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Circulation Oct 2018Among his major cardiac electrophysiological contributions, Miles Vaughan Williams (1918-2016) provided a classification of antiarrhythmic drugs that remains central to...
BACKGROUND
Among his major cardiac electrophysiological contributions, Miles Vaughan Williams (1918-2016) provided a classification of antiarrhythmic drugs that remains central to their clinical use.
METHODS
We survey implications of subsequent discoveries concerning sarcolemmal, sarcoplasmic reticular, and cytosolic biomolecules, developing an expanded but pragmatic classification that encompasses approved and potential antiarrhythmic drugs on this centenary of his birth.
RESULTS
We first consider the range of pharmacological targets, tracking these through to cellular electrophysiological effects. We retain the original Vaughan Williams Classes I through IV but subcategorize these divisions in light of more recent developments, including the existence of Na current components (for Class I), advances in autonomic (often G protein-mediated) signaling (for Class II), K channel subspecies (for Class III), and novel molecular targets related to Ca homeostasis (for Class IV). We introduce new classes based on additional targets, including channels involved in automaticity, mechanically sensitive ion channels, connexins controlling electrotonic cell coupling, and molecules underlying longer-term signaling processes affecting structural remodeling. Inclusion of this widened range of targets and their physiological sequelae provides a framework for a modernized classification of established antiarrhythmic drugs based on their pharmacological targets. The revised classification allows for the existence of multiple drug targets/actions and for adverse, sometimes actually proarrhythmic, effects. The new scheme also aids classification of novel drugs under investigation.
CONCLUSIONS
We emerge with a modernized classification preserving the simplicity of the original Vaughan Williams framework while aiding our understanding and clinical management of cardiac arrhythmic events and facilitating future developments in this area.
Topics: Action Potentials; Animals; Anti-Arrhythmia Agents; Arrhythmias, Cardiac; Calcium Channel Blockers; Heart Conduction System; Heart Rate; Humans; Ion Channels; Membrane Transport Modulators; Neurotransmitter Agents; Potassium Channel Blockers; Terminology as Topic; Voltage-Gated Sodium Channel Blockers
PubMed: 30354657
DOI: 10.1161/CIRCULATIONAHA.118.035455 -
Neurological Sciences : Official... Apr 2021Movement disorders have been described in the context of different types of encephalitis. Among hyperkinetic manifestations, tics have sporadically been reported in... (Review)
Review
BACKGROUND
Movement disorders have been described in the context of different types of encephalitis. Among hyperkinetic manifestations, tics have sporadically been reported in cases of encephalitis resulting from a range of aetiologies.
OBJECTIVE
This review aimed to assess the prevalence and characteristics of tics in patients with encephalitis.
METHODS
We conducted a systematic literature review of original studies on the major scientific databases, according to the standards outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.
RESULTS
In addition to the established association between tics and encephalitis lethargica, our literature search identified reports of tics in patients with immune-mediated pathologies (including autoimmune encephalitides affecting the N-methyl-D-aspartate receptor, voltage-gated potassium channels, and glycine receptors) and infective processes (ranging from relatively common viral pathogens, such as herpes simplex, to prions, as in Creutzfeldt-Jakob disease). Tics were most commonly reported in the post-encephalitic period and involvement of the basal ganglia was frequently observed.
DISCUSSION
The association of new-onset tics and encephalitis, in the background of other neuropsychiatric abnormalities, has practical implications, potentially improving the detection of encephalitis based on clinical features. Future research should focus on the categorisation and treatment of hyperkinetic movement disorders associated with encephalitis.
Topics: Basal Ganglia; Encephalitis; Humans; Tic Disorders; Tics; Tourette Syndrome
PubMed: 33486621
DOI: 10.1007/s10072-021-05065-w -
BMJ Clinical Evidence Oct 2008Stable angina is usually caused by coronary atherosclerosis, and affects up to 16% of men and 10% of women aged 65-74 years in the UK. Risk factors include hypertension,... (Review)
Review
INTRODUCTION
Stable angina is usually caused by coronary atherosclerosis, and affects up to 16% of men and 10% of women aged 65-74 years in the UK. Risk factors include hypertension, elevated serum cholesterol levels, smoking, physical inactivity, and overweight. People with angina are at increased risk of other cardiovascular events and mortality compared with people without angina. Among people not thought to need coronary artery revascularisation, annual mortality is 1-2% and the annual non-fatal myocardial infarction (MI) rate is 2-3%.
