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The Cochrane Database of Systematic... 2002The potassium channel blockers 4-aminopyridine (AP) and 3,4-diaminopyridine (DAP) increase nerve conduction in demyelinated nerve fibers, and have been proposed as a... (Review)
Review
BACKGROUND
The potassium channel blockers 4-aminopyridine (AP) and 3,4-diaminopyridine (DAP) increase nerve conduction in demyelinated nerve fibers, and have been proposed as a symptomatic therapy for people with multiple sclerosis (MS).
OBJECTIVES
To determine the efficacy and safety of aminopyridines for neurological deficits in MS people.
SEARCH STRATEGY
We searched CENTRAL (Issue 2, 2002), MEDLINE (January 1966-July 2002), EMBASE (1974-July 2002), and the Cochrane MS Group's Specialised Register. We hand searched bibliographic references from retrieved studies and recent MS symposia reports, and contacted known studies' investigators.
SELECTION CRITERIA
We included trials fulfilling all following criteria: randomised controlled trials (RCTs); adults with MS, out of exacerbation; AP or DAP treatment versus placebo; clinical endpoints.
DATA COLLECTION AND ANALYSIS
We identified 26 potentially pertinent studies. Three reviewers independently extracted data and assessed trial quality from 17 full-paper studies.
MAIN RESULTS
Six studies (eight publications, 198 participants, all crossover trials) were considered. Five studies assessed the efficacy of AP versus placebo, one compared DAP with active placebo. Treatment duration ranged from hours to six months. Median quality score of the studies was 3. Heterogeneity of outcome assessment and absence of information on individual study periods allowed quantitative pooling of results for few categorical variables. Of the 198 treated patients, there were six major side effects: one acute encephalopathy, three episodes of confusion, and two seizures. Three studies (54 patients) assessed manual muscle testing, with 29 patients (54%) improving in at least one muscular district during study treatment versus four patients (7%) during placebo (odds ratio [OR] 14.5, 95% confidence interval [CI] 4.7-43.7). Nine out of 54 participants (17%) improved in ambulation during study treatment versus none during placebo (p<0.001). A lower EDSS score was found in 13/198 participants during study treatment (7%) versus none during placebo (p<0.001). No improvement in neuropsychological tests was found in three trials assessing cognitive function. Finally, 47/136 MS people (35%) felt better when receiving the study drug, against 7(5%) on placebo (OR 9.7, 95% CI 4.3-22.0).
REVIEWER'S CONCLUSIONS
Currently available information allows no unbiased statement about safety or efficacy of aminopyridines for treating MS symptoms. Furthermore, we could not obtain any data on three unpublished RCTs (more than 300 participants). We conclude that publication bias remains a pervasive problem in this area, and that until the results of these unpublished studies are available to the scientific community, no confident estimate of effectiveness of aminopyridines in the management of MS symptoms is possible.
Topics: 4-Aminopyridine; Amifampridine; Cross-Over Studies; Humans; Multiple Sclerosis; Potassium Channel Blockers; Randomized Controlled Trials as Topic
PubMed: 12804404
DOI: 10.1002/14651858.CD001330 -
Nephrology, Dialysis, Transplantation :... May 2020We conducted a systematic review and meta-analysis to compare benefits and harms of different antihypertensive drug classes in kidney transplant recipients, as... (Comparative Study)
Comparative Study Meta-Analysis
BACKGROUND
We conducted a systematic review and meta-analysis to compare benefits and harms of different antihypertensive drug classes in kidney transplant recipients, as post-transplant hypertension (HTN) associates with increased cardiovascular (CV) morbidity and mortality.
METHODS
The Ovid-MEDLINE, PubMed and CENTRAL databases were searched for randomized controlled trials (RCTs) comparing all main antihypertensive agents versus placebo/no treatment, routine treatment.
