symptomatology with a lasting psychosocial and financial impact. Studies have shown that the current treatments for AD, cholinesterase inhibitors (ChEI's) and NMDA receptor antagonists, have limited efficacy. The 5-HT-6 receptor antagonists Idalopirdine and Intepirdine have shown the most progress in current clinical trials and warrant consideration as emerging treatments for AD. Areas covered: This review discusses 5-HT6 antagonists currently in clinical trials as potential treatments for AD symptomatology and how 5-HT6 physiology may play a positive role in alleviating AD symptom pathophysiology. A literature search using PubMed was conducted using the terms Idalopirdine, Intepirdine, 5-HT-6 antagonist, and AD as keywords. Clinicaltrials.gov and Alzforum were also used to obtain information on clinical trials. Expert opinion: If current Phase-3 trials are positive, 5-HT6 antagonists such as Idalopirdine and Intepirdine may be considered as supplementary treatments to ChEI's and NMDA receptor antagonists for the symptomatic treatment of AD.

Rapid Depression Assessment in Geriatric Patients

Depression is common in geriatric patients, especially in those with multiple comorbidities and polypharmacy. Depression in older adults is often underdiagnosed and undertreated. Initial screening for depression can easily be accomplished in the waiting room. Yet the clinical interview still remains the gold standard for diagnosing geriatric depression. Key components of the clinical interview are observant watching of the patient for the subtle signs of depression. Clinical interview should be done with sensitivity to the importance of privacy. Illicit substances and medical conditions may significantly contribute. Suicide assessment should be done in a step wise manner.

AVP-786 for the treatment of agitation in dementia of the Alzheimer's type

INTRODUCTION

Agitation is common and distressing in patients with Alzheimer-type dementia, but safe, effective treatments remain elusive. Psychological treatments are first-line options, but they have limited efficacy. Off-label psychotropic medications are frequently used, but they also have limited effectiveness, and their use may have harmful side effects, including death. Areas covered: This review discusses the history leading to the conception of AVP-786 (deuterated (d6)-dextromethorphan/quinidine), its pharmacokinetic and pharmacodynamic profiles and safety issues, together with an overview of recent clinical trials. Data were found in the medical literature, in US and EU clinical trial registries and in information provided by the manufacturer. Expert opinion: AVP-786 is one of six investigational compounds in recent phase III clinical development for agitation in Alzheimer disease (AD). Quinidine and deuteration appear to prolong dextromethorphan's plasma half-life and facilitate brain penetration. The FDA granted fast-track designation to AVP-786 and allowed use of data generated on dextromethorphan-quinidine (AVP-923, Nuedexta®) for regulatory filings. AVP-923 reduced agitation in AD and was well tolerated in a phase II RCT that included more than 200 patients. A phase III clinical development program of AVP-786 for AD agitation was recently initiated. This program is expected to start generating results in July 2018.

Ideomotor limb apraxia as a staging tool in individuals with Alzheimer's disease (ILIAD)

BACKGROUND

Ideomotor apraxia (IMA) is known to affect individuals with Alzheimer's disease (AD). Combined with impaired cognitive function, IMA can support evidence of probable AD. However, apraxia is a condition that is difficult to diagnose. The Postural Knowledge Test (PKT), developed by Mozaz et al, was designed to easily identify limb apraxia in multiple sclerosis yet demonstrated potential utility for AD. ILIAD is a pilot study to investigate correlation between the PKT and Mini-Mental State Examination (MMSE).

METHODS

Participants with mild, moderate, and severe AD were administered the MMSE by 1 examiner, followed by the PKT by a second blinded examiner.

RESULTS

Seventy-seven participants with mild (25), moderate (26), and severe AD (26) met study criteria. Correlation was demonstrated between the MMSE and PKT at 0.835 among all AD groups. Correlation between MMSE and PKT-1 (transitive) and PKT-2 (intransitive) separately was 0.819 and 0.793.

CONCLUSIONS

There is significant correlation between the MMSE (memory loss) and PKT (IMA). This suggests the PKT may be used in conjunction with the MMSE to aid in staging AD and to monitor disease severity. Correlation between the MMSE and separate PKT tests suggests that administration of only 1 test may be necessary clinically, saving valuable time.

A fixed-dose combination of memantine extended-release and donepezil in the treatment of moderate-to-severe Alzheimer's disease

Currently available therapies for the treatment of Alzheimer’s disease (AD) consist of cholinesterase inhibitors (ChEIs), such as donepezil, and the N-methyl-D-aspartate receptor antagonist memantine. In December 2014, the US Food and Drug Administration approved Namzaric™, a once-daily, fixed-dose combination (FDC) of memantine extended-release (ER) and donepezil for patients with moderate-to-severe AD. The FDC capsule is bioequivalent to the coadministered individual drugs, and its bioavailability is similar when taken fasting, with food, or sprinkled onto applesauce. The combination of memantine and ChEIs in moderate-to-severe AD provides additional benefits to ChEI monotherapy across multiple domains and may delay the time to nursing home admission. A dedicated study of memantine ER compared to placebo in patients on a stable dose of a ChEI found statistically significant benefits on cognition and global status but not functioning. Treatment with memantine ER and donepezil is generally well tolerated, although higher doses of ChEIs are associated with more serious adverse events such as vomiting, syncope, and weight loss. Potential advantages of the FDC include a simpler treatment regimen, reduction in pill burden, and the ability to sprinkle the capsule onto soft foods. Patients who may benefit from the FDC include those with significant dysphagia, a history of poor compliance, or limited caregiver interaction. However, available evidence that these advantages would increase treatment adherence and persistence is conflicting, meaning that the added cost of switching patients from generic options to an FDC may not always be justified.