Efficacy of citicoline as an acute stroke treatment

Pharmacological Strategies for Stroke Intervention: Assessment of Pathophysiological Relevance and Clinical Trials

OBJECTIVES

The present review describes stroke pathophysiology in brief and discusses the spectrum of available treatments with different promising interventions that are in clinical settings or are in clinical trials.

METHODS

Relevant articles were searched using Google Scholar, Cochrane Library, and PubMed. Keywords for the search included ischemic stroke, mechanisms, stroke interventions, clinical trials, and stem cell therapy.

RESULTS AND CONCLUSION

Stroke accounts to a high burden of mortality and morbidity around the globe. Time is an important factor in treating stroke. Treatment options are limited; however, agents with considerable efficacy and tolerability are being continuously explored. With the advances in stroke interventions, new therapies are being formulated with a hope that these may aid the ongoing protective and reparative processes. Such therapies may have an extended therapeutic time window in hours, days, weeks, or longer and may have the advantage to be accessible by a majority of the patients.

Citicoline for treating people with acute ischemic stroke

BACKGROUND

Stroke is one of the leading causes of long-lasting disability and mortality and its global burden has increased in the past two decades. Several therapies have been proposed for the recovery from, and treatment of, ischemic stroke. One of them is citicoline. This review assessed the benefits and harms of citicoline for treating patients with acute ischemic stroke.

OBJECTIVES

To assess the clinical benefits and harms of citicoline compared with placebo or any other control for treating people with acute ischemic stroke.

SEARCH METHODS

We searched in the Cochrane Stroke Group Trials Register, CENTRAL, MEDLINE Ovid, Embase Ovid, LILACS until 29 January 2020. We searched the World Health Organization Clinical Trials Search Portal and ClinicalTrials.gov. Additionally, we also reviewed reference lists of the retrieved publications and review articles, and searched the websites of the US Food and Drug Administration (FDA) and European Medicines Agency (EMA).

SELECTION CRITERIA

We included randomized controlled trials (RCTs) in any setting including participants with acute ischemic stroke. Trials were eligible for inclusion if they compared citicoline versus placebo or no intervention.

DATA COLLECTION AND ANALYSIS

We selected RCTs, assessed the risk of bias in seven domains, and extracted data by duplicate. Our primary outcomes of interest were all-cause mortality and the degree of disability or dependence in daily activities at 90 days. We estimated risk ratios (RRs) for dichotomous outcomes. We measured statistical heterogeneity using the I² statistic. We conducted our analyses using the fixed-effect and random-effects model meta-analyses. We assessed the overall quality of evidence for six pre-specified outcomes using the GRADE approach.

MAIN RESULTS

We identified 10 RCTs including 4281 participants. In all these trials, citicoline was given either orally, intravenously, or a combination of both compared with placebo or standard care therapy. Citicoline doses ranged between 500 mg and 2000 mg per day. We assessed all the included trials as having high risk of bias. Drug companies sponsored six trials. A pooled analysis of eight trials indicates there may be little or no difference in all-cause mortality comparing citicoline with placebo (17.3% versus 18.5%; RR 0.94, 95% CI 0.83 to 1.07; I² = 0%; low-quality evidence due to risk of bias). Four trials found no difference in the proportion of patients with disability or dependence in daily activities according to the Rankin scale comparing citicoline with placebo (21.72% versus 19.23%; RR 1.11, 95% CI 0.97 to 1.26; I² = 1%; low-quality evidence due to risk of bias). Meta-analysis of three trials indicates there may be little or no difference in serious cardiovascular adverse events comparing citicoline with placebo (8.83% versus 7.77%; RR 1.04, 95% CI 0.84 to 1.29; I² = 0%; low-quality evidence due to risk of bias). Overall, either serious or non-serious adverse events - central nervous system, gastrointestinal, musculoskeletal, etc. - were poorly reported and harms may have been underestimated. Four trials assessing functional recovery with the Barthel Index at a cut-off point of 95 points or more did not find differences comparing citicoline with placebo (32.78% versus 30.70%; RR 1.03, 95% CI 0.94 to 1.13; I² = 24%; low-quality evidence due to risk of bias). There were no differences in neurological function (National Institutes of Health Stroke Scale at a cut-off point of ≤ 1 points) comparing citicoline with placebo according to five trials (24.31% versus 22.44%; RR 1.08, 95% CI 0.96 to 1.21; I² = 27%, low-quality evidence due to risk of bias). A pre-planned Trial Sequential Analysis suggested that no more trials may be needed for the primary outcomes but no trial provided information on quality of life.

