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CNS Drugs Nov 2022For decades, treatment of mood disorders, psychoses, anxiety and dementia have been confounded by limited efficacy and high rates of treatment resistance. Preclinical... (Meta-Analysis)
Meta-Analysis
BACKGROUND
For decades, treatment of mood disorders, psychoses, anxiety and dementia have been confounded by limited efficacy and high rates of treatment resistance. Preclinical and clinical evidence have highlighted disruption of cholinergic signalling in several neuropsychiatric conditions and examined intervention strategies including acetylcholinesterase inhibitors and nicotinic receptor-targeted intervention. However, the effectiveness of these approaches is often curtailed by on-target side effects. Post mortem studies implicate muscarinic receptor dysregulation in neuropsychiatric pathophysiology; therefore, we conducted a systematic review and meta-analysis to investigate the therapeutic efficacy and safety of muscarinic receptor-targeted interventions in adults with neuropsychiatric disorders.
METHODS
PubMed, EMBASE, PsycINFO, EBSCO and Web of Science were searched using relevant keywords from database inception to 7 August 2022. Randomised, double-blind, placebo-controlled studies were included if they investigated the effect of muscarinic receptor-targeted intervention in adults with a diagnosis of a neuropsychiatric disorder and were published in English. A narrative synthesis approach was adopted to describe the findings. Wherever three or more studies with a similar intervention were available, effect sizes were calculated, and a meta-analysis was performed. Cochrane risk-of-bias-2 tool was utilised to assess the risk of bias, and sensitivity analyses were performed to identify publication bias. Certainty analysis (high, moderate, low and/or very low) was conducted using GRADE criteria.
RESULTS
Overall, 33 studies met the inclusion criteria and 5 were included in the meta-analysis. Despite a limited pool with several different interventions, we found therapeutic efficacy of xanomeline (M/M agonist) in primary psychotic disorders plus behavioural and psychological symptoms of dementia. Scopolamine showed a significant antidepressant effect in a combined cohort of major depressive and bipolar disorders in the short-term outcome measure, but no effect following cessation of treatment. Results from bias assessments suggest "very low" certainty in the antidepressant effect of scopolamine. Critical limitations of the current literature included low power, high heterogeneity in the patient population and a lack of active comparators.
CONCLUSION
While the results are not definitive, findings on muscarinic receptor-targeted interventions in several mental disorders are promising in terms of efficacy and safety, specifically in treating schizophrenia, mood disorders, and behavioural and psychiatric symptoms of Alzheimer's disease. However, orthosteric muscarinic receptor-targeted interventions are associated with a range of peripheral adverse effects that are thought to be mediated via M/M receptors. The orthosteric binding site of muscarinic acetylcholine receptors is remarkably conserved, posing a challenge for subtype-selective interventions; nonetheless allosteric ligands with biased signalling pathways are now in development. We conclude that adequately powered prospective studies with subtype-selective interventions are required to determine the clinical effectiveness of muscarinic-receptor targeted interventions for the treatment of neuropsychiatric disorders.
Topics: Adult; Humans; Depressive Disorder, Major; Prospective Studies; Acetylcholinesterase; Treatment Outcome; Antidepressive Agents; Receptors, Muscarinic; Scopolamine Derivatives; Dementia; Randomized Controlled Trials as Topic
PubMed: 36269510
DOI: 10.1007/s40263-022-00964-8 -
Age and Ageing Sep 2023Anticholinergic medications block the neurotransmitter acetylcholine in the brain and peripheral nervous system. Many medications have anticholinergic properties, and... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
Anticholinergic medications block the neurotransmitter acetylcholine in the brain and peripheral nervous system. Many medications have anticholinergic properties, and the cumulative effect of these medications is termed anticholinergic burden. Increased anticholinergic burden can have short-term side effects such as dry mouth, blurred vision and urinary retention as well as long-term effects including dementia, worsening physical function and falls.
METHODS
We carried out a systematic review (SR) with meta-analysis (MA) looking at randomised controlled trials addressing interventions to reduce anticholinergic burden in older adults.
RESULTS
We identified seven papers suitable for inclusion in our SR and MA. Interventions included multi-disciplinary involvement in medication reviews and deprescribing of AC medications. Pooled data revealed no significant difference in outcomes between control and intervention group for falls (OR = 0.76, 95% CI: 0.52-1.11, n = 647), cognition (mean difference = 1.54, 95% CI: -0.04 to 3.13, n = 405), anticholinergic burden (mean difference = 0.04, 95% CI: -0.11 to 0.18, n = 710) or quality of life (mean difference = 0.04, 95% CI: -0.04 to 0.12, n = 461).