METHODS AND OUTCOMES
We conducted a systematic review and aimed to answer the following clinical question: What are effects of long-term drug treatment for stable angina? We searched: Medline, Embase, The Cochrane Library, and other important databases up to June 2007 (BMJ Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
RESULTS
We found nine systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
CONCLUSIONS
In this systematic review we present information relating to the long-term effectiveness and safety of the following interventions: beta-blockers, calcium channel blockers, long-acting nitrates, potassium channel openers, combinations of these anti-anginal drug treatments and the use of these anti-anginal drug treatment as an adjunct to existing therapies.
Topics: Adrenergic beta-Antagonists; Angina Pectoris; Calcium Channel Blockers; Cardiovascular Agents; Humans; Incidence; Myocardial Infarction; Prospective Studies; Risk Factors
PubMed: 19445795
DOI: No ID Found -
Psychiatry and Clinical Neurosciences Oct 2017Antibodies to the voltage-gated potassium channel (VGKC) complex and glutamic acid decarboxylase (GAD) have been reported in some cases of psychosis. We conducted the... (Meta-Analysis)
Meta-Analysis Review
Antibodies to the voltage-gated potassium channel (VGKC) complex and glutamic acid decarboxylase (GAD) have been reported in some cases of psychosis. We conducted the first systematic review and meta-analysis to investigate their prevalence in people with psychosis and report a case series of VGKC-complex antibodies in refractory psychosis. Only five studies presenting prevalence rates of VGKC seropositivity in psychosis were identified, in addition to our case series, with an overall prevalence of 1.5% (25/1720) compared to 0.7% in healthy controls (12/1753). Meta-analysis established that the pooled prevalence of GAD65 autoantibodies was 5.8% (95% confidence interval [CI]: 2.0-15.6%; I = 91%; nine studies) in psychotic disorders, with a prevalence of 4.6% (95%CI: 1.2-15.9%; nine studies; I = 89%) and 6.2% (95%CI: 1.2-27.0%; two studies; I = 69%) in schizophrenia and bipolar disorder, respectively. People with psychosis were more likely to have GAD65 antibodies than controls (odds ratio [OR], 2.24; 95%CI: 1.28-3.92%; P = 0.005; eight studies; I = 0%). Among 21 participants with treatment-resistant psychosis, none had VGKC antibodies. The prevalence of VGKC antibodies is low in psychosis. Our preliminary meta-analysis suggests that GAD autoantibodies are more common in people with psychosis than in controls, although few studies accounted for the possibility of co-existing type 1 diabetes mellitus and the clinical significance of reported GAD titers remains unclear. The paucity of studies reporting thresholds for defining GAD abnormality and rates of comorbid type 1 diabetes mellitus precludes interpretations regarding the influence of GAD antibodies on the development of psychotic disorders and may have led to an overestimate of the prevalence of GAD. Our case series fails to support the hypothesis that VGKC antibodies are linked to treatment resistance in psychosis, but the literature to date is remarkably sparse.
Topics: Autoantibodies; Glutamate Decarboxylase; Humans; Potassium Channels, Voltage-Gated; Psychotic Disorders
PubMed: 28573688
DOI: 10.1111/pcn.12543 -
The Cochrane Database of Systematic... Oct 2020Treatment with angiotensin-converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB) is used to reduce proteinuria and retard the progression of... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Treatment with angiotensin-converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB) is used to reduce proteinuria and retard the progression of chronic kidney disease (CKD). However, resolution of proteinuria may be incomplete with these therapies and the addition of an aldosterone antagonist may be added to further prevent progression of CKD. This is an update of a Cochrane review first published in 2009 and updated in 2014.
OBJECTIVES
To evaluate the effects of aldosterone antagonists (selective (eplerenone), non-selective (spironolactone or canrenone), or non-steroidal mineralocorticoid antagonists (finerenone)) in adults who have CKD with proteinuria (nephrotic and non-nephrotic range) on: patient-centred endpoints including kidney failure (previously know as end-stage kidney disease (ESKD)), major cardiovascular events, and death (any cause); kidney function (proteinuria, estimated glomerular filtration rate (eGFR), and doubling of serum creatinine); blood pressure; and adverse events (including hyperkalaemia, acute kidney injury, and gynaecomastia).
SEARCH METHODS
We searched the Cochrane Kidney and Transplant Register of Studies up to 13 January 2020 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal, and ClinicalTrials.gov.
SELECTION CRITERIA
We included randomised controlled trials (RCTs) and quasi-RCTs that compared aldosterone antagonists in combination with ACEi or ARB (or both) to other anti-hypertensive strategies or placebo in participants with proteinuric CKD.