AUTHORS' CONCLUSIONS

This review assessed the clinical benefits and harms of citicoline compared with placebo or any other standard treatment for people with acute ischemic stroke. The findings of the review suggest there may be little to no difference between citicoline and its controls regarding all-cause mortality, disability or dependence in daily activities, severe adverse events, functional recovery and the assessment of the neurological function, based on low-certainty evidence. None of the included trials assessed quality of life and the safety profile of citicoline remains unknown. The available evidence is of low quality due to either limitations in the design or execution of the trials.

Neurotechnology-aided interventions for upper limb motor rehabilitation in severe chronic stroke

Upper limb motor deficits in severe stroke survivors often remain unresolved over extended time periods. Novel neurotechnologies have the potential to significantly support upper limb motor restoration in severely impaired stroke individuals. Here, we review recent controlled clinical studies and reviews focusing on the mechanisms of action and effectiveness of single and combined technology-aided interventions for upper limb motor rehabilitation after stroke, including robotics, muscular electrical stimulation, brain stimulation and brain computer/machine interfaces. We aim at identifying possible guidance for the optimal use of these new technologies to enhance upper limb motor recovery especially in severe chronic stroke patients. We found that the current literature does not provide enough evidence to support strict guidelines, because of the variability of the procedures for each intervention and of the heterogeneity of the stroke population. The present results confirm that neurotechnology-aided upper limb rehabilitation is promising for severe chronic stroke patients, but the combination of interventions often lacks understanding of single intervention mechanisms of action, which may not reflect the summation of single intervention’s effectiveness. Stroke rehabilitation is a long and complex process, and one single intervention administrated in a short time interval cannot have a large impact for motor recovery, especially in severely impaired patients. To design personalized interventions combining or proposing different interventions in sequence, it is necessary to have an excellent understanding of the mechanisms determining the effectiveness of a single treatment in this heterogeneous population of stroke patients. We encourage the identification of objective biomarkers for stroke recovery for patients’ stratification and to tailor treatments. Furthermore, the advantage of longitudinal personalized trial designs compared to classical double-blind placebo-controlled clinical trials as the basis for precise personalized stroke rehabilitation medicine is discussed. Finally, we also promote the necessary conceptual change from ‘one-suits-all’ treatments within in-patient clinical rehabilitation set-ups towards personalized home-based treatment strategies, by adopting novel technologies merging rehabilitation and motor assistance, including implantable ones.

Neuroinflammation: friend and foe for ischemic stroke

Stroke, the third leading cause of death and disability worldwide, is undergoing a change in perspective with the emergence of new ideas on neurodegeneration. The concept that stroke is a disorder solely of blood vessels has been expanded to include the effects of a detrimental interaction between glia, neurons, vascular cells, and matrix components, which is collectively referred to as the neurovascular unit. Following the acute stroke, the majority of which are ischemic, there is secondary neuroinflammation that both promotes further injury, resulting in cell death, but conversely plays a beneficial role, by promoting recovery. The proinflammatory signals from immune mediators rapidly activate resident cells and influence infiltration of a wide range of inflammatory cells (neutrophils, monocytes/macrophages, different subtypes of T cells, and other inflammatory cells) into the ischemic region exacerbating brain damage. In this review, we discuss how neuroinflammation has both beneficial as well as detrimental roles and recent therapeutic strategies to combat pathological responses. Here, we also focus on time-dependent entry of immune cells to the ischemic area and the impact of other pathological mediators, including oxidative stress, excitotoxicity, matrix metalloproteinases (MMPs), high-mobility group box 1 (HMGB1), arachidonic acid metabolites, mitogen-activated protein kinase (MAPK), and post-translational modifications that could potentially perpetuate ischemic brain damage after the acute injury. Understanding the time-dependent role of inflammatory factors could help in developing new diagnostic, prognostic, and therapeutic neuroprotective strategies for post-stroke inflammation.