RESULTS
The search identified 71 RCTs. Calcium channel blockers (CCBs) (26 trials) reduced the risk for graft loss {risk ratio [RR] 0.58 [95% confidence interval (CI) 0.38-0.89]}, increased glomerular filtration rate (GFR) [mean difference (MD) 3.08 mL/min (95% CI 0.38-5.78)] and reduced blood pressure (BP). Angiotensin-converting enzyme inhibitors (ACEIs) (13 trials) reduced the risk for graft loss [RR 0.62 (95% CI 0.40-0.96)] but decreased renal function and increased the risk for hyperkalaemia. Angiotensin receptor blockers (ARBs) (10 trials) did not modify the risk of death, graft loss and non-fatal CV events and increased the risk for hyperkalaemia. When pooling ACEI and ARB data, the risk for graft failure was lower in renin-angiotensin system (RAS) blockade as compared with control treatments. In direct comparison with ACEIs or ARBs (11 trials), CCBs increased GFR [MD 11.07 mL/min (95% CI 6.04-16.09)] and reduced potassium levels but were not more effective in reducing BP. There are few available data on mortality, graft loss and rejection. Very few studies performed comparisons with other active drugs.
CONCLUSIONS
CCBs could be the preferred first-step antihypertensive agents in kidney transplant patients, as they improve graft function and reduce graft loss. No definite patient or graft survival benefits were associated with RAS inhibitor use over conventional treatment.
Topics: Antihypertensive Agents; Glomerular Filtration Rate; Humans; Hypertension; Kidney Transplantation; Prognosis; Randomized Controlled Trials as Topic
PubMed: 31143926
DOI: 10.1093/ndt/gfz092 -
The Cochrane Database of Systematic... 2001Because of their ability to increase nerve conduction in demyelinated nerve fibers, potassium channel blockers 4-aminopyridine (AP) and 3,4-diaminopyridine (DAP) have... (Review)
Review
BACKGROUND
Because of their ability to increase nerve conduction in demyelinated nerve fibers, potassium channel blockers 4-aminopyridine (AP) and 3,4-diaminopyridine (DAP) have been proposed as a symptomatic therapy for people with multiple sclerosis (MS).
OBJECTIVES
To determine the efficacy and safety of aminopyridines in improving neurological deficits in people with MS.
SEARCH STRATEGY
Computerised general (MEDLINE, EMBASE) and specialised databases (Cochrane MS Group's trials register, CCTR). Hand search of bibliographic references from retrieved studies and recent MS symposia reports. Contact with principal investigators of known studies.
SELECTION CRITERIA
Trials were included if they fulfilled all following criteria: randomised controlled trials (RCTs); adults with MS, out of exacerbation; AP or DAP treatment versus placebo; clinical endpoints.
DATA COLLECTION AND ANALYSIS
We identified 26 potentially pertinent studies. Three reviewers independently extracted data and assessed trial quality from the 16 studies available as full papers.
MAIN RESULTS
Five studies (six publications) and 144 participants were considered in this review. Two more abstracts are awaiting assessment. All five studies were single-centre, double-blind, crossover trials. Four studies assessed the efficacy of AP versus placebo, one compared DAP with active placebo. The duration of treatment ranged from hours to three months. The median quality score of the studies was 3 (range 2-5). The heterogeneity of outcome assessment and the absence of information on individual study periods, allowed quantitative pooling of results for few categorical variables. Of the 144 treated patients, there were six major side effects: one acute encephalopathy, three episodes of confusion, and two seizures. Manual muscle testing was assessed in three studies (54 patients), with 29 patients (54%) improving in at least one muscular district during study treatment versus four patients (7%) during placebo (odds ratio [OR] 14.5, 95% confidence interval [CI] 4.7-43.7). Ambulation was assessed in three studies (54 patients): 9 patients (17%) improved during study treatment versus none during placebo (p<0.001). An improvement in EDSS score was found in 13 of the 144 participants during study treatment (9%) versus none during placebo (p<0.001). No improvement in neuropsychological tests was found in the two trials that evaluated cognitive function. Finally, 47 of 136 people with MS (35%) felt improved when receiving the study drug, against 7(5%) on placebo (OR 9.7, 95% CI 4.3-22.0).
REVIEWER'S CONCLUSIONS
Based on currently available information, no unbiased statement can be made about the safety or efficacy of aminopyridines for treating MS symptoms. Furthermore, we could not obtain any data on three unpublished RCTs involving more than 300 participants. We conclude that publication bias remains a pervasive problem in this area, and that until the results of these unpublished studies are available to the scientific community, no confident estimate of effectiveness of aminopyridines in the management of MS symptoms is possible.