DISCUSSION
Overall, there was no significant difference with interventions to reduce anticholinergic burden. As we did not see a significant change in anticholinergic burden scores following interventions, it is likely other outcomes would not change. Short follow-up time and lack of training and support surrounding successful deprescribing may have contributed.
Topics: Humans; Aged; Quality of Life; Cholinergic Antagonists; Acetylcholine; Brain; Cognition
PubMed: 37740900
DOI: 10.1093/ageing/afad176 -
Schizophrenia Bulletin Jul 2017Kynurenic acid (KYNA) is an endogenous antagonist of N-methyl-D-aspartate and α7 nicotinic acetylcholine receptors that is derived from astrocytes as part of the... (Meta-Analysis)
Meta-Analysis Review
Kynurenic acid (KYNA) is an endogenous antagonist of N-methyl-D-aspartate and α7 nicotinic acetylcholine receptors that is derived from astrocytes as part of the kynurenine pathway of tryptophan degradation. Evidence suggests that abnormal KYNA levels are involved in the pathophysiology of schizophrenia. However, this has never been assessed through a meta-analysis. A literature search was conducted through Ovid using Embase, Medline, and PsycINFO databases (last search: December 2016) with the search terms: (kynuren* or KYNA) and (schizophreni* or psychosis). English language studies measuring KYNA levels using any method in patients with schizophrenia and healthy controls (HCs) were identified. Standardized mean differences (SMDs) were calculated to determine differences in KYNA levels between groups. Subgroup analyses were separately performed for nonoverlapping participant samples, KYNA measurement techniques, and KYNA sample source. The influences of patients' age, antipsychotic status (%medicated), and sex (%male) on study SMDs were assessed through a meta-regression. Thirteen studies were deemed eligible for inclusion in the meta-analysis. In the main analysis, KYNA levels were elevated in the patient group. Subgroup analyses demonstrated that KYNA levels were increased in nonoverlapping participant samples, and centrally (cerebrospinal fluid and brain tissue) but not peripherally. Patients' age, %medicated, and %male were each positively associated with study SMDs. Overall, KYNA levels are increased in patients with schizophrenia, specifically within the central nervous system. An improved understanding of KYNA in patients with schizophrenia may contribute to the development of novel diagnostic approaches and therapeutic strategies.
Topics: Adult; Female; Humans; Kynurenic Acid; Male; Schizophrenia
PubMed: 28187219
DOI: 10.1093/schbul/sbw221 -
Frontiers in Immunology 2021Myasthenia gravis (MG) is an autoimmune disease primarily mediated by acetylcholine receptor antibodies (AChR-Ab), cellular immune dependence, and complement system... (Review)
Review
Myasthenia gravis (MG) is an autoimmune disease primarily mediated by acetylcholine receptor antibodies (AChR-Ab), cellular immune dependence, and complement system involvement. Since the AChR on the postsynaptic membrane is destroyed by an immune attack, sufficient endplate potential cannot be generated, resulting in the development of a synaptic transmission disorder at the neuromuscular junction and in muscle weakness. The role of the complement system in MG has been demonstrated in animal models and clinical tests, and it has been determined that complement inhibition in patients with MG can prevent disease induction and reverse its progression. Eculizumab is a humanized monoclonal antibody that inhibits the cleavage of complement protein C5 and prevents autoimmune damage; additionally, it has received subsequent approval by the Federal Drug Administration of the United States for MG treatment. However, various concerns regarding the use of eculizumab persist. In this review, we have discussed the treatment time, cost effectiveness, long-term efficacy, and tolerability of eculizumab for MG treatment. We have also summarized historical information and have presented perspectives on this new therapeutic modality.
Topics: Animals; Antibodies, Monoclonal, Humanized; Clinical Trials as Topic; Combined Modality Therapy; Complement Inactivating Agents; Complement System Proteins; Disease Management; Disease Susceptibility; Drug Development; Humans; Myasthenia Gravis; Treatment Outcome
PubMed: 34456922
DOI: 10.3389/fimmu.2021.715036 -
BMC Ophthalmology Jul 2023Dry eye disease (DED) is caused by a persistently unstable tear film leading to ocular discomfort and is treated mainly with tear supplementation. There is emerging... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Dry eye disease (DED) is caused by a persistently unstable tear film leading to ocular discomfort and is treated mainly with tear supplementation. There is emerging evidence that nicotinic acetylcholine receptor (nAChR) agonists (e.g., varenicline and simpinicline) nasal sprays are effective for DED. Our systematic review and meta-analysis assessed the efficacy and safety of varenicline nasal spray (VNS) for DED treatment.