Efficacy and Safety of Vinpocetine as Part of Treatment for Acute Cerebral Infarction: A Randomized, Open-Label, Controlled, Multicenter CAVIN (Chinese Assessment for Vinpocetine in Neurology) Trial

OBJECTIVE

The objective of this study was to evaluate the efficacy and safety of intravenous vinpocetine administration as part of a comprehensive treatment for acute cerebral infarction in a Chinese population.

METHODS

610 acute cerebral infarction patients were randomized into two groups: the vinpocetine group (469 patients) received cytidine disphosphate choline 0.4-0.5 g in combination with aspirin 75-100 mg or clopidogrel 75 mg once daily, plus vinpocetine 30 mg intravenously once daily for 7 days, while the control group (141 patients) received cytidine disphosphate choline 0.4-0.5 g in combination with aspirin 75-100 mg or clopidogrel 75 mg once daily for 7 days. Additionally, patients received medications for symptoms such as hypertension, hyperglycemia, hyperlipidemia, and intracranial hypertension when necessary. Mini-Mental State Examination (MMSE), National Institutes of Health Stroke Scale (NIHSS), modified Rankin Scale, and Barthel Index (BI) scores and transcranial doppler (TCD) were assessed at baseline, 7, 14, and 90 days after treatment. Adverse events (AEs) and abnormalities in blood, urine, liver, and kidney function were monitored.

RESULTS

MMSE, NIHSS, and BI scores were significantly higher in the vinpocetine group than in the control group 90 days after treatment, indicating significantly improved cognitive skill, neurological function, and quality of life (QOL) in the vinpocetine group versus the control group. Importantly, such effects of vinpocetine were maintained over time. In addition, TCD monitoring showed significantly increased cerebral blood flow associated with vinpocetine versus control. No significant difference in safety was noted between the two groups.

CONCLUSIONS

When used as part of treatment for acute cerebral infarction, vinpocetine improves patients' cerebral blood flow, cognitive quality, neurological functions, and QOL. Vinpocetine could be an effective and safe component of treatment regimen for acute cerebral infarction.

Molecular structure and differential function of choline kinases CHKα and CHKβ in musculoskeletal system and cancer

Choline, a hydrophilic cation, has versatile physiological roles throughout the body, including cholinergic neurotransmission, memory consolidation and membrane biosynthesis and metabolism. Choline kinases possess enzyme activity that catalyses the conversion of choline to phosphocholine, which is further converted to cytidine diphosphate-coline (CDP-choline) in the biosynthesis of phosphatidylcholine (PC). PC is a major constituent of the phospholipid bilayer which constitutes the eukaryotic cell membrane, and regulates cell signal transduction. Choline Kinase consists of three isoforms, CHKα1, CHKα2 and CHKβ, encoded by two separate genes (CHKA(Human)/Chka(Mouse) and CHKB(Human)/Chkb(Mouse)). Both isoforms have similar structures and enzyme activity, but display some distinct molecular structural domains and differential tissue expression patterns. Whilst Choline Kinase was discovered in early 1950, its pivotal role in the development of muscular dystrophy, bone deformities, and cancer has only recently been identified. CHKα has been proposed as a cancer biomarker and its inhibition as an anti-cancer therapy. In contrast, restoration of CHKβ deficiency through CDP-choline supplements like citicoline may be beneficial for the treatment of muscular dystrophy, bone metabolic diseases, and cognitive conditions. The molecular structure and expression pattern of Choline Kinase, the differential roles of Choline Kinase isoforms and their potential as novel therapeutic targets for muscular dystrophy, bone deformities, cognitive conditions and cancer are discussed.

Cytidine-5-diphosphocholine reduces microvascular permeability during experimental endotoxemia

Background

Microvascular permeability and leukocyte adhesion are pivotal mechanisms in sepsis pathophysiology contributing to the development of shock and mortality. No effective pharmacological therapy is currently available to restore microvascular barrier function in sepsis. Cholinergic mediators have been demonstrated to exert anti-inflammatory effects during inflammation. Cytidine-5-diphosphocholine (CDP-choline) is an extensively studied cholinergic drug due to its brain protective characteristics in cerebrovascular diseases. This study evaluated the effect of CDP-choline on microvascular permeability and leukocyte adhesion during endotoxemia.