Topics: 4-Aminopyridine; Amifampridine; Cross-Over Studies; Humans; Multiple Sclerosis; Potassium Channel Blockers; Randomized Controlled Trials as Topic
PubMed: 11687106
DOI: 10.1002/14651858.CD001330 -
Pharmacology Research & Perspectives Oct 2022The misattribution of an adverse drug reaction (ADR) as a symptom or illness can lead to the prescribing of additional medication, referred to as a prescribing cascade....
The misattribution of an adverse drug reaction (ADR) as a symptom or illness can lead to the prescribing of additional medication, referred to as a prescribing cascade. The aim of this systematic review is to identify published prescribing cascades in community-dwelling adults. A systematic review was reported in line with the PRISMA guidelines and pre-registered with PROSPERO. Electronic databases (Medline [Ovid], EMBASE, PsycINFO, CINAHL, Cochrane Library) and grey literature sources were searched. Inclusion criteria: community-dwelling adults; risk-prescription medication; outcomes-initiation of new medicine to "treat" or reduce ADR risk; study type-cohort, cross-sectional, case-control, and case-series studies. Title/abstract screening, full-text screening, data extraction, and methodological quality assessment were conducted independently in duplicate. A narrative synthesis was conducted. A total of 101 studies (reported in 103 publications) were included. Study sample sizes ranged from 126 to 11 593 989 participants and 15 studies examined older adults specifically (≥60 years). Seventy-eight of 101 studies reported a potential prescribing cascade including calcium channel blockers to loop diuretic (n = 5), amiodarone to levothyroxine (n = 5), inhaled corticosteroid to topical antifungal (n = 4), antipsychotic to anti-Parkinson drug (n = 4), and acetylcholinesterase inhibitor to urinary incontinence drugs (n = 4). Identified prescribing cascades occurred within three months to one year following initial medication. Methodological quality varied across included studies. Prescribing cascades occur for a broad range of medications. ADRs should be included in the differential diagnosis for patients presenting with new symptoms, particularly older adults and those who started a new medication in the preceding 12 months.
Topics: Acetylcholinesterase; Aged; Antifungal Agents; Antipsychotic Agents; Calcium Channel Blockers; Cholinesterase Inhibitors; Cross-Sectional Studies; Drug-Related Side Effects and Adverse Reactions; Humans; Independent Living; Sodium Potassium Chloride Symporter Inhibitors; Thyroxine
PubMed: 36123967
DOI: 10.1002/prp2.1008 -
Molecular Diagnosis & Therapy 2007Intensive blood glucose lowering can significantly reduce the risk of micro- and macrovascular complications in patients with diabetes mellitus. However, 30% of all... (Review)
Review
Intensive blood glucose lowering can significantly reduce the risk of micro- and macrovascular complications in patients with diabetes mellitus. However, 30% of all treated patients do not achieve optimal blood glucose levels. Genetic factors may influence the response to glucose-lowering medication. A search of MEDLINE-indexed literature published between January 1966 and July 2007 revealed 37 studies reporting data on genetic polymorphisms and response to glucose-lowering drugs. Most studies involving cytochrome P450 (CYP) genes had small sample sizes (21 studies <50 subjects) and were among healthy volunteers. Multiple studies indicated that the CYP2C9 *3 allele (Ile359Leu polymorphism) was associated with decreased clearance of sulfonylurea drugs. Supporting this, one study reported an increased insulin secretion in CYP2C9*3 allele carriers when using the sulfonylurea agent glyburide. The CYP2C9*3 allele was also associated with a decreased clearance of meglitinides, whereas the CYP2C8*3 (Arg139Lys; Lys399Arg) variant increased the clearance of meglitinides. Polymorphisms in genes encoding the inwardly rectifying potassium channel Kir6.2 (KCNJ11) and the insulin receptor substrate-1 (IRS1) were reported to be associated with an increased risk of (secondary) failure to respond to sulfonylurea therapy. A significant decrease in fasting plasma glucose and hemoglobin A(1c) (HbA(1c)) in response to rosiglitazone was seen in subjects carrying the Pro12Ala polymorphism of the peroxisome proliferator-activated receptor-gamma (PPARG) gene. Conversely, carriers of this polymorphism also had a higher conversion to diabetes mellitus when treated with acarbose; this effect was also seen in adiponectin (ADIPOQ) gene polymorphism carriers. Future studies with adequate sample sizes in which several SNPs in multiple candidate genes are genotyped in patients with diabetes should provide reliable information on genetic variants and response to glucose-lowering drugs.