DATA COLLECTION AND ANALYSIS
Two authors independently assessed study quality and extracted data. Data were summarised using random effects meta-analysis. We expressed summary treatment estimates as a risk ratio (RR) for dichotomous outcomes and mean difference (MD) for continuous outcomes, or standardised mean difference (SMD) when different scales were used together with their 95% confidence interval (CI). Risk of bias were assessed using the Cochrane tool. Evidence certainty was evaluated using GRADE.
MAIN RESULTS
Forty-four studies (5745 participants) were included. Risk of bias in the evaluated methodological domains were unclear or high risk in most studies. Adequate random sequence generation was present in 12 studies, allocation concealment in five studies, blinding of participant and investigators in 18 studies, blinding of outcome assessment in 15 studies, and complete outcome reporting in 24 studies. All studies comparing aldosterone antagonists to placebo or standard care were used in addition to an ACEi or ARB (or both). None of the studies were powered to detect differences in patient-level outcomes including kidney failure, major cardiovascular events or death. Aldosterone antagonists had uncertain effects on kidney failure (2 studies, 84 participants: RR 3.00, 95% CI 0.33 to 27.65, I² = 0%; very low certainty evidence), death (3 studies, 421 participants: RR 0.58, 95% CI 0.10 to 3.50, I² = 0%; low certainty evidence), and cardiovascular events (3 studies, 1067 participants: RR 0.95, 95% CI 0.26 to 3.56; I² = 42%; low certainty evidence) compared to placebo or standard care. Aldosterone antagonists may reduce protein excretion (14 studies, 1193 participants: SMD -0.51, 95% CI -0.82 to -0.20, I² = 82%; very low certainty evidence), eGFR (13 studies, 1165 participants, MD -3.00 mL/min/1.73 m², 95% CI -5.51 to -0.49, I² = 0%, low certainty evidence) and systolic blood pressure (14 studies, 911 participants: MD -4.98 mmHg, 95% CI -8.22 to -1.75, I² = 87%; very low certainty evidence) compared to placebo or standard care. Aldosterone antagonists probably increase the risk of hyperkalaemia (17 studies, 3001 participants: RR 2.17, 95% CI 1.47 to 3.22, I² = 0%; moderate certainty evidence), acute kidney injury (5 studies, 1446 participants: RR 2.04, 95% CI 1.05 to 3.97, I² = 0%; moderate certainty evidence), and gynaecomastia (4 studies, 281 participants: RR 5.14, 95% CI 1.14 to 23.23, I² = 0%; moderate certainty evidence) compared to placebo or standard care. Non-selective aldosterone antagonists plus ACEi or ARB had uncertain effects on protein excretion (2 studies, 139 participants: SMD -1.59, 95% CI -3.80 to 0.62, I² = 93%; very low certainty evidence) but may increase serum potassium (2 studies, 121 participants: MD 0.31 mEq/L, 95% CI 0.17 to 0.45, I² = 0%; low certainty evidence) compared to diuretics plus ACEi or ARB. Selective aldosterone antagonists may increase the risk of hyperkalaemia (2 studies, 500 participants: RR 1.62, 95% CI 0.66 to 3.95, I² = 0%; low certainty evidence) compared ACEi or ARB (or both). There were insufficient studies to perform meta-analyses for the comparison between non-selective aldosterone antagonists and calcium channel blockers, selective aldosterone antagonists plus ACEi or ARB (or both) and nitrate plus ACEi or ARB (or both), and non-steroidal mineralocorticoid antagonists and selective aldosterone antagonists.
AUTHORS' CONCLUSIONS
The effects of aldosterone antagonists when added to ACEi or ARB (or both) on the risks of death, major cardiovascular events, and kidney failure in people with proteinuric CKD are uncertain. Aldosterone antagonists may reduce proteinuria, eGFR, and systolic blood pressure in adults who have mild to moderate CKD but may increase the risk of hyperkalaemia, acute kidney injury and gynaecomastia when added to ACEi and/or ARB.
Topics: Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Bias; Calcium Channel Blockers; Canrenone; Disease Progression; Eplerenone; Humans; Hyperkalemia; Kidney Failure, Chronic; Mineralocorticoid Receptor Antagonists; Naphthyridines; Proteinuria; Randomized Controlled Trials as Topic; Spironolactone
PubMed: 33107592
DOI: 10.1002/14651858.CD007004.pub4 -
Frontiers in Genetics 2020Intellectual disability (ID) manifests prior to adulthood as severe limitations to intellectual function and adaptive behavior. The role of potassium channelopathies in...