Methods

Macromolecular leakage, leukocyte adhesion, and venular wall shear rate were examined in mesenteric postcapillary venules of rats by using intravital microscopy (IVM). Lipopolysaccharide (LPS) (4 mg/kg/h) or equivalent volumes of saline were continuously infused following baseline IVM at 0 min. IVM was repeated after 60 and 120 min in endotoxemic and nonendotoxemic animals. CDP-choline (100 mg/kg) was applied as an i.v. bolus. Animals received either saline alone, CDP-choline alone, CDP-choline 10 min before or 30 min after LPS administration, or LPS alone. Due to nonparametric data distribution, Wilcoxon test and Dunn's multiple comparisons test were used for data analysis. Data were considered statistically significant at p < 0.05.

Results

Treatment with LPS alone significantly increased microvascular permeability and leukocyte adhesion and decreased venular wall shear rate. CDP-choline significantly reduced microvascular permeability in animals treated with LPS. Leukocyte adhesion and venular wall shear rate were not affected by CDP-choline during endotoxemia.

Conclusion

CDP-choline has a protective effect on microvascular barrier function during endotoxemia. Considering the excellent pharmacologic safety profile of CDP-choline, its use could be an approach for the treatment of capillary leakage in sepsis.

[Prescription appropriateness: Indication of citicoline in Primary Care]

INTRODUCTION

The economic situation has made it necessary to optimize resources by adjusting the pharmaceutical expenditure. Citicoline was (2011) the 10th drug by rank of billed amount. Its approved indications are stroke (acute and sub-acute) and head injury, but not cognitive decline associated with age, the presumed indication for most of its use.

OBJECTIVES

To assess the conditions of use of citicoline in the Health Area of Tenerife, in order to detect deviations from the indications of use as stipulated in the prescribing information sheet and the pattern of prescription, with emphasis on the analysis of its use in dementia where currently it has no indication or evidence to support it.

METHOD

Cross-sectional study of prescription-indication. A 680 patient sample, segmented by reference hospital (error±5%; CI: 0.95%; P=0.5) was taken from the 4036 patients with a prescription of citicoline billed during august-october 2011 (obtained from the prescription database program, Farmacanarias).

RESULTS

We found that 123 patients (18.1%) had an appropriate indication. By including the prescription regimen, 28 patients (4.1%) had adequate indication and dose levels, and in only 2 patients (0.2%) an appropriate indication, dosage and duration were found.

CONCLUSIONS

"The correct prescription-indication" of citicoline is inappropiate in almost all patients studied. Impact actions are needed in order to optimize prescription, improve patient safety by reducing potential interactions, and the occurrence of adverse effects, and improve efficiency by promoting savings.

Optimization of cytarabine (ARA-C) therapy for acute myeloid leukemia

Cytarabine (cytosine arabinoside) is one of the most effective drugs for the treatment of acute myeloid leukemia. The standard dose of cytarabine used to treat this leukemia is 100 mg per square meter. In an attempt to improve the effectiveness of cytarabine against acute myeloid leukemia, a high-dose treatment (3,000 mg per square meter) was introduced into therapy. The side effects of high-dose cytarabine was a major concern, especially its neurological toxicity. A review of recent clinical trials indicates that this high-dose cytarabine can be replaced by the intermediate-dose of 1,000 mg per square meter without loss of efficacy and with less toxicity. This is an important step to improve the efficacy of cytarabine for the treatment of acute myeloid leukemia. Despite the improvements in the therapy for this leukemia, the current overall survival rate for adult patients is less than 30%. To optimize the cytarabine therapy, it is important to determine how some leukemic stem cells survive treatment. Preclinical data suggest that survival of the leukemic stem cells could be due to the long 12 hour interval between infusions of cytarabine, which permits some leukemic cells to escape its S phase specific action. Among the other factors that can lead to leukemic cell survival are the high levels in the liver and spleen of cytidine deaminase, the enzyme that inactivates cytarabine and drug resistance due to deficiency in deoxycytidine kinase, the enzyme that activates the prodrug, cytarabine. Several approaches are proposed in this commentary to overcome these impediments with the goal of increasing the effectiveness of cytarabine for the treatment of acute myeloid leukemia.