Topics: Adiponectin; Cytochrome P-450 Enzyme System; Humans; Hypoglycemic Agents; PPAR gamma; Pharmacogenetics; Polymorphism, Genetic
PubMed: 17963417
DOI: 10.1007/BF03256250 -
International Journal of Cardiology.... Feb 2020Sigma-1 receptors are ligand-regulated chaperone proteins, involved in several cellular mechanisms. The aim of this systematic review was to examine the effects that the... (Review)
Review
Sigma-1 receptors are ligand-regulated chaperone proteins, involved in several cellular mechanisms. The aim of this systematic review was to examine the effects that the sigma-1 receptor has on the cardiovascular system. The interaction targets and proposed mechanisms of action of sigma-1 receptors were explored, with the aim of determining if the sigma-1 receptor is a potential pharmacological target for cardiac pathologies. This systematic review was conducted according to the PRISMA guidelines and these were used to critically appraise eligible studies. Pubmed and Scopus were systematically searched for articles investigating sigma-1 receptors in the cardiovascular system. Papers identified by the search terms were then subject to analysis against pre-determined inclusion criteria. 23 manuscripts met the inclusion criteria and were included in this review. The experimental platforms, experimental techniques utilised and the results of the studies were summarised. The sigma-1 receptor is found to be implicated in cardioprotection, via various mechanisms including stimulating the Akt-eNOS pathway, and reduction of Ca2 + leakage into the cytosol via modulating certain calcium channels. Sigma-1 receptors are also found to modulate other cardiac ion channels including different subtypes of potassium and sodium channels and have been shown to modulate intracardiac neuron excitability. The sigma-1 receptor is a potential therapeutic target for treatment of cardiac pathologies, particularly cardiac hypertrophy. We therefore suggest investigating the cardioprotective mechanisms of sigma-1 receptor function, alongside proposed potential ligands that can stimulate these functions.
PubMed: 31909177
DOI: 10.1016/j.ijcha.2019.100449 -
The Cochrane Database of Systematic... Nov 2012Potassium-sparing diuretics, which block the epithelial sodium channel (ENaC), are widely prescribed for hypertension as a second-line drug in patients taking other... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Potassium-sparing diuretics, which block the epithelial sodium channel (ENaC), are widely prescribed for hypertension as a second-line drug in patients taking other diuretics (e.g. thiazide diuretics) and much less commonly prescribed as monotherapy. Therefore, it is essential to determine the effects of ENaC blockers on blood pressure (BP), heart rate and withdrawals due to adverse effects (WDAEs) when given as a first-line or second-line therapy.
OBJECTIVES
To quantify the dose-related reduction in systolic blood pressure (SBP) and diastolic blood pressure (DBP) of ENaC blocker therapy as a first-line or second-line drug in patients with primary hypertension.
SEARCH METHODS
We searched CENTRAL (The Cochrane Library 2012), MEDLINE (1950 to August 2012), EMBASE (1980 to August 2012) and reference lists of articles.
SELECTION CRITERIA
Double-blind, randomized, controlled trials in patients with primary hypertension that evaluate, for a duration of 3 to 12 weeks, the BP lowering efficacy of: 1) fixed-dose monotherapy with an ENaC blocker compared with placebo; or 2) an ENaC blocker in combination with another class of anti-hypertensive drugs compared with the respective monotherapy (without an ENaC blocker).
DATA COLLECTION AND ANALYSIS
Two authors independently assessed the risk of bias and extracted data. Study authors were contacted for additional information. WDAE information was also collected from the trials.