Intellectual disability (ID) manifests prior to adulthood as severe limitations to intellectual function and adaptive behavior. The role of potassium channelopathies in ID is poorly understood. Therefore, we aimed to evaluate the relationship between ID and potassium channelopathies. We hypothesized that potassium channelopathies are strongly associated with ID initiation, and that both gain- and loss-of-function mutations lead to ID. This systematic review explores the burden of potassium channelopathies, possible mechanisms, advancements using animal models, therapies, and existing gaps. The literature search encompassed both PubMed and Embase up to October 2019. A total of 75 articles describing 338 cases were included in this review. Nineteen channelopathies were identified, affecting the following genes: , and . Twelve of these genes presented both gain- and loss-of-function properties, three displayed gain-of-function only, three exhibited loss-of-function only, and one had unknown function. How gain- and loss-of-function mutations can both lead to ID remains largely unknown. We identified only a few animal studies that focused on the mechanisms of ID in relation to potassium channelopathies and some of the few available therapeutic options (channel openers or blockers) appear to offer limited efficacy. In conclusion, potassium channelopathies contribute to the initiation of ID in several instances and this review provides a comprehensive overview of which molecular players are involved in some of the most prominent disease phenotypes.
PubMed: 32655623
DOI: 10.3389/fgene.2020.00614 -
Nutrients Sep 2023Hypertension is the leading preventable risk factor for cardiovascular disease and all-cause mortality worldwide. However, studies have shown increased risk of mortality... (Meta-Analysis)
Meta-Analysis Review
Hypertension is the leading preventable risk factor for cardiovascular disease and all-cause mortality worldwide. However, studies have shown increased risk of mortality from heart disease and stroke even within the normal blood pressure (BP) range, starting at BPs above 110-115/70-75 mm Hg. Nutraceuticals, such as vitamins and minerals, have been studied extensively for their efficacy in lowering BP and may be of benefit to the general, normotensive population in achieving optimal BP. Our study investigated the effects of six nutraceuticals (Vitamins: C, D, E; Minerals: Calcium, Magnesium, Potassium) on both systolic blood pressure (SBP) and diastolic blood pressure (DBP) in this population. We performed a systematic review and pairwise meta-analysis for all six supplements versus placebo. Calcium and magnesium achieved significant reductions in both SBP and DBP of -1.37/-1.63 mm Hg and -2.79/-1.56 mm Hg, respectively. Vitamin E and potassium only yielded significant reductions in SBP with values of -1.76 mm Hg and -2.10 mm Hg, respectively. Vitamins C and D were not found to significantly lower either SBP or DBP. Future studies should determine optimal dosage and treatment length for these supplements in the general, normotensive population.
Topics: Humans; Vitamins; Blood Pressure; Magnesium; Calcium; Dietary Supplements; Hypertension; Minerals; Hypotension; Calcium, Dietary; Potassium; Antihypertensive Agents
PubMed: 37836507
DOI: 10.3390/nu15194223 -
American Journal of Physiology.... Apr 2016Inflammatory bowel disease (IBD) is a chronic inflammatory disorder with a complex pathogenesis. Diarrhea is a highly prevalent and often debilitating symptom of IBD... (Review)
Review
Inflammatory bowel disease (IBD) is a chronic inflammatory disorder with a complex pathogenesis. Diarrhea is a highly prevalent and often debilitating symptom of IBD patients that results, at least in part, from an intestinal hydroelectrolytic imbalance. Evidence suggests that reduced electrolyte absorption is more relevant than increased secretion to this disequilibrium. This systematic review analyses and integrates the current evidence on the roles of epithelial Na(+)-K(+)-ATPase (NKA), Na(+)/H(+) exchangers (NHEs), epithelial Na(+) channels (ENaC), and K(+) channels (KC) in IBD-associated diarrhea. NKA is the key driving force of the transepithelial ionic transport and its activity is decreased in IBD. In addition, the downregulation of apical NHE and ENaC and the upregulation of apical large-conductance KC all contribute to the IBD-associated diarrhea by lowering sodium absorption and/or increasing potassium secretion.