A rapid LC-ESI-MS/MS method for the quantitation of choline, an active metabolite of citicoline: Application to in vivo pharmacokinetic and bioequivalence study in Indian healthy male volunteers

A rapid, simple, and sensitive high performance liquid chromatography-tandem mass spectrometry method (LC-ESI-MS/MS) was developed and validated for the determination and pharmacokinetic investigation of choline (CL), active metabolite of citicoline in human plasma using metformin (MF) as IS. The chromatographic separation was performed on a reversed-phase Phenomenx Gemini C18 column with a mobile phase of methanol:water (containing 10mM ammonium formate) (9:1, v/v). The calibration curves were linear over the range of 0.05-5μg/ml. The validated LC-ESI-MS/MS method was successfully applied for the evaluation of pharmacokinetic parameters and bioequivalence study of test and reference control release (CR) tablet preparation of citicoline 1000mg after a single oral administration to all 12 healthy male volunteers.

CDP-choline at high doses is as effective as i.v. thrombolysis in experimental animal stroke

Use of thrombolysis in acute ischaemic stroke may be limited by a narrow benefit/risk ratio. Pharmacological inhibition of the ischaemic cascade may constitute an effective and safer approach to stroke treatment. This study compared the effects of high doses of cytidine diphosphate-choline (CDP-choline; 1000 mg/kg) with recombinant tissue plasminogen activator (rt-PA; 5 mg/kg) in an experimental animal model of embolic stroke. Fifteen rats were embolized in the right internal carotid artery with an autologous clot and were divided into three groups: (1) infarct; (2) intravenous rt-PA 5 mg/kg 30 minutes post-embolization; and (3) CDP-choline 1000 mg/kg, intraperitoneal, three doses, 30 minutes, 24 hours, and 48 hours post-embolization. Functional evaluation scores were evaluated using Rogers test, lesion volume by haematoxylin and eosin staining, cell death with transferase-mediated dUTP nick-end labelling, and plasma levels of interleukin-6 (IL-6) and tumor necrosis factor-alpha with enzyme-linked immunosorbent assay. In this study, CDP-choline and rt-PA produced a significant reduction in brain damage considering infarct volume, cell death, and inflammatory cytokines (tumour necrosis factor-alpha and IL-6) compared with the infarct group. Additionally, CDP-choline significantly decreased infarct volume, cell death, and IL-6 levels with respect to the rt-PA group. From these results, we conclude that high-dose CDP-choline may be an effective treatment for acute ischaemic stroke even in absence of thrombolysis.

Current acute stroke trials and their potential impact on the therapeutic time window

Several trials in acute stroke are underway or have been completed recently. Among the latter, ECASS 3 was a milestone regarding the extension of the rigid 3-h time window out to 4.5 h for intravenous thrombolysis with recombinant tissue plasminogen activator. Several other approaches are being tested for thrombolytic therapy, among them modern imaging-based patient selection of patients and interventional approaches. Other pharmaceutical strategies include neuroprotection, and restoration, biophysical approaches, such as near infrared laser therapy, hemodynamic augmentation, and sphenopalatine ganglion stimulation. This perspective will cover the recently completed and currently recruiting acute stroke trials with respect to their potential role in expanding the therapeutic time window for acute ischemic stroke.

It's a lipid's world: bioactive lipid metabolism and signaling in neural stem cell differentiation

Lipids are often considered membrane components whose function is to embed proteins into cell membranes. In the last two decades, studies on brain lipids have unequivocally demonstrated that many lipids have critical cell signaling functions; they are called "bioactive lipids". Pioneering work in Dr. Robert Ledeen's laboratory has shown that two bioactive brain sphingolipids, sphingomyelin and the ganglioside GM1 are major signaling lipids in the nuclear envelope. In addition to derivatives of the sphingolipid ceramide, the bioactive lipids discussed here belong to the classes of terpenoids and steroids, eicosanoids, and lysophospholipids. These lipids act mainly through two mechanisms: (1) direct interaction between the bioactive lipid and a specific protein binding partner such as a lipid receptor, protein kinase or phosphatase, ion exchanger, or other cell signaling protein; and (2) formation of lipid microdomains or rafts that regulate the activity of a group of raft-associated cell signaling proteins. In recent years, a third mechanism has emerged, which invokes lipid second messengers as a regulator for the energy and redox balance of differentiating neural stem cells (NSCs). Interestingly, developmental niches such as the stem cell niche for adult NSC differentiation may also be metabolic compartments that respond to a distinct combination of bioactive lipids. The biological function of these lipids as regulators of NSC differentiation will be reviewed and their application in stem cell therapy discussed.