MAIN RESULTS
No trials evaluating the BP lowering efficacy of ENaC blockers as monotherapy in patients with primary hypertension were identified. Only 6 trials evaluated the BP lowering efficacy of low doses of amiloride and triamterene as a second drug in 496 participants with a baseline BP of 151/102 mm Hg. The additional BP reduction caused by the ENaC blocker as a second drug was estimated by comparing the difference in BP reduction between the combination and monotherapy groups. The addition of low doses of amiloride and triamterene in these trials did not reduce BP. An estimate of the dose-related BP lowering efficacy for ENaC blockers was not possible because of a lack of trial data at higher doses.
AUTHORS' CONCLUSIONS
ENaC blockers do not have a statistically or clinically significant BP lowering effect at low doses but trials at higher doses are not available. The review did not provide a good estimate of the incidence of harms associated with ENaC blockers.
Topics: Amiloride; Antihypertensive Agents; Blood Pressure; Diuretics; Dose-Response Relationship, Drug; Drug Therapy, Combination; Humans; Hypertension; Randomized Controlled Trials as Topic; Sodium Channel Blockers; Triamterene
PubMed: 23152254
DOI: 10.1002/14651858.CD008167.pub3 -
Health Technology Assessment... 2000Multiple sclerosis (MS) is an important problem both for people with the disease and for society. There is no cure, and alleviation of symptoms forms the cornerstone of... (Review)
Review
BACKGROUND
Multiple sclerosis (MS) is an important problem both for people with the disease and for society. There is no cure, and alleviation of symptoms forms the cornerstone of care. Excessive fatigue that severely limits activity is experienced by at least two-thirds of the estimated 60,000 people with MS in the UK.
OBJECTIVES
(1) To identify current treatments for fatigue in MS and their evidence-base. (2) To systematically review the evidence for those treatments that have been investigated in more than one rigorous study, in order to determine their effectiveness and cost-effectiveness.
METHODS
The review was carried out in two stages: a formal scoping review (to assess the range of interventions used by people with MS), and a systematic review for treatments that had been identified as promising and that had been investigated in clinical trials (as identified in the scoping review). A systematic review of research on costs and cost-effectiveness of those interventions identified as promising was also performed. Electronic databases, including MEDLINE and EMBASE, were searched for the period 1991-June 1999 (scoping review) and 1966-December 1999 (systematic review). Reference lists from publications were also searched, and experts were contacted for any additional information not already identified.
RESULTS
Interventions identified for the treatment of fatigue in MS (1) Behavioural advice. This is the main element of initial clinical management and no rigorous research of its effectiveness was identified. (2) Drugs (amantadine, pemoline, potassium-channel blockers and antidepressants). (3) Training, rehabilitation and devices (cooling vests and electromagnetic fields). (4) Alternative therapies (bee venom, cannabis, acupuncture/acupressure and yoga). Only two drugs, amantadine and pemoline, met the criteria for full systematic review. RESULTS - EFFECTIVENESS OF AMANTADINE: One parallel and three crossover trials were found, involving a total of 236 people with MS. All studies were open to bias. All studies showed a pattern in favour of amantadine compared with placebo, but there is considerable uncertainty about the validity and clinical significance of this finding. This pattern of benefit was considerably undermined when different assumptions were used in the sensitivity analysis. RESULTS - EFFECTIVENESS OF PEMOLINE: One parallel and one crossover trial were found involving a total of 126 people with MS. Both studies were open to bias. There was no overall tendency in favour of pemoline over placebo and an excess of reports of adverse effects with pemoline. RESULTS - HEALTH ECONOMIC ANALYSIS: The drug costs of amantadine and pemoline are modest (pound 200 and pound 80 per annum, respectively). No economic evaluations were identified in the systematic review, and available data were insufficient to allow modelling of cost-effectiveness in this rapid review.
CONCLUSIONS
There is insufficient evidence to allow people with MS, clinicians or policy makers to make informed decisions on the appropriate use of the many treatments on offer. Only amantadine appears to have some proven ability to alleviate the fatigue in MS, though only a proportion of users will obtain benefit and then only some of these patients will benefit sufficiently to take the drug in the long term. CONCLUSIONS - RECOMMENDATIONS FOR RESEARCH: The frequency, severity and impact of fatigue, the poverty of available research, and the absence of any ongoing research, suggest that new research is an urgent priority. People with MS, clinicians and policy makers should work together to ensure that the evidence required is collected as quickly as possible by encouraging involvement in rigorous research. Research should not be restricted to the two drugs reviewed in depth in this report. All interventions identified in the scoping review (see above) should be considered, as should basic scientific research into the underlying mechanism of fatigue in MS.