METHODS
The Medline, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) databases were searched. Only randomized controlled trials (RCTs) that evaluated the efficacy of VNS versus placebo were included. The efficacy endpoint was the mean change in the anesthetized Schirmer test score (STS), a measure of basal tear production, from baseline. The safety endpoints were serious adverse events (SAEs) and adverse events (AEs). The standardized mean difference (SMD) was used for continuous outcomes, while the risk ratio (RR) was used to demonstrate dichotomous variables. The certainty of the evidence was rated utilizing the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. The risk of bias assessment was conducted using the Revised Cochrane risk of bias tool for randomized trials.
RESULTS
Three RCTs (n = 1063) met the eligibility criteria. All RCTs had a low risk of bias. The meta-analysis found a statistically significant increase in the mean STS change from baseline on day 28. The pooled analysis found no significant difference between VNS and placebo in the frequency of SAEs and ocular AEs. However, VNS had a significant effect on developing nasal cavity-related AEs.
CONCLUSION
VNS caused a highly significant improvement regarding the efficacy endpoint but caused an increased frequency of some nasal cavity-related AEs (i.e., cough and throat irritation). However, it caused neither SAEs nor ocular AEs. Included studies had a low risk of bias.
Topics: Humans; Nasal Sprays; Varenicline; Dry Eye Syndromes
PubMed: 37452334
DOI: 10.1186/s12886-023-03069-y -
Frontiers in Pharmacology 2020Fatigue, as a complex, multidimensional symptom, is associated with many physical illnesses. C. A. Mey (PG) is an important herbal drug which has been used for...
BACKGROUND
Fatigue, as a complex, multidimensional symptom, is associated with many physical illnesses. C. A. Mey (PG) is an important herbal drug which has been used for benefiting Qi for thousand years. C. A. Mey and its compounds (PGC) possess various pharmacological activities, including anti-fatigue. Here, we conducted a systematic review of both randomized clinical trials (RCTs) and preclinical animal studies to investigate the efficacy and safety of PGC for fatigue.
METHODS
Electronic searches were performed in 7 databases from the time of each database's inception to August 2019. The methodological quality of RCTs was assessed using 7-item checklist recommended by Cochrane Collaboration or by the CAMARADES 10-item quality checklist. All the data were analyzed using Rev-Man 5.3 and Stata SE software.
RESULTS
Eight eligible RCTs and 30 animal studies were identified. The risk of bias scores in RCTs ranged from 4/7 to 7/7, and of animal studies varied from 4/10 to 7/10. Meta-analyses showed that PGC was superior to placebo according to their respective fatigue scales, heart rate recovery, and clinical effect (P < 0.05). There were a similar number of adverse effects between PGC and placebo group (P > 0.05). Meta-analyses showed that PGC can significantly decrease level of blood lactate, blood urea nitrogen, creatine kinase, malondialdehyde, and lactic dehydrogenase in serum, level of malondialdehyde in liver and level of gamma-aminobutyric acid, 5-hydroxytryptamine in brain tissue, and increase swimming time, level of glutathione peroxidase, glucose, superoxide dismutase in serum, level of glycogen and activity of superoxide dismutase, glutathione peroxidase, and catalase in skeletal muscle, level of hepatic glycogen in liver and level of dopamine, acetylcholine in brain tissue, compared with control (P < 0.05). Meta-analyses showed no significant difference in animal body weight between PGC and control (P > 0.05).
CONCLUSION
The present findings supported, to a certain degree, that PGC can be recommended for routine use in fatigue. The possible mechanism of PGC resists fatigue, mainly through antioxidant stress, regulating carbohydrate metabolism, delaying the accumulation of metabolites, promoting mitochondrial function, neuroprotection, antiapoptosis, and regulating neurotransmitter disorder in central nervous system.
PubMed: 32765262
DOI: 10.3389/fphar.2020.01031 -
The Cochrane Database of Systematic... Oct 2014In myasthenia gravis, antibody-mediated blockade of acetylcholine receptors at the neuromuscular junction abolishes the naturally occurring 'safety factor' of synaptic... (Review)
Review
BACKGROUND
In myasthenia gravis, antibody-mediated blockade of acetylcholine receptors at the neuromuscular junction abolishes the naturally occurring 'safety factor' of synaptic transmission. Acetylcholinesterase inhibitors provide temporary symptomatic treatment of muscle weakness but there is controversy about their long-term efficacy, dosage and side effects. This is the second update of a review published in The Cochrane Library Issue 2, 2011.