CDP-choline as a biological supplement during neurorecovery: a focused review

Cytidine 5'-diphosphocholine (CDP-choline or citicoline) is a highly bioavailable compound with potential benefits for aiding neural repair and increasing acetylcholine levels in the central and peripheral nervous system. As a result, many researchers have investigated the use of CDP-choline for various types of neurological insult or conditions, including stroke, traumatic brain injury, and Alzheimer disease. Despite the fact that the safety of the compound has been verified across multiple international studies, evidence for efficacy remains less clear. This may be attributable, at least in part, to several issues, including a lack of randomized clinical trials, a lack of availability of the compound in the United States, and statistical power issues in reported trials. In addition, the fact that CDP-choline has multiple potential points of therapeutic impact makes it an exciting treatment option in theory but also complicates the analysis of efficacy in the sense that multiple mechanisms and time points must be evaluated. Although some clinical conditions do not appear to benefit from CDP-choline treatment, the majority of findings to date have suggested at least minor benefits of treatment. In this review we will examine the evidence in the published literature pertaining to use of CDP-choline in rehabilitation populations and briefly consider the work yet to be done.

Simple diffusion delivery via brain interstitial route for the treatment of cerebral ischemia

Delivering pharmacologic agents directly into the brain has been proposed as a means of bypassing the blood brain barrier. However, despite 16 years of research on a number of central nervous system disorders, an effective treatment using this strategy has only been observed in the brain tumor glioblastoma multiforme. Within this study we propose a novel system for delivering drugs into the brain named the simple diffusion (SDD) system. To validate this technique, rats were subjected to a single intracranial (at the caudate nucleus), or intraperitoneal injection, of the compound citicoline, followed two hours later by a permanent middle cerebral artery occlusion (pMCAO). Results showed that 12 h after pMCAO, with 0.0025 g kg(-1) citicoline, an infarct volume 1/6 the size of the intraperitoneal group was achieved with a dose 1/800 of that required for the intraperitoneal group. These results suggest that given the appropriate injection point, through SDD a pharmacologically effective concentration of citicoline can be administered.

New approaches to neuroprotective drug development

All prior drug development programs of neuroprotective agents were unsuccessful for a variety of reasons related to both preclinical assessment and the design/implementation of clinical trials. The neuroprotection hypothesis of improving functional outcome related to salvaging ischemic brain tissue is strongly supported by robust preclinical data for many agents. In the future, monotherapy neuroprotection trials will be difficult but could be performed in underused centers with drugs that have very promising and complete preclinical results. Additional approaches for the testing and use of neuroprotective agents should be considered. Novel approaches would include extending penumbral survival for the later use of reperfusion therapy, reducing reperfusion injury after successful reperfusion, and using drugs with both neuroprotective and recovery enhancing effects, as exemplified by granulocyte colony-stimulating factor and citicoline. To maximize outcome after stroke, the combined use or reperfusion and neuroprotection is likely to be needed, so we must begin to perform carefully designed trials with this combination.

Making a Case for Acute Ischemic Stroke

Stroke is the third leading cause of death in the United States and the number one cause of adult long-term disability. Disability in stroke survivors includes hemiparesis, aphasia, inability to walk without assistance, dependence on others for activities of daily living, depression, and institutionalization. Immediate recognition of acute ischemic stroke (AIS) signs and symptoms is required because many treatment options are time sensitive. Hospital transport via activation of 911 and emergency medical services (EMSs) removes delays to urgent diagnosis and intervention. Intravenous (IV) recombinant tissue plasminogen (rt-PA) is a time-sensitive reperfusion strategy. The American Heart Association (AHA) and American Stroke Association (ASA) recently revised recommendations that the time window for IV rt-PA be expanded from 3 hours to 4.5 hours after symptom onset in patients with mild to moderate stroke. Supportive therapies include crystalloid IV solutions, adequate oxygenation, and normothermia. Best rest is desired along with oxygen supplementation. Avoidance of fever is paramount since fever can contribute to negative outcomes. It is the purpose of this article to review risk factors, stroke symptoms, epidemiology, and current drug therapy of AIS. Standards of care will be reviewed.