Topics: Animals; Epithelial Cells; Epithelial Sodium Channels; Gastrointestinal Absorption; Gastrointestinal Agents; Humans; Inflammatory Bowel Diseases; Intestinal Mucosa; Ion Transport; Membrane Transport Modulators; Potassium Channels; Signal Transduction; Sodium-Hydrogen Exchangers; Sodium-Potassium-Exchanging ATPase
PubMed: 26744474
DOI: 10.1152/ajpgi.00369.2015 -
Frontiers in Pharmacology 2022Potassium ion (K) channels are pore-forming transmembrane proteins that control the transport of K ions. Medicinal plants are widely used as complementary therapies for... (Review)
Review
Potassium ion (K) channels are pore-forming transmembrane proteins that control the transport of K ions. Medicinal plants are widely used as complementary therapies for several disorders. Studies have shown that the modulation of K channels is most likely involved in various pharmacological effects of medicinal plants. This review aimed to evaluate the modulatory effects of medicinal plants and their active constituents on K channels under pathological conditions. This systematic review was prepared according to the Preferred Reporting Items for the Systematic Reviews and Meta-analyses (PRISMA) 2020 guideline. Four databases, including PubMed, Web of Science, embase, and Scopus, were searched. We identified 687 studies from these databases, from which we selected 13 studies for the review by using the Population, Intervention, Comparison, Outcomes, Study (PICOS) tool. The results of the 13 selected studies showed a modulatory effect of medicinal plants or their active constituents on ATP-sensitive potassium channels (K), and small (SK) and large (BK) conductance calcium-activated K channels in several pathological conditions such as nociception, brain ischemia, seizure, diabetes, gastric ulcer, myocardial ischemia-reperfusion, and hypertension via possible involvement of the nitric oxide/cyclic GMP pathway and protein kinase. K channels should be considered as significant therapeutic milestones in the treatment of several diseases. We believe that understanding the mechanism behind the interaction of medicinal plants with K channels can facilitate drug development for the treatment of various K channel-related disorders.
PubMed: 35273505
DOI: 10.3389/fphar.2022.831963 -
The Cochrane Database of Systematic... Jan 2008Primary periodic paralyses are rare inherited muscle diseases characterised by episodes of flaccid weakness affecting one or more limbs, lasting several hours to several... (Review)
Review
BACKGROUND
Primary periodic paralyses are rare inherited muscle diseases characterised by episodes of flaccid weakness affecting one or more limbs, lasting several hours to several days, caused by mutations in skeletal muscle channel genes.
OBJECTIVES
The objective of this review was to systematically review treatment of periodic paralyses.
SEARCH STRATEGY
We searched the Cochrane Neuromuscular Disease Group Trials Register, MEDLINE (from January 1966 to July 2007), and EMBASE (from January 1980 to July 2007) and any other available international medical library sources from the University of Milan for randomised trials.
SELECTION CRITERIA
We included randomised (including cross-over studies) and quasi-randomised trials in participants with primary periodic paralyses, in which any form of treatment, including physical therapy and alternative therapies, was compared to placebo or another treatment.
DATA COLLECTION AND ANALYSIS
Our primary outcome measure was the change in attack severity or frequency by eight weeks from the start of treatment. Our secondary outcome measures were: change in muscle strength and mass; change in Quality of Life, using Short Form 36 (SF36) or similar; preference of treatment strategy; adverse effects at eight weeks.
MAIN RESULTS
Three studies met our inclusion criteria. In one study dichlorphenamide (DCP) vs placebo was tested in two groups of participants: 42 with hypokalemic periodic paralysis (HypoPP) and 31 with hyperkalemic periodic paralysis (HyperPP), based on clinical criteria. Thirty-four of 42 participants with hypokalemic periodic paralysis completed both treatment phases. For the 34 participants having attack rate data for both treatment phases, the mean improvement in attack rate (P = 0.02) and severity-weighted attack rate (P = 0.01) on DCP relative to placebo were statistically significant. Fifteen preferred DCP, three placebo and six their baseline medication. Twenty-four of 31 participants with hyperkalemic periodic paralysis completed both treatment phases: for the 16 participants who had attack rate data for both treatment phases, the mean improvement in attack rate (P = 0.006) and in severity-weighted attack rate (P = 0.02) on DCP relative to placebo were significant. Fifteen preferred DCP, one placebo and five their baseline medication. Acetazolamide proved to improve muscle strength in eight participants with HypoPP in one other study and pinacidil, a potassium channel opener, also improved muscle strength in 2/4 participants with HypoPP in a third study.
AUTHORS' CONCLUSIONS
The largest included study that met our inclusion criteria suggested that DCP was effective in the prevention of episodic weakness in both hypokalemic and hyperkalemic periodic paralyses. The other two studies provide some evidence that either acetazolamide or pinacidil may improve muscle strength. However we still lack sufficient evidence to provide full guidelines for the treatment of people with periodic paralysis.
Topics: Acetazolamide; Carbonic Anhydrase Inhibitors; Dichlorphenamide; Humans; Hypokalemic Periodic Paralysis; Paralysis, Hyperkalemic Periodic; Pinacidil; Randomized Controlled Trials as Topic
PubMed: 18254068
DOI: 10.1002/14651858.CD005045.pub2