OBJECTIVES
To evaluate the efficacy of acetylcholinesterase inhibitors in all forms of myasthenia gravis.
SEARCH METHODS
On 8 July 2014 we searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL, MEDLINE and EMBASE for randomised controlled trials and quasi-randomised controlled trials regarding usage of acetylcholinesterase inhibitors in myasthenia gravis. Two authors scanned the articles for any study eligible for inclusion. We also contacted the authors and known experts in the field to identify additional published or unpublished data and searched clinical trials registries for ongoing trials.
SELECTION CRITERIA
The types of studies were randomised or quasi-randomised trials. Participants were myasthenia gravis patients diagnosed by an internationally accepted definition. The intervention was treatment with any form of acetylcholinesterase inhibitor. Types of outcome measures Primary outcome measureImprovement in the presenting symptoms within one to 14 days of the start of treatment. Secondary outcome measures(1) Improvement in the presenting symptoms more than 14 days after the start of treatment.(2) Change in impairment measured by a recognised and preferably validated scale, such as the quantitative myasthenia gravis score, within one to 14 days and more than 14 days after the start of treatment.(3) Myasthenia Gravis Association of America post-intervention status more than 14 days after start of treatment.(4) Adverse events including muscarinic side effects.
DATA COLLECTION AND ANALYSIS
One author (MMM) extracted the data, which were checked by a second author. We contacted study authors for extra information and collected data on adverse effects from the trials.
MAIN RESULTS
We did not find any large randomised or quasi-randomised trials of acetylcholinesterase inhibitors in generalised myasthenia gravis either for the first version of this review or this update. One cross-over randomised trial using intranasal neostigmine in a total of 10 participants was only available as an abstract. It included three participants with ocular myasthenia gravis and seven with generalised myasthenia gravis. Symptoms of myasthenia gravis (measured as improvement in at least one muscle function) improved in nine of the 10 participants after the two-week neostigmine treatment phase. No participant improved after the placebo phase. Lack of detail in the report meant that the risk of bias was unclear. Adverse events were minor.
AUTHORS' CONCLUSIONS
Except for one small and inconclusive trial of intranasal neostigmine, no other randomised controlled trials have been conducted on the use of acetylcholinesterase inhibitors in myasthenia gravis. The response to acetylcholinesterase inhibitors in observational studies is so clear that a randomised controlled trial depriving participants in a placebo arm of treatment would be difficult to justify.
Topics: Administration, Intranasal; Cholinesterase Inhibitors; Humans; Myasthenia Gravis; Neostigmine; Randomized Controlled Trials as Topic
PubMed: 25310725
DOI: 10.1002/14651858.CD006986.pub3 -
Drug and Alcohol Dependence Oct 2022Nicotine produces its effects by binding to nicotinic acetylcholine receptors (nAChRs). Variants of genes encoding properties of nAChRs are candidates for affecting... (Review)
Review
BACKGROUND
Nicotine produces its effects by binding to nicotinic acetylcholine receptors (nAChRs). Variants of genes encoding properties of nAChRs are candidates for affecting likelihood of smoking cessation.
METHODS
A systematic review was conducted summarizing evidence of associations between single nucleotide polymorphisms (SNPs) of nAChR genes and smoking cessation. From 24 articles meeting inclusion criteria, summary odds ratios (ORs) for associations between nine SNPs and smoking cessation were calculated from 26 studies (N = 233-29,072) stratified by gene, ancestry, study design, and pharmacotherapy; SNPs in linkage disequilibrium were pooled. Results for a tenth SNP from two GWAS were summarized.
RESULTS
People of European ancestry with minor alleles of CHRNA5 rs16969968 and CHRNA3 rs1051730 had longer time to cessation [HR = 0.90, 95 % CI 0.88 - 0.92 (n = 2 studies)] and lower odds of cessation [OR = 0.88, 95 % CI 0.80 - 0.97 (n = 5 cohort studies), OR = 0.64, 95 % CI 0.45 - 0.90 (n = 4 placebo arms)]. Risk of persistent smoking associated with these alleles was attenuated in smokers receiving nicotine replacement therapy (NRT). Recipients of bupropion alone or with NRT with these alleles had higher, though not statistically significant, odds of cessation. Results for CHRNA5 rs588765 and rs680244 were similar to rs16969968/rs1051730 findings. Evidence was limited for other SNPs.
CONCLUSION
Evidence consistently indicates the minor alleles of four SNPs within CHRNA3 or CHRNA5 are risk alleles for cessation failure. Analysis by pharmacotherapy revealed bupropion may be the most efficacious intervention for people with these alleles.