Topics: Amantadine; Central Nervous System Stimulants; Cost-Benefit Analysis; Dopamine Agents; Evidence-Based Medicine; Fatigue; Humans; Multiple Sclerosis; Pemoline
PubMed: 11074395
DOI: No ID Found -
British Journal of Clinical Pharmacology Dec 2022Despite numerous studies on quinidine therapies for epilepsies associated with KCNT1 gene mutations, there is no consensus on its clinical utility. Thus, we reviewed... (Review)
Review
AIMS
Despite numerous studies on quinidine therapies for epilepsies associated with KCNT1 gene mutations, there is no consensus on its clinical utility. Thus, we reviewed studies evaluating the efficacy and safety of quinidine in KCNT1-related epileptic disorders.
METHODS
Electronic databases were queried for in vivo and in vitro studies on quinidine therapy in KCNT1-related epilepsies published on or before 1 May 2022. The evaluation of evidence was done as per the American Academy of Neurology's classification scheme. Identification of significant factors that possibly influenced therapeutic effects of quinidine were performed using χ tests.
RESULTS
Twenty-seven studies containing 82 patient records were reviewed. Records of 80 patients with 33 KCNT1 mutations were analysed, of which 20 patients had gained ≥50% seizure reduction due to quinidine therapy. However, quinidine therapy often had different effects on patients with the same KCNT1 mutation. Age, genotypes of KCNT1 mutations, seizure types and brain MRI did not significantly influence the therapeutic effect of quinidine. Prolonged QTc was the most common among all adverse events with quinidine. Notably, results of in vitro quinidine tests did not correspond with in vivo tests.
CONCLUSIONS
Therapeutic effects of quinidine on KCNT1-related epilepsies remained indefinite as contradictory results were detected in similar patients. Age, seizure types, genotypes of KCNT1 mutations and brain MRI did not influence the therapeutic effects of quinidine. Insensitivity to quinidine by a certain Kcnt1 genotype in molecular tests is predictive of its inefficacy in human populations of the respective mutation.
Topics: Humans; Quinidine; Potassium Channels, Sodium-Activated; Anticonvulsants; Nerve Tissue Proteins; Epilepsy; Seizures; Mutation
PubMed: 35940594
DOI: 10.1111/bcp.15479 -
Cells Oct 2021A serotonergic dysfunction has been largely postulated as the main cause of depression, mainly due to its effective response to drugs that increase the serotonergic...
A serotonergic dysfunction has been largely postulated as the main cause of depression, mainly due to its effective response to drugs that increase the serotonergic tone, still currently the first therapeutic line in this mood disorder. However, other dysfunctional pathomechanisms are likely involved in the disorder, and this may in part explain why some individuals with depression are resistant to serotonergic therapies. Among these, emerging evidence suggests a role for the astrocytic inward rectifier potassium channel 4.1 (Kir4.1) as an important modulator of neuronal excitability and glutamate metabolism. To discuss the relationship between Kir4.1 dysfunction and depression, a systematic review was performed according to the PRISMA statement. Searches were conducted across PubMed, Scopus, and Web of Science by two independent reviewers. Twelve studies met the inclusion criteria, analyzing Kir4.1 relationships with depression, through in vitro, in vivo, and investigations. Increasing, yet not conclusive, evidence suggests a potential pathogenic role for Kir4.1 upregulation in depression. However, the actual contribution in the diverse subtypes of the disorder and in the comorbid conditions, for example, the epilepsy-depression comorbidity, remain elusive. Further studies are needed to better define the clinical phenotype associated with Kir4.1 dysfunction in humans and the molecular mechanisms by which it contributes to depression and implications for future treatments.
Topics: Antidepressive Agents; Antidepressive Agents, Tricyclic; Astrocytes; Brain-Derived Neurotrophic Factor; Depression; Down-Regulation; Humans; Ketamine; Potassium Channels, Inwardly Rectifying; Selective Serotonin Reuptake Inhibitors; Up-Regulation
PubMed: 34685608
DOI: 10.3390/cells10102628