Topics: Bupropion; Genetic Variation; Humans; Nicotine; Polymorphism, Single Nucleotide; Receptors, Nicotinic; Smoking Cessation; Tobacco Products; Tobacco Use Cessation Devices
PubMed: 35981468
DOI: 10.1016/j.drugalcdep.2022.109596 -
Frontiers in Cellular Neuroscience 2016Oligodendrogenesis and oligodendrocyte precursor maturation are essential processes during the course of central nervous system development, and lead to the myelination... (Review)
Review
Oligodendrogenesis and oligodendrocyte precursor maturation are essential processes during the course of central nervous system development, and lead to the myelination of axons. Cells of the oligodendrocyte lineage are generated in the germinal zone from migratory bipolar oligodendrocyte precursor cells (OPCs), and acquire cell surface markers as they mature and respond specifically to factors which regulate proliferation, migration, differentiation, and survival. Loss of myelin underlies a wide range of neurological disorders, some of an autoimmune nature-multiple sclerosis probably being the most prominent. Current therapies are based on the use of immunomodulatory agents which are likely to promote myelin repair (remyelination) indirectly by subverting the inflammatory response, aspects of which impair the differentiation of OPCs. Cells of the oligodendrocyte lineage express and are capable of responding to a diverse array of ligand-receptor pairs, including neurotransmitters and nuclear receptors such as γ-aminobutyric acid, glutamate, adenosine triphosphate, serotonin, acetylcholine, nitric oxide, opioids, prostaglandins, prolactin, and cannabinoids. The intent of this review is to provide the reader with a synopsis of our present state of knowledge concerning the pharmacological properties of the oligodendrocyte lineage, with particular attention to these receptor-ligand (i.e., neurotransmitters and nuclear receptor) interactions that can influence oligodendrocyte migration, proliferation, differentiation, and myelination, and an appraisal of their therapeutic potential. For example, many promising mediators work through Ca(2+) signaling, and the balance between Ca(2+) influx and efflux can determine the temporal and spatial properties of oligodendrocytes (OLs). Moreover, Ca(2+) signaling in OPCs can influence not only differentiation and myelination, but also process extension and migration, as well as cell death in mature mouse OLs. There is also evidence that oligodendroglia exhibit Ca(2+) transients in response to electrical activity of axons for activity-dependent myelination. Cholinergic antagonists, as well as endocannabinoid-related lipid-signaling molecules target OLs. An understanding of such pharmacological pathways may thus lay the foundation to allow its leverage for therapeutic benefit in diseases of demyelination.
PubMed: 26903812
DOI: 10.3389/fncel.2016.00027 -
Acta Psychiatrica Scandinavica Apr 2022The authors conducted a systematic review and meta-analysis of pharmacological interventions to diminish cognitive side effects of ECT. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
The authors conducted a systematic review and meta-analysis of pharmacological interventions to diminish cognitive side effects of ECT.
METHODS
Electronic databases of Pubmed, PsycInfo, Embase and Scopus were searched from inception through 1 April, 2021, using terms for ECT (e.g. electroconvulsive therapy), cognitive outcome (e.g. cogni*) and pharmacological intervention (e.g. calcium channel blocker and general terms, like protein). Original studies with humans receiving ECT were included, which applied pharmacological interventions in comparison with placebo or no additive intervention to diminish cognitive side effects. Data quality was assessed using Risk of Bias and GRADE. Random-effects models were used. PROSPERO registration number was CRD42021212773.
RESULTS
Qualitative synthesis (systematic review) showed 52 studies reporting sixteen pharmacological intervention-types. Quantitative synthesis (meta-analysis) included 26 studies (1387 patients) describing twelve pharmacological intervention-types. Low-quality evidence of efficacy was established for memantine (large effect size) and liothyronine (medium effect size). Very low-quality evidence shows effect of acetylcholine inhibitors, piracetam and melatonin in some cognitive domains. Evidence of no efficacy was revealed for ketamine (very low-quality), herbal preparations with anti-inflammatory properties (very low to low-quality) and opioid receptor agonists (low-quality).
CONCLUSION
Memantine and liothyronine are promising for further research and future application. Quality of evidence was low because of differences in ECT techniques, study populations and cognitive measurements. These findings provide a guide for rational choices of potential pharmacological intervention research targets to decrease the burden of cognitive side effects of ECT. Future research should be more uniform in design and attempt to clarify pathophysiological mechanisms of cognitive side effects of ECT.
Topics: Cognition; Electroconvulsive Therapy; Humans; Ketamine; Memantine; Triiodothyronine
PubMed: 35075641
DOI: 10.1111/acps.13397